diff --git a/tests/test_managed_runtime_resolution.py b/tests/test_managed_runtime_resolution.py
index e3943e351a..bb136069f4 100644
--- a/tests/test_managed_runtime_resolution.py
+++ b/tests/test_managed_runtime_resolution.py
@@ -92,7 +92,7 @@ _ALLOWED: dict[tuple[str, str], str] = {
     ("hermes_cli/main.py", "npm"): (
         "Same _ensure_tui_node() gate as node."
     ),
-    ("tools/browser_tool.py", "npx"): (
+    ("tools/browser_tool_install.py", "npx"): (
         "agent-browser runs via `npx`, resolved against the extended browser "
         "PATH that _merge_browser_path() already seeds with the managed dirs."
     ),
diff --git a/tests/tools/test_browser_secret_exfil.py b/tests/tools/test_browser_secret_exfil.py
index 5a15d310a1..0d5efb4274 100644
--- a/tests/tools/test_browser_secret_exfil.py
+++ b/tests/tools/test_browser_secret_exfil.py
@@ -296,7 +296,6 @@ class TestBrowserSupervisorRedaction:
                 closed_by="agent",
             ),),
             frame_tree={"top": {"frame_id": "f1", "url": "about:blank", "origin": "null", "is_oopif": False}},
-            console_errors=(),
             active=True,
             cdp_url="ws://example.invalid/devtools/browser/mock",
             task_id="test",
diff --git a/tools/browser_cdp_tool.py b/tools/browser_cdp_tool.py
index 59db34baa3..dd585bb53f 100644
--- a/tools/browser_cdp_tool.py
+++ b/tools/browser_cdp_tool.py
@@ -32,7 +32,6 @@ _CDP_PRIVATE_PAGE_ALLOWED_METHODS = {
     "Page.stopLoading",
 }
 
-
 # method → result paths that are ALWAYS opaque base64 (protocol-declared binary).
 # redact_sensitive_text's Fernet pattern ("gAAAA" + base64 alphabet) can match
 # arbitrary spans inside such payloads and corrupt the decoded bytes; the payload
@@ -55,49 +54,41 @@ _CDP_FLAGGED_BINARY_PATHS: Dict[str, tuple] = {
 }
 
 
-def _redact_cdp_output(
-    value: Any,
-    *,
-    always_paths: tuple = (),
-    flagged_paths: tuple = (),
-) -> Any:
+def _redact_cdp_output(value: Any, *, always_paths: tuple = (), flagged_paths: tuple = ()) -> Any:
     """Redact browser-originated CDP result text; opaque bytes stay byte-identical.
 
     Exemptions come ONLY from the calling method's spec as exact result paths.
     Path suffixes propagate only into the matching subtree, so ``base64Encoded``
     is honored solely as a sibling on the trusted carrier object — never as
-    ambient trust a ``Runtime.evaluate`` by-value object could spoof (#94142).
+    ambient trust a ``Runtime.evaluate`` by-value object could spoof.
     """
     from agent.redact import redact_sensitive_text
 
     if isinstance(value, str):
         return redact_sensitive_text(value, force=True)
-    if isinstance(value, list):
-        return [_redact_cdp_output(item) for item in value]
-    if isinstance(value, tuple):
-        return tuple(_redact_cdp_output(item) for item in value)
-    if isinstance(value, dict):
-        base64_flagged = value.get("base64Encoded") is True
+    if isinstance(value, (list, tuple)):
+        return type(value)(_redact_cdp_output(item) for item in value)
+    if not isinstance(value, dict):
+        return value
+    base64_flagged = value.get("base64Encoded") is True
 
-        def leaf(paths: tuple, key: str) -> bool:
-            return any(len(p) == 1 and p[0] == key for p in paths)
+    def leaf(paths: tuple, key: str) -> bool:
+        return any(len(p) == 1 and p[0] == key for p in paths)
 
-        def descend(paths: tuple, key: str) -> tuple:
-            return tuple(p[1:] for p in paths if len(p) > 1 and p[0] == key)
+    def descend(paths: tuple, key: str) -> tuple:
+        return tuple(p[1:] for p in paths if len(p) > 1 and p[0] == key)
+
+    redacted: Dict[str, Any] = {}
+    for key, item in value.items():
+        opaque = leaf(always_paths, key) or (leaf(flagged_paths, key) and base64_flagged)
+        if isinstance(item, str) and opaque:
+            redacted[key] = item
+        else:
+            redacted[key] = _redact_cdp_output(
+                item, always_paths=descend(always_paths, key), flagged_paths=descend(flagged_paths, key),
+            )
+    return redacted
 
-        redacted: Dict[str, Any] = {}
-        for key, item in value.items():
-            opaque = leaf(always_paths, key) or (leaf(flagged_paths, key) and base64_flagged)
-            if isinstance(item, str) and opaque:
-                redacted[key] = item
-            else:
-                redacted[key] = _redact_cdp_output(
-                    item,
-                    always_paths=descend(always_paths, key),
-                    flagged_paths=descend(flagged_paths, key),
-                )
-        return redacted
-    return value
 
 # ``websockets`` is a direct dependency; wrap so a stale env yields a clean error.
 try:
@@ -117,13 +108,11 @@ def _run_async(coro):
         loop = asyncio.get_running_loop()
     except RuntimeError:
         loop = None
-
     if loop and loop.is_running():
         import concurrent.futures
 
         with concurrent.futures.ThreadPoolExecutor(max_workers=1) as pool:
-            future = pool.submit(asyncio.run, coro)
-            return future.result()
+            return pool.submit(asyncio.run, coro).result()
     return asyncio.run(coro)
 
 
@@ -163,30 +152,25 @@ _METHOD_PARAM_GUARDS = {
 }
 
 
-def _browser_cdp_private_guard(
-    *,
-    task_id: str,
-    method: str,
-    params: Dict[str, Any],
-) -> Optional[str]:
+def _browser_cdp_private_guard(*, task_id: str, method: str, params: Dict[str, Any]) -> Optional[str]:
     """Apply the browser SSRF/private-page guard to raw CDP calls.
 
     Raw CDP shares the cloud/private-network boundary of ``browser_snapshot`` /
     ``browser_console`` / ``browser_eval`` and must not become their bypass.
+    Guard probes are best-effort; a probe failure never breaks local/custom CDP
+    workflows.
     """
     try:
         from tools import browser_tool as bt  # type: ignore[import-not-found]
 
         if not bt._eval_ssrf_guard_active(task_id):  # type: ignore[attr-defined]
             return None
-
         guard = _METHOD_PARAM_GUARDS.get(method)
         if guard is not None:
             probe, template = guard
             literal = probe(bt, params or {})
             if literal:
                 return _blocked(template.format(literal), method)
-
         if method not in _CDP_PRIVATE_PAGE_ALLOWED_METHODS:
             blocked_url = bt._current_page_private_url(task_id)  # type: ignore[attr-defined]
             if blocked_url:
@@ -197,17 +181,12 @@ def _browser_cdp_private_guard(
                     method,
                 )
     except Exception as exc:  # noqa: BLE001
-        # Guard probes are best-effort; never break local/custom CDP workflows.
         logger.debug("browser_cdp: private-page guard probe failed: %s", exc)
     return None
 
 
 async def _cdp_call(
-    ws_url: str,
-    method: str,
-    params: Dict[str, Any],
-    target_id: Optional[str],
-    timeout: float,
+    ws_url: str, method: str, params: Dict[str, Any], target_id: Optional[str], timeout: float,
 ) -> Dict[str, Any]:
     """Make a single CDP call, optionally attaching to a target first.
 
@@ -232,22 +211,18 @@ async def _cdp_call(
             next_id += 1
             await ws.send(json.dumps({"id": call_id, **req}))
             deadline = asyncio.get_running_loop().time() + timeout
-            while True:
+            while True:  # ignore events / out-of-order responses
                 remaining = deadline - asyncio.get_running_loop().time()
                 if remaining <= 0:
                     raise TimeoutError(f"Timed out {what}")
                 msg = json.loads(await asyncio.wait_for(ws.recv(), timeout=remaining))
                 if msg.get("id") == call_id:
                     return msg
-                # Ignore events / out-of-order responses
 
         session_id: Optional[str] = None
         if target_id:
             msg = await _send(
-                {
-                    "method": "Target.attachToTarget",
-                    "params": {"targetId": target_id, "flatten": True},
-                },
+                {"method": "Target.attachToTarget", "params": {"targetId": target_id, "flatten": True}},
                 f"attaching to target {target_id}",
             )
             if "error" in msg:
@@ -266,11 +241,7 @@ async def _cdp_call(
 
 
 def _browser_cdp_via_supervisor(
-    task_id: str,
-    frame_id: str,
-    method: str,
-    params: Optional[Dict[str, Any]],
-    timeout: float,
+    task_id: str, frame_id: str, method: str, params: Optional[Dict[str, Any]], timeout: float,
 ) -> str:
     """Route a CDP call through the live supervisor session for an OOPIF frame."""
     try:
@@ -291,11 +262,9 @@ def _browser_cdp_via_supervisor(
             f"frame_tree with frame_ids you can pass here."
         )
 
-    snap = supervisor.snapshot()
-    tree = snap.frame_tree
+    tree = supervisor.snapshot().frame_tree
     frame_info: Optional[Dict[str, Any]] = next(
-        (f for f in [tree.get("top"), *(tree.get("children") or [])]
-         if f and f.get("frame_id") == frame_id),
+        (f for f in [tree.get("top"), *(tree.get("children") or [])] if f and f.get("frame_id") == frame_id),
         None,
     )
     if frame_info is None:
@@ -304,7 +273,6 @@ def _browser_cdp_via_supervisor(
             raw = supervisor._frames.get(frame_id)  # type: ignore[attr-defined]
         if raw is not None:
             frame_info = raw.to_dict()
-
     if frame_info is None:
         return tool_error(
             f"frame_id {frame_id!r} not found in supervisor state. "
@@ -325,10 +293,7 @@ def _browser_cdp_via_supervisor(
 
     loop = supervisor._loop  # type: ignore[attr-defined]
     if loop is None or not loop.is_running():
-        return tool_error(
-            "CDP supervisor loop is not running. Try reconnecting with "
-            "/browser connect."
-        )
+        return tool_error("CDP supervisor loop is not running. Try reconnecting with /browser connect.")
 
     try:
         from agent.async_utils import safe_schedule_threadsafe
@@ -337,25 +302,20 @@ def _browser_cdp_via_supervisor(
             loop,
         )
         if fut is None:
-            return tool_error(
-                "CDP call via supervisor failed: loop unavailable",
-                cdp_docs=CDP_DOCS_URL,
-            )
+            return tool_error("CDP call via supervisor failed: loop unavailable", cdp_docs=CDP_DOCS_URL)
         result_msg = fut.result(timeout=timeout + 2)
     except Exception as exc:
         return tool_error(
-            f"CDP call via supervisor failed: {type(exc).__name__}: {exc}",
-            cdp_docs=CDP_DOCS_URL,
+            f"CDP call via supervisor failed: {type(exc).__name__}: {exc}", cdp_docs=CDP_DOCS_URL,
         )
 
-    payload: Dict[str, Any] = {
+    return json.dumps({
         "success": True,
         "method": method,
         "frame_id": frame_id,
         "session_id": child_sid,
         "result": result_msg.get("result", {}),
-    }
-    return json.dumps(payload, ensure_ascii=False)
+    }, ensure_ascii=False)
 
 
 def browser_cdp(
@@ -372,40 +332,26 @@ def browser_cdp(
     (OOPIF from ``browser_snapshot.frame_tree``) routes through the supervisor's
     live WebSocket instead — the only reliable way to evaluate inside an iframe
     on backends where fresh per-call connections hit signed-URL expiry
-    (Browserbase). Returns JSON ``{"success": True, "method", "result"}`` or
-    ``{"error": ...}``.
+    (Browserbase). Both paths share the same private-page/SSRF guard. Returns
+    JSON ``{"success": True, "method", "result"}`` or ``{"error": ...}``.
     """
     effective_task_id = task_id or "default"
 
     if frame_id:
-        # Same private-page/SSRF boundary as the stateless path below.
-        blocked = _browser_cdp_private_guard(
-            task_id=effective_task_id,
-            method=method,
-            params=params or {},
-        )
+        blocked = _browser_cdp_private_guard(task_id=effective_task_id, method=method, params=params or {})
         if blocked:
             return blocked
         return _browser_cdp_via_supervisor(
-            task_id=effective_task_id,
-            frame_id=frame_id,
-            method=method,
-            params=params,
-            timeout=timeout,
+            task_id=effective_task_id, frame_id=frame_id, method=method, params=params, timeout=timeout,
         )
 
     if not method or not isinstance(method, str):
-        return tool_error(
-            "'method' is required (e.g. 'Target.getTargets')",
-            cdp_docs=CDP_DOCS_URL,
-        )
-
+        return tool_error("'method' is required (e.g. 'Target.getTargets')", cdp_docs=CDP_DOCS_URL)
     if not _WS_AVAILABLE:
         return tool_error(
             "The 'websockets' Python package is required but not installed. "
             "Install it with: pip install websockets"
         )
-
     endpoint = _resolve_cdp_endpoint()
     if not endpoint:
         return tool_error(
@@ -415,7 +361,6 @@ def browser_cdp(
             "and does not expose CDP.",
             cdp_docs=CDP_DOCS_URL,
         )
-
     if not endpoint.startswith(("ws://", "wss://")):
         return tool_error(
             f"CDP endpoint is not a WebSocket URL: {endpoint!r}. "
@@ -423,18 +368,11 @@ def browser_cdp(
             "resolver should have rewritten this. Check that a Chromium-family "
             "browser is actually listening on the debug port."
         )
-
     call_params: Dict[str, Any] = params or {}
     if not isinstance(call_params, dict):
-        return tool_error(
-            f"'params' must be an object/dict, got {type(call_params).__name__}"
-        )
+        return tool_error(f"'params' must be an object/dict, got {type(call_params).__name__}")
 
-    blocked = _browser_cdp_private_guard(
-        task_id=effective_task_id,
-        method=method,
-        params=call_params,
-    )
+    blocked = _browser_cdp_private_guard(task_id=effective_task_id, method=method, params=call_params)
     if blocked:
         return blocked
 
@@ -445,14 +383,9 @@ def browser_cdp(
     safe_timeout = max(1.0, min(safe_timeout, 300.0))
 
     try:
-        result = _run_async(
-            _cdp_call(endpoint, method, call_params, target_id, safe_timeout)
-        )
+        result = _run_async(_cdp_call(endpoint, method, call_params, target_id, safe_timeout))
     except asyncio.TimeoutError as exc:
-        return tool_error(
-            f"CDP call timed out after {safe_timeout}s: {exc}",
-            method=method,
-        )
+        return tool_error(f"CDP call timed out after {safe_timeout}s: {exc}", method=method)
     except (TimeoutError, RuntimeError) as exc:
         return tool_error(str(exc), method=method)
     except WebSocketException as exc:
@@ -463,10 +396,7 @@ def browser_cdp(
         )
     except Exception as exc:  # pragma: no cover — unexpected
         logger.exception("browser_cdp unexpected error")
-        return tool_error(
-            f"Unexpected error: {type(exc).__name__}: {exc}",
-            method=method,
-        )
+        return tool_error(f"Unexpected error: {type(exc).__name__}: {exc}", method=method)
 
     payload: Dict[str, Any] = {
         "success": True,
@@ -586,6 +516,8 @@ def _browser_cdp_check() -> bool:
     Camofox (REST-only), default local agent-browser (hidden CDP port) and cloud
     providers whose per-session ``cdp_url`` isn't surfaced are gated out. Thin
     wrapper so ``registry.register`` stays a top-level statement (AST scan).
+    Raw (no-I/O) gate: check_fns run at every startup; resolving the endpoint
+    over HTTP here would block launch on a stale endpoint.
     """
     try:
         from tools.browser_tool import (  # type: ignore[import-not-found]
@@ -595,11 +527,7 @@ def _browser_cdp_check() -> bool:
     except ImportError as exc:  # pragma: no cover — defensive
         logger.debug("browser_cdp check: browser_tool import failed: %s", exc)
         return False
-    if not check_browser_requirements():
-        return False
-    # Raw (no-I/O) gate: check_fns run at every startup; resolving the
-    # endpoint over HTTP here would block launch on a stale endpoint.
-    return bool(_get_cdp_override_raw())
+    return bool(check_browser_requirements() and _get_cdp_override_raw())
 
 
 registry.register(
diff --git a/tools/browser_dialog_tool.py b/tools/browser_dialog_tool.py
index c77d48201e..b1e3d7a8c5 100644
--- a/tools/browser_dialog_tool.py
+++ b/tools/browser_dialog_tool.py
@@ -80,31 +80,18 @@ def browser_dialog(
     """Respond to a pending dialog on the active task's CDP supervisor."""
     supervisor = SUPERVISOR_REGISTRY.get(task_id or "default")
     if supervisor is None:
-        return json.dumps(
-            {
-                "success": False,
-                "error": (
-                    "No CDP supervisor is attached to this task. Either the "
-                    "browser backend doesn't expose CDP (Camofox, default "
-                    "Playwright) or no browser session has been started yet. "
-                    "Call browser_navigate or /browser connect first."
-                ),
-            }
-        )
-
-    result = supervisor.respond_to_dialog(
-        action=action,
-        prompt_text=prompt_text,
-        dialog_id=dialog_id,
-    )
+        return json.dumps({
+            "success": False,
+            "error": (
+                "No CDP supervisor is attached to this task. Either the "
+                "browser backend doesn't expose CDP (Camofox, default "
+                "Playwright) or no browser session has been started yet. "
+                "Call browser_navigate or /browser connect first."
+            ),
+        })
+    result = supervisor.respond_to_dialog(action=action, prompt_text=prompt_text, dialog_id=dialog_id)
     if result.get("ok"):
-        return json.dumps(
-            {
-                "success": True,
-                "action": action,
-                "dialog": result.get("dialog", {}),
-            }
-        )
+        return json.dumps({"success": True, "action": action, "dialog": result.get("dialog", {})})
     return json.dumps({"success": False, "error": result.get("error", "unknown error")})
 
 
diff --git a/tools/browser_extension_router.py b/tools/browser_extension_router.py
index c84e865513..cdf5ac7eab 100644
--- a/tools/browser_extension_router.py
+++ b/tools/browser_extension_router.py
@@ -51,10 +51,7 @@ def extension_controller_available(action: str) -> bool:
     consults the process-local broker directly and fails closed on any gap.
     """
     try:
-        from gateway.browser_control_broker import (
-            browser_control_enabled,
-            get_browser_control_broker,
-        )
+        from gateway.browser_control_broker import browser_control_enabled, get_browser_control_broker
 
         if not browser_control_enabled():
             return False
@@ -63,17 +60,11 @@ def extension_controller_available(action: str) -> bool:
             return False
         broker = get_browser_control_broker()
         scope = broker.scope_for_session(
-            session_id=session_id,
-            principal_id=principal_id,
-            transport_family=transport_family,
+            session_id=session_id, principal_id=principal_id, transport_family=transport_family,
         )
         return scope is not None and broker.select(scope, action) is not None
     except Exception:
-        logger.debug(
-            "browser extension availability check failed for %s",
-            action,
-            exc_info=True,
-        )
+        logger.debug("browser extension availability check failed for %s", action, exc_info=True)
         return False
 
 
@@ -97,17 +88,11 @@ def route_browser_tool(
     called exactly once when the feature is off or no server-bound identity
     exists; once a controller is selected its result/exception is final.
     """
-    if not enabled:
-        return fallback()
-
-    if not str(principal_id or "").strip() or not str(transport_family or "").strip():
+    if not enabled or not str(principal_id or "").strip() or not str(transport_family or "").strip():
         return fallback()
 
     identity = dict(
-        session_id=session_id,
-        task_id=task_id,
-        principal_id=principal_id,
-        transport_family=transport_family,
+        session_id=session_id, task_id=task_id, principal_id=principal_id, transport_family=transport_family,
     )
     scope = broker.scope_for_session(**identity)
     if scope is None:
@@ -117,25 +102,16 @@ def route_browser_tool(
         lane_bound = getattr(broker, "lane_registered", None)
         if callable(lane_bound) and not lane_bound(**identity):
             return fallback()
-        raise _controller_unavailable(
-            f"bound browser controller unavailable for {action}"
-        )
+        raise _controller_unavailable(f"bound browser controller unavailable for {action}")
 
-    controller = broker.select(scope, action)
-    if controller is None:
-        raise _controller_unavailable(
-            f"bound browser controller cannot execute {action}"
-        )
+    if broker.select(scope, action) is None:
+        raise _controller_unavailable(f"bound browser controller cannot execute {action}")
 
     # Controller is authoritative: never retry the legacy backend. Registry
     # handlers must return a string; keep string results byte-identical and
     # serialize decoded JSON values at this boundary.
-    result = broker.dispatch(
-        scope, action=action, arguments=args, tool_call_id=tool_call_id
-    )
-    if isinstance(result, str):
-        return result
-    return json.dumps(result, ensure_ascii=False)
+    result = broker.dispatch(scope, action=action, arguments=args, tool_call_id=tool_call_id)
+    return result if isinstance(result, str) else json.dumps(result, ensure_ascii=False)
 
 
 def current_tool_call_id() -> str:
@@ -164,23 +140,13 @@ def routed_browser_handler(
     Feature off (or gateway unimportable) ⇒ the legacy handler runs unchanged.
     """
     try:
-        from gateway.browser_control_broker import (
-            browser_control_enabled,
-            get_browser_control_broker,
-        )
+        from gateway.browser_control_broker import browser_control_enabled, get_browser_control_broker
     except Exception as exc:  # pragma: no cover - defensive, gateway always present
-        logger.debug(
-            "browser extension router unavailable (%s); using legacy backend",
-            exc,
-        )
+        logger.debug("browser extension router unavailable (%s); using legacy backend", exc)
         return fallback()
-
     if not browser_control_enabled():
         return fallback()
 
-    if tool_call_id is None:
-        tool_call_id = current_tool_call_id()
-
     try:
         env_session, env_principal, env_transport = _bound_identity()
     except Exception:
@@ -196,5 +162,5 @@ def routed_browser_handler(
         task_id=task_id,
         principal_id=principal_id or env_principal,
         transport_family=transport_family or env_transport,
-        tool_call_id=tool_call_id,
+        tool_call_id=current_tool_call_id() if tool_call_id is None else tool_call_id,
     )
diff --git a/tools/browser_lightpanda.py b/tools/browser_lightpanda.py
index 9dc7d4649b..ca98d2dadb 100644
--- a/tools/browser_lightpanda.py
+++ b/tools/browser_lightpanda.py
@@ -25,8 +25,7 @@ logger = logging.getLogger(__name__)
 
 LIGHTPANDA_INSTALL_URL = "https://lightpanda.io/docs/run-locally/installation/one-liner"
 LIGHTPANDA_INSTALL_HINT = (
-    f"Install Lightpanda from {LIGHTPANDA_INSTALL_URL} and make sure "
-    "`lightpanda` is on PATH"
+    f"Install Lightpanda from {LIGHTPANDA_INSTALL_URL} and make sure " "`lightpanda` is on PATH"
 )
 
 _READY_TIMEOUT_S = 10.0
@@ -57,8 +56,7 @@ class LightpandaServer:
 def _home_candidates() -> list:
     home = Path.home()
     candidates = [
-        home / ".lightpanda" / "lightpanda",
-        home / ".local" / "bin" / "lightpanda",
+        home / ".lightpanda" / "lightpanda", home / ".local" / "bin" / "lightpanda"
     ]
     try:
         from hermes_constants import get_hermes_home
@@ -285,8 +283,7 @@ def launch_lightpanda(
     with _servers_lock:
         _servers[session_name] = server
     logger.info(
-        "Started lightpanda serve (pid %s, port %s) for session %s",
-        proc.pid, port, session_name,
+        "Started lightpanda serve (pid %s, port %s) for session %s", proc.pid, port, session_name
     )
     return server, None
 
diff --git a/tools/browser_supervisor.py b/tools/browser_supervisor.py
index 5db78eda38..da646199fa 100644
--- a/tools/browser_supervisor.py
+++ b/tools/browser_supervisor.py
@@ -57,12 +57,9 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger(__name__)
 
-# Ring buffer of recent console-level events.
-CONSOLE_HISTORY_MAX = 50
-
 
 def _redact_cdp_error_text(exc: object) -> str:
-    """Redact CDP endpoint credentials from an exception's string form.
+    """Redact CDP endpoint credentials from an exception's (or URL's) string form.
 
     ``websockets`` bakes the raw target URL (``?token=`` / ``user:pass@``) into
     its exception messages. Every egress point that turns such an exception into
@@ -91,17 +88,8 @@ def _schedule(coro, loop, *, timeout: float):
     return fut.result(timeout=timeout)
 
 
-# ── Data model ────────────────────────────────────────────────────────────────
-
-
-@dataclass
-class ConsoleEvent:
-    """Ring buffer entry for console + exception traffic."""
-
-    ts: float
-    level: str  # "log" | "error" | "warning" | "exception"
-    text: str
-    url: Optional[str] = None
+def _err(exc: BaseException) -> Dict[str, Any]:
+    return {"ok": False, "error": f"{type(exc).__name__}: {exc}"}
 
 
 @dataclass(frozen=True)
@@ -111,7 +99,6 @@ class SupervisorSnapshot:
     pending_dialogs: Tuple[PendingDialog, ...]
     recent_dialogs: Tuple[DialogRecord, ...]
     frame_tree: Dict[str, Any]
-    console_errors: Tuple[ConsoleEvent, ...]
     active: bool  # False if supervisor is detached/stopped
     cdp_url: str
     task_id: str
@@ -163,7 +150,6 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
         self._pending_dialogs: Dict[str, PendingDialog] = {}
         self._recent_dialogs: List[DialogRecord] = []
         self._frames: Dict[str, FrameInfo] = {}
-        self._console_events: List[ConsoleEvent] = []
         self._active = False
 
         # Supervisor loop machinery — populated in start().
@@ -197,21 +183,14 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
         self._start_error = None
         self._stop_requested = False
         self._thread = threading.Thread(
-            target=self._thread_main,
-            name=f"cdp-supervisor-{self.task_id}",
-            daemon=True,
+            target=self._thread_main, name=f"cdp-supervisor-{self.task_id}", daemon=True,
         )
         self._thread.start()
         if not self._ready_event.wait(timeout=timeout):
             self.stop()
-            try:
-                from agent.redact import redact_cdp_url
-                _safe_url = redact_cdp_url(self.cdp_url)
-            except Exception:
-                _safe_url = "<cdp_url redacted>"
             raise TimeoutError(
                 f"CDP supervisor did not attach within {timeout}s "
-                f"(cdp_url={_safe_url[:80]}...)"
+                f"(cdp_url={_redact_cdp_error_text(self.cdp_url)[:80]}...)"
             )
         if self._start_error is not None:
             err = self._start_error
@@ -247,7 +226,6 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
                 pending_dialogs=tuple(self._pending_dialogs.values()),
                 recent_dialogs=tuple(self._recent_dialogs[-RECENT_DIALOGS_MAX:]),
                 frame_tree=self._build_frame_tree_locked(),
-                console_errors=tuple(self._console_events[-CONSOLE_HISTORY_MAX:]),
                 active=self._active,
                 cdp_url=self.cdp_url,
                 task_id=self.task_id,
@@ -309,7 +287,7 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
         except _LoopUnavailable as e:
             return {"ok": False, "error": str(e)}
         except Exception as e:
-            return {"ok": False, "error": f"{type(e).__name__}: {e}"}
+            return _err(e)
         return {"ok": True, "dialog": dialog.to_dict()}
 
     def evaluate_runtime(
@@ -362,13 +340,12 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
             # CDP's recursion guard with the protocol-level error ``Object
             # reference chain is too long``. Retry once with returnByValue=False
             # so Chrome returns the description string instead of failing.
-            if return_by_value and "reference chain is too long" in str(exc).lower():
-                try:
-                    response = _run_eval(False)
-                except Exception as exc2:
-                    return {"ok": False, "error": f"{type(exc2).__name__}: {exc2}"}
-            else:
-                return {"ok": False, "error": f"{type(exc).__name__}: {exc}"}
+            if not (return_by_value and "reference chain is too long" in str(exc).lower()):
+                return _err(exc)
+            try:
+                response = _run_eval(False)
+            except Exception as exc2:
+                return _err(exc2)
 
         # Response: {"result": {"result": {"type", "value", ...}, "exceptionDetails"?}}
         result_payload = response.get("result", {}) if isinstance(response, dict) else {}
@@ -382,7 +359,6 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
 
         result_obj = result_payload.get("result", {})
         result_type = result_obj.get("type", "undefined")
-
         if "value" in result_obj:
             value = result_obj["value"]
         elif result_type == "undefined":
@@ -391,7 +367,6 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
             # Non-serializable (functions, DOM nodes…) — give the model the
             # browser's description so it gets *something*.
             value = result_obj.get("description") or result_obj.get("unserializableValue")
-
         return {"ok": True, "result": value, "result_type": result_type}
 
     # ── Supervisor loop internals ────────────────────────────────────────────
@@ -404,13 +379,10 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
             asyncio.set_event_loop(loop)
             loop.run_until_complete(self._run())
         except BaseException as e:  # noqa: BLE001 — propagate via _start_error
-            if not self._ready_event.is_set():
-                self._start_error = e
-                self._ready_event.set()
-            else:
+            if not self._fail_start(e):
                 logger.warning("CDP supervisor %s crashed: %s", self.task_id, e)
         finally:
-            # Flush remaining tasks before closing the loop to avoid
+            # Cancel + flush remaining tasks before closing the loop to avoid
             # "Task was destroyed but it is pending" warnings.
             try:
                 pending = [t for t in asyncio.all_tasks(loop) if not t.done()]
@@ -418,19 +390,23 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
                     t.cancel()
                 if pending:
                     loop.run_until_complete(asyncio.gather(*pending, return_exceptions=True))
-            except Exception:
-                pass
-            try:
                 loop.close()
             except Exception:
                 pass
             with self._state_lock:
                 self._active = False
 
+    def _fail_start(self, e: BaseException) -> bool:
+        """Propagate ``e`` to ``start()`` if we never got ready; True if it was consumed."""
+        if self._ready_event.is_set():
+            return False
+        self._start_error = e
+        self._ready_event.set()
+        return True
+
     async def _close_ws(self) -> None:
         """Detach and close the current WebSocket, swallowing close errors."""
-        ws = self._ws
-        self._ws = None
+        ws, self._ws = self._ws, None
         if ws is not None:
             try:
                 await ws.close()
@@ -442,7 +418,8 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
 
         Browserbase tears down the CDP socket every time a short-lived client
         (e.g. agent-browser's per-command CDP client) disconnects, so on drop we
-        reset per-session ids, re-attach, and keep going.
+        reset per-session ids, re-attach, and keep going. A failure before the
+        first successful attach is fatal for ``start()``.
         """
         attempt = 0
         last_success_at = 0.0
@@ -451,15 +428,11 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
         while not self._stop_requested:
             try:
                 self._ws = await asyncio.wait_for(
-                    websockets.connect(self.cdp_url, max_size=50 * 1024 * 1024),
-                    timeout=10.0,
+                    websockets.connect(self.cdp_url, max_size=50 * 1024 * 1024), timeout=10.0,
                 )
             except Exception as e:
                 attempt += 1
-                if not self._ready_event.is_set():
-                    # Never connected once — fatal for start().
-                    self._start_error = e
-                    self._ready_event.set()
+                if self._fail_start(e):
                     return
                 logger.warning(
                     "CDP supervisor %s: connect failed (attempt %s): %s",
@@ -481,20 +454,14 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
                     self._active = True
                 last_success_at = time.time()
                 backoff = 0.5  # reset after a successful attach
-                if not self._ready_event.is_set():
-                    self._ready_event.set()
+                self._ready_event.set()
                 await reader_task
             except BaseException as e:
-                if not self._ready_event.is_set():
-                    # Never got to ready — propagate to start().
-                    self._start_error = e
-                    self._ready_event.set()
+                if self._fail_start(e):
                     raise
                 logger.warning(
                     "CDP supervisor %s: session dropped after %.1fs: %s",
-                    self.task_id,
-                    time.time() - last_success_at,
-                    _redact_cdp_error_text(e),
+                    self.task_id, time.time() - last_success_at, _redact_cdp_error_text(e),
                 )
             finally:
                 with self._state_lock:
@@ -505,22 +472,19 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
                         await reader_task
                     except (asyncio.CancelledError, Exception):
                         pass
-                for handle in list(self._dialog_watchdogs.values()):
+                for handle in self._dialog_watchdogs.values():
                     handle.cancel()
                 self._dialog_watchdogs.clear()
                 await self._close_ws()
 
             if self._stop_requested:
                 return
-
-            logger.debug(
-                "CDP supervisor %s: reconnecting in %.1fs...", self.task_id, backoff,
-            )
+            logger.debug("CDP supervisor %s: reconnecting in %.1fs...", self.task_id, backoff)
             await asyncio.sleep(backoff)
             backoff = min(backoff * 2, 10.0)
 
     async def _attach_initial_page(self) -> None:
-        """Find a page target, attach flattened session, enable domains, install dialog bridge."""
+        """Find (or create) a page target, attach flattened, enable domains, install dialog bridge."""
         resp = await self._cdp("Target.getTargets")
         targets = resp.get("result", {}).get("targetInfos", [])
         page_target = next((t for t in targets if t.get("type") == "page"), None)
@@ -529,11 +493,7 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
             target_id = created["result"]["targetId"]
         else:
             target_id = page_target["targetId"]
-
-        attach = await self._cdp(
-            "Target.attachToTarget",
-            {"targetId": target_id, "flatten": True},
-        )
+        attach = await self._cdp("Target.attachToTarget", {"targetId": target_id, "flatten": True})
         self._page_session_id = attach["result"]["sessionId"]
         await self._enable_page_domains(self._page_session_id, timeout=10.0)
         await self._install_dialog_bridge(self._page_session_id)
@@ -565,7 +525,7 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
             self._pending_calls.pop(call_id, None)
 
     async def _read_loop(self) -> None:
-        """Continuously dispatch incoming CDP frames."""
+        """Continuously dispatch incoming CDP frames (responses → futures, events → handlers)."""
         assert self._ws is not None
         try:
             async for raw in self._ws:
@@ -580,58 +540,22 @@ class CDPSupervisor(DialogSupervisionMixin, FrameTrackingMixin):
                     fut = self._pending_calls.pop(msg["id"], None)
                     if fut is not None and not fut.done():
                         if "error" in msg:
-                            fut.set_exception(
-                                RuntimeError(f"CDP error on id={msg['id']}: {msg['error']}")
-                            )
+                            fut.set_exception(RuntimeError(f"CDP error on id={msg['id']}: {msg['error']}"))
                         else:
                             fut.set_result(msg)
                 elif "method" in msg:
-                    await self._on_event(msg["method"], msg.get("params", {}), msg.get("sessionId"))
+                    handler = self._EVENT_HANDLERS.get(msg["method"])
+                    if handler is not None:
+                        result = handler(self, msg.get("params", {}), msg.get("sessionId"))
+                        if result is not None:
+                            await result
         except Exception as e:
             logger.debug("CDP read loop exited: %s", e)
 
-    # ── Event dispatch ──────────────────────────────────────────────────────
-
-    async def _on_event(
-        self, method: str, params: Dict[str, Any], session_id: Optional[str]
-    ) -> None:
-        handler = self._EVENT_HANDLERS.get(method)
-        if handler is None:
-            return
-        result = handler(self, params, session_id)
-        if result is not None:
-            await result
-
-    # ── Console / exception ring buffer ─────────────────────────────────────
-
-    def _on_console(self, params: Dict[str, Any], *, level_from: str) -> None:
-        if level_from == "exception":
-            details = params.get("exceptionDetails") or {}
-            text = str(details.get("text") or "")
-            url = details.get("url")
-            event = ConsoleEvent(ts=time.time(), level="exception", text=text, url=url)
-        else:
-            raw_level = str(params.get("type") or "log")
-            level = "error" if raw_level in {"error", "assert"} else (
-                "warning" if raw_level == "warning" else "log"
-            )
-            args = params.get("args") or []
-            parts: List[str] = []
-            for a in args[:4]:
-                if isinstance(a, dict):
-                    parts.append(str(a.get("value") or a.get("description") or ""))
-            event = ConsoleEvent(ts=time.time(), level=level, text=" ".join(parts))
-        with self._state_lock:
-            self._console_events.append(event)
-            self._console_events = _trim_ring(self._console_events, CONSOLE_HISTORY_MAX)
-
     # CDP event → handler(self, params, session_id). Async handlers return an
-    # awaitable that ``_on_event`` awaits; sync handlers return None.
+    # awaitable that ``_read_loop`` awaits; sync handlers return None.
     _EVENT_HANDLERS: Dict[str, Callable[..., Any]] = {
-        **DialogSupervisionMixin.EVENT_HANDLERS,
-        **FrameTrackingMixin.EVENT_HANDLERS,
-        "Runtime.consoleAPICalled": lambda self, p, _sid: self._on_console(p, level_from="api"),
-        "Runtime.exceptionThrown": lambda self, p, _sid: self._on_console(p, level_from="exception"),
+        **DialogSupervisionMixin.EVENT_HANDLERS, **FrameTrackingMixin.EVENT_HANDLERS
     }
 
 
@@ -664,27 +588,26 @@ class _SupervisorRegistry:
     ) -> CDPSupervisor:
         """Idempotently ensure a supervisor is running for ``(task_id, cdp_url)``.
 
-        An existing supervisor bound to a different ``cdp_url`` (or unhealthy)
-        is stopped and replaced.
+        An existing supervisor bound to a different ``cdp_url`` (or unhealthy:
+        dead thread / stopped loop) is stopped and replaced.
         """
         with self._lock:
             existing = self._by_task.get(task_id)
             if existing is not None:
-                if existing.cdp_url == cdp_url:
-                    thread_ok = existing._thread is not None and existing._thread.is_alive()
-                    loop_ok = existing._loop is not None and existing._loop.is_running()
-                    if thread_ok and loop_ok:
-                        return existing
-                # URL changed or unhealthy — tear down, fall through to re-create.
+                thread, loop = existing._thread, existing._loop
+                if (
+                    existing.cdp_url == cdp_url
+                    and thread is not None and thread.is_alive()
+                    and loop is not None and loop.is_running()
+                ):
+                    return existing
                 self._by_task.pop(task_id, None)
         if existing is not None:
             existing.stop()
 
         supervisor = CDPSupervisor(
-            task_id=task_id,
-            cdp_url=cdp_url,
-            dialog_policy=dialog_policy,
-            dialog_timeout_s=dialog_timeout_s,
+            task_id=task_id, cdp_url=cdp_url,
+            dialog_policy=dialog_policy, dialog_timeout_s=dialog_timeout_s,
         )
         supervisor.start(timeout=start_timeout)
         with self._lock:
@@ -706,9 +629,9 @@ class _SupervisorRegistry:
     def stop_all(self) -> None:
         """Stop every running supervisor. For shutdown / test teardown."""
         with self._lock:
-            items = list(self._by_task.items())
+            items = list(self._by_task.values())
             self._by_task.clear()
-        for _, supervisor in items:
+        for supervisor in items:
             supervisor.stop()
 
 
@@ -717,7 +640,6 @@ SUPERVISOR_REGISTRY = _SupervisorRegistry()
 
 __all__ = [
     "CDPSupervisor",
-    "ConsoleEvent",
     "DEFAULT_DIALOG_POLICY",
     "DEFAULT_DIALOG_TIMEOUT_S",
     "DIALOG_POLICY_AUTO_ACCEPT",
diff --git a/tools/browser_supervisor_dialogs.py b/tools/browser_supervisor_dialogs.py
index 017b3c3152..cb825c509b 100644
--- a/tools/browser_supervisor_dialogs.py
+++ b/tools/browser_supervisor_dialogs.py
@@ -22,7 +22,7 @@ import json
 import logging
 import time
 from dataclasses import dataclass
-from typing import Any, Callable, Coroutine, Dict, Optional
+from typing import Any, Callable, Dict, Optional
 from urllib.parse import parse_qs, urlparse
 
 # Logger-name parity with the origin module (records must look unchanged).
@@ -46,11 +46,9 @@ def _trim_ring(events: list, keep: int) -> list:
 DIALOG_POLICY_MUST_RESPOND = "must_respond"
 DIALOG_POLICY_AUTO_DISMISS = "auto_dismiss"
 DIALOG_POLICY_AUTO_ACCEPT = "auto_accept"
-
 _VALID_POLICIES = frozenset(
     {DIALOG_POLICY_MUST_RESPOND, DIALOG_POLICY_AUTO_DISMISS, DIALOG_POLICY_AUTO_ACCEPT}
 )
-
 DEFAULT_DIALOG_POLICY = DIALOG_POLICY_MUST_RESPOND
 DEFAULT_DIALOG_TIMEOUT_S = 300.0
 
@@ -64,7 +62,12 @@ RECENT_DIALOGS_MAX = 20
 DIALOG_BRIDGE_HOST = "hermes-dialog-bridge.invalid"
 DIALOG_BRIDGE_URL_PATTERN = f"http://{DIALOG_BRIDGE_HOST}/*"
 
-# Injected into every frame via Page.addScriptToEvaluateOnNewDocument.
+# Injected into every frame via Page.addScriptToEvaluateOnNewDocument. Uses a
+# sync GET with query params so the Fetch interceptor never parses a body; if
+# the bridge is unreachable it returns null so the page still sees *some*
+# behavior (the backend auto-dismisses). onbeforeunload is left native — it
+# can't be prompted synchronously without racing navigation; the native-dialog
+# fallback path still surfaces it in recent_dialogs.
 _DIALOG_BRIDGE_SCRIPT = r"""
 (() => {
   if (window.__hermesDialogBridgeInstalled) return;
@@ -73,8 +76,6 @@ _DIALOG_BRIDGE_SCRIPT = r"""
   function ask(kind, message, defaultPrompt) {
     try {
       const xhr = new XMLHttpRequest();
-      // Use GET with query params so we don't need to worry about request
-      // body encoding in the Fetch interceptor.
       const params = new URLSearchParams({
         kind: String(kind || ""),
         message: String(message == null ? "" : message),
@@ -83,9 +84,8 @@ _DIALOG_BRIDGE_SCRIPT = r"""
       xhr.open("GET", ENDPOINT + "?" + params.toString(), false);  // sync
       xhr.send(null);
       if (xhr.status !== 200) return null;
-      const body = xhr.responseText || "";
       let parsed;
-      try { parsed = JSON.parse(body); } catch (e) { return null; }
+      try { parsed = JSON.parse(xhr.responseText || ""); } catch (e) { return null; }
       if (kind === "alert") return undefined;
       if (kind === "confirm") return Boolean(parsed && parsed.accept);
       if (kind === "prompt") {
@@ -94,14 +94,9 @@ _DIALOG_BRIDGE_SCRIPT = r"""
       }
       return null;
     } catch (e) {
-      // If the bridge is unreachable, fall back to the native call so the
-      // page still sees *some* behavior (the backend will auto-dismiss).
       return null;
     }
   }
-  const realAlert   = window.alert;
-  const realConfirm = window.confirm;
-  const realPrompt  = window.prompt;
   window.alert   = function(message) { ask("alert",   message, ""); };
   window.confirm = function(message) {
     const r = ask("confirm", message, "");
@@ -111,10 +106,6 @@ _DIALOG_BRIDGE_SCRIPT = r"""
     const r = ask("prompt", message, def == null ? "" : def);
     return r === null ? null : String(r);
   };
-  // onbeforeunload — we can't really synchronously prompt the user from this
-  // event without racing navigation.  Leave native behavior for now; the
-  // supervisor's native-dialog fallback path still surfaces them in
-  // recent_dialogs.
 })();
 """
 
@@ -178,6 +169,14 @@ class DialogRecord:
 class DialogSupervisionMixin:
     """Dialog event handling for ``CDPSupervisor`` (all methods run on its loop)."""
 
+    async def _cdp_quiet(self, method: str, params: Dict[str, Any], *, session_id: Optional[str],
+                         timeout: float, what: str) -> None:
+        """Best-effort CDP call: failures are logged at debug and swallowed."""
+        try:
+            await self._cdp(method, params, session_id=session_id, timeout=timeout)
+        except Exception as e:
+            logger.debug("%s failed (%s): %s", method, what, e)
+
     async def _install_dialog_bridge(self, session_id: str) -> None:
         """Install the dialog-bridge init script + Fetch interceptor on a session.
 
@@ -185,110 +184,65 @@ class DialogSupervisionMixin:
         scoped to the bridge URL catches the XHRs, which surface as pending
         dialogs and are fulfilled when the agent responds. Idempotent at the CDP
         level (Chromium de-dupes identical add-script calls; Fetch.enable
-        replaces prior patterns).
+        replaces prior patterns). The final Runtime.evaluate injects into the
+        already-loaded document so existing pages pick up the override on reconnect.
         """
-        try:
-            await self._cdp(
-                "Page.addScriptToEvaluateOnNewDocument",
-                {"source": _DIALOG_BRIDGE_SCRIPT, "runImmediately": True},
-                session_id=session_id,
-                timeout=5.0,
-            )
-        except Exception as e:
-            logger.debug(
-                "dialog bridge: addScriptToEvaluateOnNewDocument failed on sid=%s: %s",
-                (session_id or "")[:16], e,
-            )
-        try:
-            await self._cdp(
-                "Fetch.enable",
-                {
-                    "patterns": [
-                        {
-                            "urlPattern": DIALOG_BRIDGE_URL_PATTERN,
-                            "requestStage": "Request",
-                        }
-                    ],
-                    "handleAuthRequests": False,
-                },
-                session_id=session_id,
-                timeout=5.0,
-            )
-        except Exception as e:
-            logger.debug(
-                "dialog bridge: Fetch.enable failed on sid=%s: %s",
-                (session_id or "")[:16], e,
-            )
-        # Best-effort inject into the already-loaded document so existing pages
-        # pick up the override on reconnect.
-        try:
-            await self._cdp(
-                "Runtime.evaluate",
-                {"expression": _DIALOG_BRIDGE_SCRIPT, "returnByValue": True},
-                session_id=session_id,
-                timeout=3.0,
-            )
-        except Exception:
-            pass
+        sid = (session_id or "")[:16]
+        await self._cdp_quiet(
+            "Page.addScriptToEvaluateOnNewDocument",
+            {"source": _DIALOG_BRIDGE_SCRIPT, "runImmediately": True},
+            session_id=session_id, timeout=5.0, what=f"dialog bridge sid={sid}",
+        )
+        await self._cdp_quiet(
+            "Fetch.enable",
+            {"patterns": [{"urlPattern": DIALOG_BRIDGE_URL_PATTERN, "requestStage": "Request"}],
+             "handleAuthRequests": False},
+            session_id=session_id, timeout=5.0, what=f"dialog bridge sid={sid}",
+        )
+        await self._cdp_quiet(
+            "Runtime.evaluate",
+            {"expression": _DIALOG_BRIDGE_SCRIPT, "returnByValue": True},
+            session_id=session_id, timeout=3.0, what=f"dialog bridge inject sid={sid}",
+        )
 
     # ── Capture ──────────────────────────────────────────────────────────────
 
-    async def _on_dialog_opening(
-        self, params: Dict[str, Any], session_id: Optional[str]
-    ) -> None:
-        dialog = self._new_dialog(
+    async def _on_dialog_opening(self, params: Dict[str, Any], session_id: Optional[str]) -> None:
+        self._admit_dialog(self._new_dialog(
             type=str(params.get("type") or ""),
             message=str(params.get("message") or ""),
             default_prompt=str(params.get("defaultPrompt") or ""),
             session_id=session_id,
             frame_id=params.get("frameId"),
-        )
-        self._admit_dialog(dialog, self._auto_handle_dialog)
+        ))
 
-    async def _on_fetch_paused(
-        self, params: Dict[str, Any], session_id: Optional[str]
-    ) -> None:
+    async def _on_fetch_paused(self, params: Dict[str, Any], session_id: Optional[str]) -> None:
         """Bridge XHR captured mid-flight — materialize as a pending dialog.
 
         The page's JS thread is blocked on the XHR until we Fetch.fulfillRequest
-        (from ``respond_to_dialog`` or the watchdog).
+        (from ``respond_to_dialog`` or the watchdog). Requests for other hosts
+        are forwarded unchanged so the page sees its own request.
         """
         url = str(params.get("request", {}).get("url") or "")
         request_id = params.get("requestId")
         if not request_id:
             return
         if DIALOG_BRIDGE_HOST not in url:
-            # Not ours — forward unchanged so the page sees its own request.
-            try:
-                await self._cdp(
-                    "Fetch.continueRequest", {"requestId": request_id},
-                    session_id=session_id, timeout=3.0,
-                )
-            except Exception:
-                pass
+            await self._cdp_quiet("Fetch.continueRequest", {"requestId": request_id},
+                                  session_id=session_id, timeout=3.0, what="passthrough")
             return
-
         q = parse_qs(urlparse(url).query)
-        dialog = self._new_dialog(
+        self._admit_dialog(self._new_dialog(
             type=q.get("kind", [""])[0] or "alert",
             message=q.get("message", [""])[0],
             default_prompt=q.get("default_prompt", [""])[0],
             session_id=session_id,
             frame_id=params.get("frameId"),
             bridge_request_id=str(request_id),
-        )
-        self._admit_dialog(dialog, self._fulfill_bridge_request)
+        ))
 
-    def _new_dialog(
-        self,
-        *,
-        type: str,
-        message: str,
-        default_prompt: str,
-        session_id: Optional[str],
-        frame_id: Optional[str],
-        bridge_request_id: Optional[str] = None,
-    ) -> PendingDialog:
+    def _new_dialog(self, *, type: str, message: str, default_prompt: str, session_id: Optional[str],
+                    frame_id: Optional[str], bridge_request_id: Optional[str] = None) -> PendingDialog:
         self._dialog_seq += 1
         return PendingDialog(
             id=f"d-{self._dialog_seq}",
@@ -301,12 +255,8 @@ class DialogSupervisionMixin:
             bridge_request_id=bridge_request_id,
         )
 
-    def _admit_dialog(
-        self,
-        dialog: PendingDialog,
-        responder: Callable[..., Coroutine[Any, Any, None]],
-    ) -> None:
-        """Apply the dialog policy: auto-respond via ``responder`` or queue + arm watchdog.
+    def _admit_dialog(self, dialog: PendingDialog) -> None:
+        """Apply the dialog policy: auto-respond, or queue + arm the watchdog.
 
         Auto policies archive FIRST (tagged ``auto_policy``) so the ``closed``
         event that follows our own response isn't re-archived as ``remote``.
@@ -316,61 +266,33 @@ class DialogSupervisionMixin:
             DIALOG_POLICY_AUTO_ACCEPT: (True, dialog.default_prompt),
         }.get(self.dialog_policy)
         if auto is not None:
-            accept, prompt_text = auto
             with self._state_lock:
                 self._archive_dialog_locked(dialog, "auto_policy")
-            asyncio.create_task(responder(dialog, accept=accept, prompt_text=prompt_text))
+            asyncio.create_task(self._respond_quiet(dialog, accept=auto[0], prompt_text=auto[1]))
             return
-        # must_respond → add to pending and arm watchdog.
         with self._state_lock:
             self._pending_dialogs[dialog.id] = dialog
-        loop = asyncio.get_running_loop()
-        handle = loop.call_later(
+        self._dialog_watchdogs[dialog.id] = asyncio.get_running_loop().call_later(
             self.dialog_timeout_s,
             lambda: asyncio.create_task(self._dialog_timeout_expired(dialog.id)),
         )
-        self._dialog_watchdogs[dialog.id] = handle
 
     # ── Responding ───────────────────────────────────────────────────────────
 
-    async def _respond(
-        self, dialog: PendingDialog, *, accept: bool, prompt_text: Optional[str]
-    ) -> None:
-        """Bridge-fulfill for XHR-captured dialogs, else native CDP. Raises on native CDP failure."""
+    async def _respond(self, dialog: PendingDialog, *, accept: bool, prompt_text: Optional[str]) -> None:
+        """Bridge-fulfill for XHR-captured dialogs, else native CDP.
+
+        Native path sends ``promptText`` only for prompt dialogs when
+        ``prompt_text`` is given, and raises on CDP failure; the bridge path
+        (Fetch.fulfillRequest so the page unblocks) swallows failures.
+        """
         if dialog.bridge_request_id:
-            await self._fulfill_bridge_request(dialog, accept=accept, prompt_text=prompt_text or "")
-        else:
-            await self._native_handle_dialog(dialog, accept=accept, prompt_text=prompt_text)
-
-    async def _native_handle_dialog(
-        self, dialog: PendingDialog, *, accept: bool, prompt_text: Optional[str]
-    ) -> None:
-        """Page.handleJavaScriptDialog; ``promptText`` sent only for prompt dialogs
-        when ``prompt_text`` is given. Raises on CDP failure."""
-        params: Dict[str, Any] = {"accept": accept}
-        if prompt_text is not None and dialog.type == "prompt":
-            params["promptText"] = prompt_text
-        await self._cdp(
-            "Page.handleJavaScriptDialog",
-            params,
-            session_id=dialog.cdp_session_id or None,
-            timeout=5.0,
-        )
-
-    async def _fulfill_bridge_request(
-        self, dialog: PendingDialog, *, accept: bool, prompt_text: str
-    ) -> None:
-        """Resolve a bridge XHR via Fetch.fulfillRequest so the page unblocks."""
-        if not dialog.bridge_request_id:
-            return
-        payload = {
-            "accept": bool(accept),
-            "prompt_text": prompt_text if dialog.type == "prompt" else "",
-            "dialog_id": dialog.id,
-        }
-        body = json.dumps(payload).encode()
-        try:
-            await self._cdp(
+            body = json.dumps({
+                "accept": bool(accept),
+                "prompt_text": (prompt_text or "") if dialog.type == "prompt" else "",
+                "dialog_id": dialog.id,
+            }).encode()
+            await self._cdp_quiet(
                 "Fetch.fulfillRequest",
                 {
                     "requestId": dialog.bridge_request_id,
@@ -381,24 +303,23 @@ class DialogSupervisionMixin:
                     ],
                     "body": base64.b64encode(body).decode(),
                 },
-                session_id=dialog.cdp_session_id or None,
-                timeout=5.0,
+                session_id=dialog.cdp_session_id or None, timeout=5.0, what=f"bridge fulfill {dialog.id}",
             )
-        except Exception as e:
-            logger.debug("bridge fulfill failed for %s: %s", dialog.id, e)
+            return
+        params: Dict[str, Any] = {"accept": accept}
+        if prompt_text is not None and dialog.type == "prompt":
+            params["promptText"] = prompt_text
+        await self._cdp("Page.handleJavaScriptDialog", params,
+                        session_id=dialog.cdp_session_id or None, timeout=5.0)
 
-    async def _auto_handle_dialog(
-        self, dialog: PendingDialog, *, accept: bool, prompt_text: str
-    ) -> None:
-        """Auto-policy response for a native dialog (already archived by the caller)."""
+    async def _respond_quiet(self, dialog: PendingDialog, *, accept: bool, prompt_text: Optional[str]) -> None:
+        """Auto-policy / watchdog response (already archived by the caller); failures logged only."""
         try:
-            await self._native_handle_dialog(dialog, accept=accept, prompt_text=prompt_text)
+            await self._respond(dialog, accept=accept, prompt_text=prompt_text)
         except Exception as e:
-            logger.debug("auto-handle CDP call failed for %s: %s", dialog.id, e)
+            logger.debug("auto response failed for %s: %s", dialog.id, e)
 
-    async def _handle_dialog_cdp(
-        self, dialog: PendingDialog, *, accept: bool, prompt_text: str
-    ) -> None:
+    async def _handle_dialog_cdp(self, dialog: PendingDialog, *, accept: bool, prompt_text: str) -> None:
         """Agent response path.
 
         The dialog is retired regardless of outcome — a CDP error usually means
@@ -416,19 +337,13 @@ class DialogSupervisionMixin:
             return
         logger.warning(
             "CDP supervisor %s: dialog %s (%s) auto-dismissed after %ss timeout",
-            self.task_id,
-            dialog_id,
-            dialog.type,
-            self.dialog_timeout_s,
+            self.task_id, dialog_id, dialog.type, self.dialog_timeout_s,
         )
-        try:
-            # Archive with watchdog tag BEFORE unblocking the page.
-            with self._state_lock:
-                if self._pending_dialogs.pop(dialog_id, None) is not None:
-                    self._archive_dialog_locked(dialog, "watchdog")
-            await self._respond(dialog, accept=False, prompt_text=None)
-        except Exception as e:
-            logger.debug("auto-dismiss failed for %s: %s", dialog_id, e)
+        # Archive with watchdog tag BEFORE unblocking the page.
+        with self._state_lock:
+            if self._pending_dialogs.pop(dialog_id, None) is not None:
+                self._archive_dialog_locked(dialog, "watchdog")
+        await self._respond_quiet(dialog, accept=False, prompt_text=None)
 
     # ── Bookkeeping ──────────────────────────────────────────────────────────
 
@@ -444,29 +359,20 @@ class DialogSupervisionMixin:
 
     def _archive_dialog_locked(self, dialog: PendingDialog, closed_by: str) -> None:
         """Move a pending dialog to the recent_dialogs ring buffer. Must hold state_lock."""
-        record = DialogRecord(
-            id=dialog.id,
-            type=dialog.type,
-            message=dialog.message,
-            opened_at=dialog.opened_at,
-            closed_at=time.time(),
-            closed_by=closed_by,
-            frame_id=dialog.frame_id,
-        )
-        self._recent_dialogs.append(record)
+        self._recent_dialogs.append(DialogRecord(
+            id=dialog.id, type=dialog.type, message=dialog.message, opened_at=dialog.opened_at,
+            closed_at=time.time(), closed_by=closed_by, frame_id=dialog.frame_id,
+        ))
         self._recent_dialogs = _trim_ring(self._recent_dialogs, RECENT_DIALOGS_MAX)
 
-    async def _on_dialog_closed(
-        self, params: Dict[str, Any], session_id: Optional[str]
-    ) -> None:
+    async def _on_dialog_closed(self, params: Dict[str, Any], session_id: Optional[str]) -> None:
         # ``Page.javascriptDialogClosed`` carries only ``result``/``userInput``, not
         # the message. Match by session id and clear the oldest native dialog on
         # it — the JS thread blocks while a dialog is up, so at most one is in
         # flight per session. Bridge dialogs resolve via Fetch.fulfillRequest.
         with self._state_lock:
             candidate_ids = [
-                d.id
-                for d in self._pending_dialogs.values()
+                d.id for d in self._pending_dialogs.values()
                 if d.cdp_session_id == session_id and d.bridge_request_id is None
             ]
         if candidate_ids:
diff --git a/tools/browser_supervisor_frames.py b/tools/browser_supervisor_frames.py
index 7d021be284..482c76d9c8 100644
--- a/tools/browser_supervisor_frames.py
+++ b/tools/browser_supervisor_frames.py
@@ -41,12 +41,7 @@ class FrameInfo:
     name: str = ""
 
     def to_dict(self) -> Dict[str, Any]:
-        d = {
-            "frame_id": self.frame_id,
-            "url": self.url,
-            "origin": self.origin,
-            "is_oopif": self.is_oopif,
-        }
+        d = {"frame_id": self.frame_id, "url": self.url, "origin": self.origin, "is_oopif": self.is_oopif}
         if self.cdp_session_id:
             d["session_id"] = self.cdp_session_id
         if self.parent_frame_id:
@@ -63,49 +58,36 @@ class FrameTrackingMixin:
         """Page.enable + Runtime.enable + nested auto-attach on one session."""
         await self._cdp("Page.enable", session_id=session_id, timeout=timeout)
         await self._cdp("Runtime.enable", session_id=session_id, timeout=timeout)
-        await self._cdp(
-            "Target.setAutoAttach", _AUTO_ATTACH_PARAMS,
-            session_id=session_id, timeout=timeout,
-        )
+        await self._cdp("Target.setAutoAttach", _AUTO_ATTACH_PARAMS, session_id=session_id, timeout=timeout)
 
-    def _on_frame_attached(
-        self, params: Dict[str, Any], session_id: Optional[str]
-    ) -> None:
+    def _on_frame_attached(self, params: Dict[str, Any], session_id: Optional[str]) -> None:
         frame_id = params.get("frameId")
         if not frame_id:
             return
         with self._state_lock:
             self._frames[frame_id] = FrameInfo(
-                frame_id=frame_id,
-                url="",
-                origin="",
-                parent_frame_id=params.get("parentFrameId"),
-                is_oopif=False,
-                cdp_session_id=session_id,
+                frame_id=frame_id, url="", origin="", parent_frame_id=params.get("parentFrameId"),
+                is_oopif=False, cdp_session_id=session_id,
             )
 
-    def _on_frame_navigated(
-        self, params: Dict[str, Any], session_id: Optional[str]
-    ) -> None:
+    def _on_frame_navigated(self, params: Dict[str, Any], session_id: Optional[str]) -> None:
         frame = params.get("frame") or {}
         frame_id = frame.get("id")
         if not frame_id:
             return
         with self._state_lock:
-            existing = self._frames.get(frame_id)
+            old = self._frames.get(frame_id)
             self._frames[frame_id] = FrameInfo(
                 frame_id=frame_id,
                 url=str(frame.get("url") or ""),
                 origin=str(frame.get("securityOrigin") or frame.get("origin") or ""),
-                parent_frame_id=frame.get("parentId") or (existing.parent_frame_id if existing else None),
-                is_oopif=bool(existing.is_oopif if existing else False),
-                cdp_session_id=existing.cdp_session_id if existing else session_id,
-                name=str(frame.get("name") or (existing.name if existing else "")),
+                parent_frame_id=frame.get("parentId") or (old.parent_frame_id if old else None),
+                is_oopif=bool(old.is_oopif if old else False),
+                cdp_session_id=old.cdp_session_id if old else session_id,
+                name=str(frame.get("name") or (old.name if old else "")),
             )
 
-    def _on_frame_detached(
-        self, params: Dict[str, Any], session_id: Optional[str]
-    ) -> None:
+    def _on_frame_detached(self, params: Dict[str, Any], session_id: Optional[str]) -> None:
         """Drop a frame only when it's truly gone.
 
         ``reason="swap"`` means the frame is migrating processes (e.g. promoted
@@ -115,14 +97,11 @@ class FrameTrackingMixin:
         alive, so keep it until Target.detached + a later frameDetached clear it.
         """
         frame_id = params.get("frameId")
-        if not frame_id:
-            return
-        reason = str(params.get("reason") or "remove").lower()
-        if reason == "swap":
+        if not frame_id or str(params.get("reason") or "remove").lower() == "swap":
             return
         with self._state_lock:
-            existing = self._frames.get(frame_id)
-            if existing and existing.is_oopif and existing.cdp_session_id:
+            old = self._frames.get(frame_id)
+            if old and old.is_oopif and old.cdp_session_id:
                 return
             self._frames.pop(frame_id, None)
 
@@ -132,22 +111,17 @@ class FrameTrackingMixin:
         target_type = info.get("type")
         if not sid or target_type not in {"iframe", "worker"}:
             return
-
-        # Record the frame with its OOPIF session id for interaction routing.
         if target_type == "iframe":
+            # Record the frame with its OOPIF session id for interaction routing;
+            # origin is filled by frameNavigated on the child session.
             target_id = info.get("targetId")
             with self._state_lock:
-                existing = self._frames.get(target_id)
+                old = self._frames.get(target_id)
                 self._frames[target_id] = FrameInfo(
-                    frame_id=target_id,
-                    url=str(info.get("url") or ""),
-                    origin="",  # filled by frameNavigated on the child session
-                    parent_frame_id=(existing.parent_frame_id if existing else None),
-                    is_oopif=True,
-                    cdp_session_id=sid,
-                    name=str(info.get("title") or (existing.name if existing else "")),
+                    frame_id=target_id, url=str(info.get("url") or ""), origin="",
+                    parent_frame_id=(old.parent_frame_id if old else None), is_oopif=True,
+                    cdp_session_id=sid, name=str(info.get("title") or (old.name if old else "")),
                 )
-
         # Enable child domains off-loop: awaiting the replies here would deadlock
         # because only the reader can resolve those Futures.
         asyncio.create_task(self._enable_child_domains(sid))
@@ -178,25 +152,21 @@ class FrameTrackingMixin:
                     self._frames[fid] = replace(frame, cdp_session_id=None)
 
     def _build_frame_tree_locked(self) -> Dict[str, Any]:
-        """Build the capped frame_tree payload. Must be called under state lock."""
-        frames = self._frames
-        empty = {"top": None, "children": [], "truncated": False}
-        if not frames:
-            return empty
+        """Build the capped frame_tree payload. Must be called under state lock.
 
-        # Top frame: one with no parent, preferring oopif=False.
+        Top frame = one with no parent, preferring oopif=False. BFS from it,
+        capped by FRAME_TREE_MAX_ENTRIES and FRAME_TREE_MAX_OOPIF_DEPTH for
+        OOPIF branches.
+        """
+        frames = self._frames
         tops = [f for f in frames.values() if not f.parent_frame_id]
         top = next((f for f in tops if not f.is_oopif), tops[0] if tops else None)
         if top is None:
-            return empty
+            return {"top": None, "children": [], "truncated": False}
 
-        # BFS from top, capped by FRAME_TREE_MAX_ENTRIES and
-        # FRAME_TREE_MAX_OOPIF_DEPTH for OOPIF branches.
         children: List[Dict[str, Any]] = []
         truncated = False
-        queue: List[Tuple[FrameInfo, int]] = [
-            (f, 1) for f in frames.values() if f.parent_frame_id == top.frame_id
-        ]
+        queue: List[Tuple[FrameInfo, int]] = [(f, 1) for f in frames.values() if f.parent_frame_id == top.frame_id]
         visited: set[str] = {top.frame_id}
         while queue and len(children) < FRAME_TREE_MAX_ENTRIES:
             frame, depth = queue.pop(0)
@@ -207,17 +177,9 @@ class FrameTrackingMixin:
                 truncated = True
                 continue
             children.append(frame.to_dict())
-            for f in frames.values():
-                if f.parent_frame_id == frame.frame_id and f.frame_id not in visited:
-                    queue.append((f, depth + 1))
-        if queue:
-            truncated = True
-
-        return {
-            "top": top.to_dict(),
-            "children": children,
-            "truncated": truncated,
-        }
+            queue.extend((f, depth + 1) for f in frames.values()
+                         if f.parent_frame_id == frame.frame_id and f.frame_id not in visited)
+        return {"top": top.to_dict(), "children": children, "truncated": truncated or bool(queue)}
 
     # CDP event → handler(self, params, session_id); merged into CDPSupervisor._EVENT_HANDLERS.
     EVENT_HANDLERS: Dict[str, Callable[..., Any]] = {
diff --git a/tools/browser_tool.py b/tools/browser_tool.py
index 736d321eb5..ef8a199070 100644
--- a/tools/browser_tool.py
+++ b/tools/browser_tool.py
@@ -19,34 +19,28 @@ real-profile CDP, snapshot store); their names are re-imported here so
 """
 
 import atexit
-import contextlib
-import functools
 import json
 import logging
 import os
-import signal
-import subprocess
-import shutil
+import subprocess  # noqa: F401  (tests patch tools.browser_tool.subprocess.Popen)
+import shutil  # noqa: F401  (tests patch tools.browser_tool.shutil.which)
 import sys
 import tempfile
 import threading
 import time
-from datetime import datetime, timezone
-from typing import Dict, Any, Optional, List, Tuple, Union
+from typing import Dict, Any, Optional, Union
 from pathlib import Path
 from agent.redact import redact_cdp_url
-from hermes_constants import (
+from hermes_constants import (  # noqa: F401  (test-patchable surface, read via origin by sibling modules)
     agent_browser_runnable,
     get_hermes_home,
     get_hermes_home_override,
     hermes_home_key,
     node_tool_runnable,
-    reset_hermes_home_override,
-    set_hermes_home_override,
 )
-from utils import env_int, is_truthy_value
+from utils import env_int, is_truthy_value  # noqa: F401  (read via origin by sibling modules)
 from hermes_cli.config import DEFAULT_CONFIG, cfg_get
-from hermes_cli._subprocess_compat import windows_hide_flags
+from hermes_cli._subprocess_compat import windows_hide_flags  # noqa: F401  (test-patchable; read via origin)
 
 
 def __getattr__(name: str):
@@ -76,6 +70,7 @@ def _lazy_call_llm(*args, **kwargs):
         fn = __getattr__("call_llm")
     return fn(*args, **kwargs)
 
+
 # Keys re-added to the agent-browser subprocess env AFTER credential stripping.
 # agent-browser is a Node process loading npm deps: a compromised transitive
 # dependency could read every Hermes secret from process.env, so only the
@@ -104,6 +99,7 @@ def _build_browser_env() -> dict:
             env[_key] = os.environ[_key]
     return env
 
+
 try:
     from tools.website_policy import check_website_access
 except Exception:
@@ -147,7 +143,7 @@ from plugins.browser.browser_use.provider import (  # noqa: F401
 from plugins.browser.firecrawl.provider import (  # noqa: F401
     FirecrawlBrowserProvider as FirecrawlProvider,
 )
-from tools.tool_backend_helpers import normalize_browser_cloud_provider
+from tools.tool_backend_helpers import normalize_browser_cloud_provider  # noqa: F401  (read via origin)
 # Camofox local anti-detection browser backend (optional).
 # When CAMOFOX_URL is set, all browser operations route through the
 # camofox REST API instead of the agent-browser CLI.
@@ -181,51 +177,26 @@ _SANE_PATH_DIRS = (
 _SANE_PATH = os.pathsep.join(_SANE_PATH_DIRS)
 
 
-@functools.lru_cache(maxsize=1)
-def _discover_homebrew_node_dirs() -> tuple[str, ...]:
-    """Find Homebrew versioned Node.js bin directories (e.g. node@20, node@24).
-
-    When Node is installed via ``brew install node@24`` and NOT linked into
-    /opt/homebrew/bin, agent-browser isn't discoverable on the default PATH.
-    This function finds those directories so they can be prepended.
-    """
-    dirs: list[str] = []
-    homebrew_opt = "/opt/homebrew/opt"
-    if not os.path.isdir(homebrew_opt):
-        return tuple(dirs)
-    try:
-        for entry in os.listdir(homebrew_opt):
-            if entry.startswith("node") and entry != "node":
-                bin_dir = os.path.join(homebrew_opt, entry, "bin")
-                if os.path.isdir(bin_dir):
-                    dirs.append(bin_dir)
-    except OSError:
-        pass
-    return tuple(dirs)
-
-
-def _browser_candidate_path_dirs() -> list[str]:
-    """Return ordered browser CLI PATH candidates shared by discovery and execution."""
-    hermes_home = get_hermes_home()
-    hermes_node_bin = str(hermes_home / "node" / "bin")
-    hermes_node_root = str(hermes_home / "node")
-    hermes_nm_bin = str(hermes_home / "node_modules" / ".bin")
-    return [hermes_node_bin, hermes_node_root, hermes_nm_bin, *list(_discover_homebrew_node_dirs()), *_SANE_PATH_DIRS]
-
-
-def _merge_browser_path(existing_path: str = "") -> str:
-    """Prepend browser-specific PATH fallbacks without reordering existing entries."""
-    path_parts = [p for p in (existing_path or "").split(os.pathsep) if p]
-    existing_parts = set(path_parts)
-    prefix_parts: list[str] = []
-
-    for part in _browser_candidate_path_dirs():
-        if not part or part in existing_parts or part in prefix_parts:
-            continue
-        if os.path.isdir(part):
-            prefix_parts.append(part)
-
-    return os.pathsep.join(prefix_parts + path_parts)
+from tools.browser_tool_install import (  # noqa: F401  (re-exported; tests patch tools.browser_tool.<name>)
+    _discover_homebrew_node_dirs,
+    _browser_candidate_path_dirs,
+    _merge_browser_path,
+    _browser_install_hint,
+    _is_npx_agent_browser_sentinel,
+    _requires_real_termux_browser_install,
+    _termux_browser_install_error,
+    _agent_browser_candidate_present,
+    _resolve_npx_bin,
+    _agent_browser_candidates,
+    _find_agent_browser,
+    warm_agent_browser_npx_cache,
+    _chromium_search_roots,
+    _chromium_installed,
+    _maybe_autoinstall_chromium,
+    _running_in_docker,
+    check_browser_requirements,
+    check_browser_vision_requirements,
+)
 
 # Throttle screenshot cleanup to avoid repeated full directory scans.
 _last_screenshot_cleanup_by_dir: dict[str, float] = {}
@@ -348,97 +319,30 @@ def _get_open_command_timeout(*, first_open: bool = False) -> int:
     return max(base, floor)
 
 
-def _needs_chromium_sandbox_bypass() -> bool:
-    """Return True when Chromium needs --no-sandbox to start reliably."""
-    if hasattr(os, "geteuid") and os.geteuid() == 0:
-        return True
-    if _running_in_docker():
-        return True
-    userns_restrict = "/proc/sys/kernel/apparmor_restrict_unprivileged_userns"
-    try:
-        with open(userns_restrict, encoding="utf-8") as f:
-            if f.read().strip() == "1":
-                return True
-    except OSError:
-        pass
-    return False
-
-
-def _apply_chromium_sandbox_args(browser_env: Dict[str, str]) -> None:
-    """Add required Chromium sandbox flags without overriding user settings."""
-    if (
-        "AGENT_BROWSER_ARGS" not in browser_env
-        and "AGENT_BROWSER_CHROME_FLAGS" not in browser_env
-        and _needs_chromium_sandbox_bypass()
-    ):
-        logger.debug(
-            "browser: sandbox bypass needed (root/docker/AppArmor userns) — "
-            "injecting --no-sandbox"
-        )
-        browser_env["AGENT_BROWSER_ARGS"] = "--no-sandbox,--disable-dev-shm-usage"
-
-
-def _read_command_output_files(stdout_path: str, stderr_path: str) -> tuple[str, str]:
-    """Best-effort read of agent-browser stdout/stderr temp files."""
-    stdout = stderr = ""
-    for path, slot in ((stdout_path, "stdout"), (stderr_path, "stderr")):
-        try:
-            with open(path, "r", encoding="utf-8") as f:
-                text = f.read().strip()
-        except OSError:
-            continue
-        if slot == "stdout":
-            stdout = text
-        else:
-            stderr = text
-    return stdout, stderr
-
-
-def _unlink_command_output_files(*paths: str) -> None:
-    for path in paths:
-        try:
-            os.unlink(path)
-        except OSError:
-            pass
-
-
-def _format_browser_timeout_error(
-    command: str,
-    timeout: int,
-    stdout: str,
-    stderr: str,
-) -> str:
-    """Build an actionable timeout message from captured daemon output."""
-    parts = [f"Command timed out after {timeout} seconds"]
-    detail = (stderr or stdout or "").strip()
-    if detail:
-        parts.append(detail[:1500])
-
-    combined = f"{stderr}\n{stdout}".lower()
-    hints: list[str] = []
-    if "sandbox" in combined:
-        hints.append(
-            "Chromium sandbox launch failed. Set AGENT_BROWSER_ARGS="
-            "'--no-sandbox,--disable-dev-shm-usage' in your environment, "
-            "or run: npx agent-browser install --with-deps"
-        )
-    elif command == "open" and _is_local_mode():
-        if _running_in_docker():
-            hints.append(
-                "The browser daemon may still be starting or Chromium may be "
-                "missing. Pull the latest image: "
-                "docker pull ghcr.io/nousresearch/hermes-agent:latest"
-            )
-        else:
-            hints.append(
-                "The browser daemon may still be starting, or Chromium may be "
-                "missing system libraries. Install/repair with: "
-                "npx agent-browser install --with-deps "
-                "(or: npx playwright install --with-deps chromium)"
-            )
-    if hints:
-        parts.extend(hints)
-    return "\n".join(parts)
+from tools.browser_tool_session import (  # noqa: F401  (re-exported; tests patch tools.browser_tool.<name>)
+    _needs_chromium_sandbox_bypass,
+    _apply_chromium_sandbox_args,
+    _read_command_output_files,
+    _unlink_command_output_files,
+    _format_browser_timeout_error,
+    _agent_browser_argv,
+    _prepare_session_socket_dir,
+    _agent_browser_command_env,
+    _popen_agent_browser,
+    _create_local_session,
+    _create_lightpanda_session,
+    _local_backend_process_dead,
+    _create_cdp_session,
+    _create_cloud_session_or_fallback,
+    _create_session_for_key,
+    _get_session_info,
+    _discard_timed_out_browser_session,
+    _read_browser_daemon_pid,
+    _browser_daemon_responsive,
+    _handle_browser_command_timeout,
+    _interpret_browser_command_output,
+    _run_browser_command,
+)
 
 
 def _get_vision_model() -> Optional[str]:
@@ -446,181 +350,14 @@ def _get_vision_model() -> Optional[str]:
     return os.getenv("AUXILIARY_VISION_MODEL", "").strip() or None
 
 
-def _resolve_cdp_override(cdp_url: str) -> str:
-    """Normalize a user-supplied CDP endpoint into a concrete websocket URL.
-
-    Full ``ws://.../devtools/browser/...`` endpoints pass through; HTTP
-    discovery roots and bare ``ws://host:port`` are resolved via
-    ``/json/version`` → ``webSocketDebuggerUrl`` (falls back to the raw value
-    with a warning if discovery fails).
-    """
-    raw = (cdp_url or "").strip()
-    if not raw:
-        return ""
-
-    lowered = raw.lower()
-    if "/devtools/browser/" in lowered:
-        return raw
-
-    discovery_url = raw
-    if lowered.startswith(("ws://", "wss://")):
-        if raw.count(":") == 2 and raw.rstrip("/").rsplit(":", 1)[-1].isdigit() and "/" not in raw.split(":", 2)[-1]:
-            discovery_url = ("http://" if lowered.startswith("ws://") else "https://") + raw.split("://", 1)[1]
-        else:
-            return raw
-
-    if discovery_url.lower().endswith("/json/version"):
-        version_url = discovery_url
-    else:
-        version_url = discovery_url.rstrip("/") + "/json/version"
-
-    try:
-        import requests  # lazy — shared module object, test patches still apply
-
-        response = requests.get(version_url, timeout=10)
-        response.raise_for_status()
-        payload = response.json()
-    except Exception as exc:
-        logger.warning(
-            "Failed to resolve CDP endpoint %s via %s: %s",
-            _sanitize_url_for_logs(raw),
-            _sanitize_url_for_logs(version_url),
-            _sanitize_url_for_logs(exc),
-        )
-        return raw
-
-    ws_url = str(payload.get("webSocketDebuggerUrl") or "").strip()
-    if ws_url:
-        logger.info(
-            "Resolved CDP endpoint %s -> %s",
-            _sanitize_url_for_logs(raw),
-            _sanitize_url_for_logs(ws_url),
-        )
-        return ws_url
-
-    logger.warning(
-        "CDP discovery at %s did not return webSocketDebuggerUrl; using raw endpoint",
-        _sanitize_url_for_logs(version_url),
-    )
-    return raw
-
-
-def _get_cdp_override_raw() -> str:
-    """Return the *configured* CDP override without any network I/O.
-
-    Precedence: ``BROWSER_CDP_URL`` env (live ``/browser connect`` override),
-    then ``browser.cdp_url`` in config.yaml. Callers that only need to know
-    *whether* an override exists (check_fn gates, ``_is_local_mode`` /
-    ``_is_local_backend``, ``hermes doctor``) MUST use this, not
-    :func:`_get_cdp_override`: that one does a 10s HTTP discovery, and a stale
-    ``cdp_url`` pointing at a dead Chrome would stall every startup's schema
-    build with no error — no side effects during schema build.
-    """
-    env_override = os.environ.get("BROWSER_CDP_URL", "").strip()
-    if env_override:
-        return env_override
-    return _browser_cfg(
-        "cdp_url", "", lambda v: str(v or "").strip(), "browser.cdp_url from config"
-    )
-
-
-def _get_cdp_override() -> str:
-    """Return the resolved CDP URL override, or "" (skips cloud AND local launch).
-
-    May perform an HTTP ``/json/version`` discovery request — only call on
-    paths about to *connect* (session creation, supervisor attach); pure
-    is-it-configured gates must use :func:`_get_cdp_override_raw`.
-    """
-    raw = _get_cdp_override_raw()
-    if not raw:
-        return ""
-    return _resolve_cdp_override(raw)
-
-
-def _get_dialog_policy_config() -> Tuple[str, float]:
-    """Read ``browser.dialog_policy`` + ``browser.dialog_timeout_s`` from config.
-
-    Returns a ``(policy, timeout_s)`` tuple, falling back to the supervisor's
-    defaults when keys are absent or invalid.
-    """
-    # Defer imports so browser_tool can be imported in minimal environments.
-    from tools.browser_supervisor import (
-        DEFAULT_DIALOG_POLICY,
-        DEFAULT_DIALOG_TIMEOUT_S,
-        _VALID_POLICIES,
-    )
-
-    try:
-        from hermes_cli.config import read_raw_config
-
-        cfg = read_raw_config()
-        browser_cfg = cfg.get("browser", {}) if isinstance(cfg, dict) else {}
-        if not isinstance(browser_cfg, dict):
-            return DEFAULT_DIALOG_POLICY, DEFAULT_DIALOG_TIMEOUT_S
-        policy = str(browser_cfg.get("dialog_policy") or DEFAULT_DIALOG_POLICY)
-        if policy not in _VALID_POLICIES:
-            logger.debug("Invalid browser.dialog_policy=%r; using default", policy)
-            policy = DEFAULT_DIALOG_POLICY
-        timeout_raw = browser_cfg.get("dialog_timeout_s")
-        try:
-            timeout_s = float(timeout_raw) if timeout_raw is not None else DEFAULT_DIALOG_TIMEOUT_S
-            if timeout_s <= 0:
-                timeout_s = DEFAULT_DIALOG_TIMEOUT_S
-        except (TypeError, ValueError):
-            timeout_s = DEFAULT_DIALOG_TIMEOUT_S
-        return policy, timeout_s
-    except Exception:
-        return DEFAULT_DIALOG_POLICY, DEFAULT_DIALOG_TIMEOUT_S
-
-
-def _ensure_cdp_supervisor(task_id: str) -> None:
-    """Start a CDP supervisor for ``task_id`` if an endpoint is reachable.
-
-    Idempotent (``SupervisorRegistry.get_or_start`` skips an existing
-    ``(task_id, cdp_url)`` and restarts on URL change), so safe on every
-    navigate / ``/browser connect``. URL precedence: the CDP override, then the
-    session's own ``cdp_url`` (cloud providers). Swallows all errors — a failed
-    attach must not break the session; snapshots just lack
-    ``pending_dialogs`` / ``frame_tree``.
-    """
-    cdp_url = _get_cdp_override()
-    if not cdp_url:
-        # Fallback: active session may carry a per-session CDP URL from a
-        # cloud provider (Browserbase sets this).
-        with _cleanup_lock:
-            session_info = _active_sessions.get(task_id, {})
-        maybe = str(session_info.get("cdp_url") or "")
-        if maybe:
-            cdp_url = _resolve_cdp_override(maybe)
-    if not cdp_url:
-        return
-    try:
-        from tools.browser_supervisor import SUPERVISOR_REGISTRY  # type: ignore[import-not-found]
-
-        policy, timeout_s = _get_dialog_policy_config()
-        SUPERVISOR_REGISTRY.get_or_start(
-            task_id=task_id,
-            cdp_url=cdp_url,
-            dialog_policy=policy,
-            dialog_timeout_s=timeout_s,
-        )
-    except Exception as exc:
-        logger.debug(
-            "CDP supervisor attach for task=%s failed (non-fatal): %s",
-            task_id,
-            exc,
-        )
-
-
-def _stop_cdp_supervisor(task_id: str) -> None:
-    """Stop the CDP supervisor for ``task_id`` if one exists. No-op otherwise."""
-    try:
-        from tools.browser_supervisor import SUPERVISOR_REGISTRY  # type: ignore[import-not-found]
-
-        SUPERVISOR_REGISTRY.stop(task_id)
-    except Exception as exc:
-        logger.debug("CDP supervisor stop for task=%s failed (non-fatal): %s", task_id, exc)
-
+from tools.browser_tool_cdp import (  # noqa: F401  (re-exported; tests patch tools.browser_tool.<name>)
+    _resolve_cdp_override,
+    _get_cdp_override_raw,
+    _get_cdp_override,
+    _get_dialog_policy_config,
+    _ensure_cdp_supervisor,
+    _stop_cdp_supervisor,
+)
 
 # ============================================================================
 # Cloud Provider Registry
@@ -660,190 +397,25 @@ _cached_browser_engine: Optional[str] = None
 _browser_engine_resolved = False
 
 
-def _is_legacy_provider_registry_overridden() -> bool:
-    """True when a test has patched ``_PROVIDER_REGISTRY`` to a custom value.
+from tools.browser_tool_cloud import (  # noqa: F401  (re-exported; tests patch tools.browser_tool.<name>)
+    _is_legacy_provider_registry_overridden,
+    _ensure_browser_plugins_loaded,
+    _get_cloud_provider,
+    _instantiate_explicit_cloud_provider,
+    _autodetect_cloud_provider,
+    _resolve_cloud_provider_uncached,
+    _is_local_mode,
+    _is_local_backend,
+    _get_browser_engine,
+    _is_headed_mode,
+    _should_inject_engine,
+    _auto_local_for_private_urls,
+    _use_real_profile,
+    _allow_private_urls,
+    _resolve_allow_private_urls,
+)
 
-    Each registered value is compared by identity against the canonical class
-    in ``_DEFAULT_PROVIDER_REGISTRY`` (extra keys count too); adding a built-in
-    provider only requires extending that default dict.
-    """
-    try:
-        for key, default_cls in _DEFAULT_PROVIDER_REGISTRY.items():
-            if _PROVIDER_REGISTRY.get(key) is not default_cls:
-                return True
-        # Extra keys not in the default registry → also an override.
-        return len(_PROVIDER_REGISTRY) != len(_DEFAULT_PROVIDER_REGISTRY)
-    except Exception:
-        return False
-
-
-def _ensure_browser_plugins_loaded() -> None:
-    """Idempotently trigger plugin discovery so the browser registry is populated.
-
-    ``model_tools`` normally does this as an import side effect, but
-    ``_get_cloud_provider`` is also reached from standalone scripts and test
-    harnesses that never import it; cheap on repeat calls.
-    """
-    try:
-        from hermes_cli.plugins import _ensure_plugins_discovered
-
-        _ensure_plugins_discovered()
-    except Exception as exc:
-        logger.debug("Browser plugin discovery failed (non-fatal): %s", exc)
-
-
-def _get_cloud_provider() -> Optional[CloudBrowserProvider]:
-    """Return the provider cached for the active Hermes profile."""
-    global _cached_cloud_provider, _cloud_provider_resolved
-    global _cached_cloud_provider_scope
-
-    scope = hermes_home_key()
-    with _cloud_provider_cache_lock:
-        # Tests and legacy reset paths clear the boolean. Treat that as a full
-        # reset even if a previous scoped resolution remains mirrored here.
-        if not _cloud_provider_resolved:
-            _cached_cloud_provider_scope = None
-            _cached_cloud_providers.clear()
-        while True:
-            before_generation = _browser_registry_generation(scope=scope)
-            cache_key = (scope, before_generation)
-            if cache_key in _cached_cloud_providers:
-                _cached_cloud_provider = _cached_cloud_providers[cache_key]
-                _cloud_provider_resolved = True
-                _cached_cloud_provider_scope = scope
-                return _cached_cloud_provider
-
-            _cached_cloud_provider = None
-            _cloud_provider_resolved = False
-            resolved = _resolve_cloud_provider_uncached()
-            after_generation = _browser_registry_generation(scope=scope)
-            if before_generation != after_generation:
-                # A force reload replaced/unloaded this profile's provider
-                # while resolution was in progress. Discard the stale result
-                # and resolve against the new registry generation.
-                continue
-            if _cloud_provider_resolved:
-                _cached_cloud_provider_scope = scope
-                for stale_key in [
-                    key for key in _cached_cloud_providers if key[0] == scope
-                ]:
-                    _cached_cloud_providers.pop(stale_key, None)
-                _cached_cloud_providers[cache_key] = resolved
-            return resolved
-
-
-def _instantiate_explicit_cloud_provider(provider_key: str) -> Optional[CloudBrowserProvider]:
-    """Build the provider named by ``browser.cloud_provider``.
-
-    Test fixtures that patch ``_PROVIDER_REGISTRY`` drive the legacy dict;
-    otherwise the plugin registry is consulted (after idempotent discovery).
-    Strict selection: a stored-but-unregistered name raises ``ValueError``
-    (never a silent reroute to auto-detect). Any other instantiation error is
-    logged and yields None so the next call retries.
-    """
-    try:
-        if _is_legacy_provider_registry_overridden():
-            factory = _PROVIDER_REGISTRY.get(provider_key)
-            resolved = factory() if factory is not None else None
-        else:
-            _ensure_browser_plugins_loaded()
-            resolved = _registry_get_browser_provider(provider_key)
-        if resolved is None:
-            from tools.tool_backend_helpers import selection_error
-
-            raise ValueError(selection_error(
-                "browser",
-                f"'{provider_key}'",
-                "no registered browser plugin has that name (install "
-                "the corresponding plugin or fix the config key "
-                "spelling)",
-            ))
-        return resolved
-    except ValueError:
-        raise
-    except Exception:
-        logger.warning(
-            "Failed to instantiate explicit cloud_provider %r; will retry on next call",
-            provider_key,
-            exc_info=True,
-        )
-        return None
-
-
-def _autodetect_cloud_provider() -> Optional[CloudBrowserProvider]:
-    """Auto-detect: Browser Use (managed Nous gateway or API key), then Browserbase.
-
-    Uses the legacy class names bound on this module so tests that
-    ``monkeypatch.setattr(browser_tool, "BrowserUseProvider", ...)`` keep
-    driving this branch. Third-party plugins are intentionally NOT reachable
-    from auto-detect — only via explicit ``browser.cloud_provider: <name>``.
-    Never raises (a failure must not poison the cache).
-    """
-    try:
-        for cls in (BrowserUseProvider, BrowserbaseProvider):
-            fallback_provider = cls()
-            if fallback_provider.is_configured():
-                return fallback_provider
-    except Exception:  # pragma: no cover - defensive: never poison cache
-        logger.debug("Cloud provider auto-detect failed", exc_info=True)
-    return None
-
-
-def _resolve_cloud_provider_uncached() -> Optional[CloudBrowserProvider]:
-    """Return the configured cloud browser provider, or None for local mode.
-
-    Reads ``browser.cloud_provider`` and pins the result in the cache only when
-    it is definitive (explicit ``local``/``camofox``, or a resolved provider).
-    Explicit selection routes through :mod:`agent.browser_registry` so
-    third-party plugins participate; auto-detect (only when no selection was
-    ever written) walks Browser Use then Browserbase. A transient None
-    (unreadable config, missing credentials) is NOT cached so it can self-heal.
-    """
-    global _cached_cloud_provider, _cloud_provider_resolved
-
-    resolved: Optional[CloudBrowserProvider] = None
-    provider_key = None
-    try:
-        from hermes_cli.config import read_raw_config
-        browser_cfg = read_raw_config().get("browser", {})
-        if isinstance(browser_cfg, dict) and "cloud_provider" in browser_cfg:
-            provider_key = normalize_browser_cloud_provider(browser_cfg.get("cloud_provider"))
-            if provider_key in ("local", "camofox"):
-                # Camofox runs through the built-in browser tools, not a cloud provider.
-                _cached_cloud_provider = None
-                _cloud_provider_resolved = True
-                return None
-            if provider_key == "nous":
-                # Managed "Nous Subscription" is serviced by the Browser Use provider.
-                provider_key = "browser-use"
-        if provider_key:
-            resolved = _instantiate_explicit_cloud_provider(provider_key)
-            if resolved is None:
-                return None
-    except ValueError:
-        raise
-    except Exception as e:
-        # Config may be temporarily unreadable; still try auto-detect so
-        # env-based / managed-gateway credentials can resolve. Don't pin cache.
-        logger.debug("Could not read cloud_provider from config: %s", e)
-
-    if resolved is None and provider_key is None:
-        resolved = _autodetect_cloud_provider()
-    if resolved is None:
-        return None
-
-    _cached_cloud_provider = resolved
-    _cloud_provider_resolved = True
-    return _cached_cloud_provider
-
-
-from hermes_constants import is_termux as _is_termux_environment
-
-
-def _browser_install_hint() -> str:
-    if _is_termux_environment():
-        return "npm install -g agent-browser && agent-browser install"
-    return "npm install -g agent-browser && agent-browser install --with-deps"
+from hermes_constants import is_termux as _is_termux_environment  # noqa: F401  (read via origin)
 
 
 # Sentinel _find_agent_browser returns/caches to mean "resolve via npx" rather
@@ -860,133 +432,14 @@ NPX_AGENT_BROWSER_SENTINEL = "npx agent-browser"
 AGENT_BROWSER_NPX_SPEC = "agent-browser@^0.26.0"
 
 
-def _is_npx_agent_browser_sentinel(browser_cmd: str) -> bool:
-    return browser_cmd.strip() == NPX_AGENT_BROWSER_SENTINEL
-
-
-def _requires_real_termux_browser_install(browser_cmd: str) -> bool:
-    return _is_termux_environment() and _is_local_mode() and _is_npx_agent_browser_sentinel(browser_cmd)
-
-
-def _termux_browser_install_error() -> str:
-    return (
-        "Local browser automation on Termux cannot rely on the bare npx fallback. "
-        f"Install agent-browser explicitly first: {_browser_install_hint()}"
-    )
-
-
-def _is_local_mode() -> bool:
-    """Return True when the browser tool will use a local browser backend."""
-    if _get_cdp_override_raw():
-        return False
-    return _get_cloud_provider() is None
-
-
-def _is_local_backend() -> bool:
-    """Return True when the browser runs locally AND the terminal is also local.
-
-    SSRF protection only matters when the browser can reach networks the user's
-    terminal cannot: cloud backends, and a local browser paired with a
-    containerized terminal (docker/modal/daytona/ssh/singularity). A CDP
-    override is never trusted as local (that Chrome may live off-host) and MUST
-    be checked before the Camofox short-circuit so Camofox + override still
-    fails the local check; ``_is_local_mode`` treats overrides the same way —
-    keep the two in agreement.
-    """
-    if _get_cdp_override_raw():
-        return False
-    if _is_camofox_mode():
-        return True
-    if _get_cloud_provider() is not None:
-        return False
-    # Scope-aware: under gateway multiplexing the routed profile's terminal
-    # backend lives in the per-turn terminal scope, not the process env.
-    from tools.terminal_scope import terminal_env
-
-    terminal_backend = terminal_env("TERMINAL_ENV", "local").strip().lower()
-    return terminal_backend in ("local", "")
-
-
 _auto_local_for_private_urls_resolved = False
 _cached_auto_local_for_private_urls: bool = True
 
 
-def _get_browser_engine() -> str:
-    """Return the browser engine: ``auto`` (no ``--engine`` flag), ``lightpanda`` or ``chrome``.
-
-    ``browser.engine`` first, then ``AGENT_BROWSER_ENGINE``, then ``auto``;
-    cached. Lightpanda is much faster on navigation but has no graphical
-    renderer (no screenshots).
-    """
-    global _cached_browser_engine, _browser_engine_resolved
-    if _browser_engine_resolved:
-        return _cached_browser_engine
-
-    _browser_engine_resolved = True
-    # Config file takes priority; env var only if config didn't set a value.
-    _cached_browser_engine = _browser_cfg(
-        "engine", "auto",
-        lambda v: str(v).strip().lower() if v and str(v).strip() else "auto",
-        "browser.engine from config",
-    )
-    if _cached_browser_engine == "auto":
-        env_val = os.environ.get("AGENT_BROWSER_ENGINE", "").strip().lower()
-        if env_val:
-            _cached_browser_engine = env_val
-
-    # Validate: agent-browser only accepts "chrome" and "lightpanda".
-    _VALID_ENGINES = {"auto", "lightpanda", "chrome"}
-    if _cached_browser_engine not in _VALID_ENGINES:
-        logger.warning(
-            "Unknown browser engine %r (valid: %s), falling back to 'auto'",
-            _cached_browser_engine, ", ".join(sorted(_VALID_ENGINES)),
-        )
-        _cached_browser_engine = "auto"
-
-    return _cached_browser_engine
-
-
 _cached_headed_mode: Optional[bool] = None
 _headed_mode_resolved = False
 
 
-def _is_headed_mode() -> bool:
-    """Return True when the browser should launch in headed (visible) mode.
-
-    Reads ``config["browser"]["headed"]`` with ``AGENT_BROWSER_HEADED`` env
-    var as fallback.  Result is cached after the first call.
-    """
-    global _cached_headed_mode, _headed_mode_resolved
-    if _headed_mode_resolved:
-        return _cached_headed_mode  # type: ignore[return-value]
-
-    _headed_mode_resolved = True
-    _cached_headed_mode = _browser_cfg(
-        "headed", False,
-        lambda v: False if v is None else str(v).strip().lower() in ("true", "1", "yes"),
-        "browser.headed from config",
-    )
-    if not _cached_headed_mode:
-        env_val = os.environ.get("AGENT_BROWSER_HEADED", "").strip()
-        if env_val and env_val.lower() in ("true", "1", "yes"):
-            _cached_headed_mode = True
-
-    return _cached_headed_mode
-
-
-def _should_inject_engine(engine: str) -> bool:
-    """Return True when the engine flag should be added to agent-browser commands.
-
-    Only inject ``--engine`` for non-cloud, non-camofox local sessions where
-    the engine is explicitly set (not ``auto``).
-    """
-    if engine == "auto":
-        return False
-    if _is_camofox_mode():
-        return False
-    return _is_local_mode()
-
-
 from tools.browser_tool_lightpanda_fallback import (  # noqa: F401
     _using_lightpanda_engine,
     lightpanda_engine_status,
@@ -999,37 +452,6 @@ from tools.browser_tool_lightpanda_fallback import (  # noqa: F401
 )
 
 
-def _auto_local_for_private_urls() -> bool:
-    """``browser.auto_local_for_private_urls`` (default True), cached for the process.
-
-    When on, ``browser_navigate`` routes private/loopback/LAN URLs to a local
-    Chromium sidecar even with a cloud provider configured; public URLs keep
-    using the cloud provider in the same conversation.
-    """
-    global _auto_local_for_private_urls_resolved, _cached_auto_local_for_private_urls
-    if _auto_local_for_private_urls_resolved:
-        return _cached_auto_local_for_private_urls
-
-    _auto_local_for_private_urls_resolved = True
-    _cached_auto_local_for_private_urls = _browser_cfg(
-        "auto_local_for_private_urls", _cached_auto_local_for_private_urls, bool,
-        "auto_local_for_private_urls from config",
-    )
-    return _cached_auto_local_for_private_urls
-
-
-def _use_real_profile() -> bool:
-    """Return whether the user consented to real-profile local browsing.
-
-    Reads ``browser.use_real_profile`` (default False) on EVERY call — it is a
-    consent switch, so flipping it off must take effect without a restart, and
-    in a multiplexed gateway each profile's config must decide for itself.
-    The read is one YAML load per local session creation (not per command),
-    so there is no hot-path cost to keeping it uncached.
-    """
-    return _browser_cfg("use_real_profile", False, bool, "use_real_profile from config")
-
-
 # Session name for the single shared real-profile copy-browser. All consented
 # local browsing attaches to this one agent-browser session so concurrent
 # tasks reuse the same copy-browser instead of each launching a rival Chromium
@@ -1055,88 +477,6 @@ from tools.browser_tool_real_profile import (  # noqa: F401
 )
 
 
-def _agent_browser_argv(browser_cmd: str) -> list:
-    """Command prefix to invoke agent-browser (concrete binary or npx sentinel).
-
-    Concrete executable paths stay a single argv item (spaces intact); only the
-    synthetic npx sentinel expands. npx is resolved through the same
-    PATH + extended-PATH cascade ``_find_agent_browser`` uses — a bare
-    ``shutil.which("npx")`` would let a broken system npx shadow a healthy
-    Hermes-managed one. If npx isn't found at all (Termux, bare container) the
-    bare name is used so Popen raises a readable ``FileNotFoundError: 'npx'``.
-    ``--ignore-scripts``: AGENT_BROWSER_NPX_SPEC is a floating range, not an
-    exact pin — a compromised future patch must not run install-time scripts.
-    """
-    if _is_npx_agent_browser_sentinel(browser_cmd):
-        _npx_bin = _resolve_npx_bin() or "npx"
-        return [_npx_bin, "--ignore-scripts", "--prefer-offline", "-y", AGENT_BROWSER_NPX_SPEC]
-    return [browser_cmd]
-
-
-def _prepare_session_socket_dir(session_name: str) -> str:
-    """Create the per-session agent-browser socket dir and claim it with our PID.
-
-    Each session gets its own dir so parallel workers don't fight over the
-    default socket path ("Failed to create socket directory: Permission
-    denied"). The owner_pid file is written BEFORE first use: another hermes
-    process's orphan reaper rmtree's any agent-browser-* dir in the shared
-    tmpdir that carries no live owner, which would delete this one mid-command.
-    """
-    socket_dir = os.path.join(_socket_safe_tmpdir(), f"agent-browser-{session_name}")
-    os.makedirs(socket_dir, mode=0o700, exist_ok=True)
-    _write_owner_pid(socket_dir, session_name)
-    return socket_dir
-
-
-def _agent_browser_command_env(socket_dir: str) -> Dict[str, str]:
-    """Credential-scrubbed env for one agent-browser command.
-
-    Adds the discovery-time PATH fallbacks, the session socket dir, and the
-    daemon-side idle self-termination (``AGENT_BROWSER_IDLE_TIMEOUT_MS``,
-    agent-browser 0.24+) mirroring the Python-side inactivity janitor —
-    unless the user set the idle timeout explicitly.
-    """
-    env = _build_browser_env()
-    env["PATH"] = _merge_browser_path(env.get("PATH", ""))
-    env["AGENT_BROWSER_SOCKET_DIR"] = socket_dir
-    if "AGENT_BROWSER_IDLE_TIMEOUT_MS" not in env:
-        env["AGENT_BROWSER_IDLE_TIMEOUT_MS"] = str(BROWSER_SESSION_INACTIVITY_TIMEOUT * 1000)
-    return env
-
-
-def _popen_agent_browser(argv: List[str], env: Dict[str, str], socket_dir: str, tag: str) -> "subprocess.Popen":
-    """Spawn agent-browser with stdout/stderr redirected to ``socket_dir/_stdout_<tag>``.
-
-    Temp files instead of pipes: the CLI forks a background daemon that inherits
-    its fds, so with pipes ``communicate()`` never sees EOF until the timeout.
-    Windows: CREATE_NO_WINDOW only (NOT CREATE_NEW_PROCESS_GROUP, which on
-    Python 3.11 cancels asyncio's running loop task and surfaces as
-    KeyboardInterrupt in the CLI), STARTF_USESTDHANDLES so CreateProcess hands
-    the child ONLY our three handles (leaked parent console handles make the
-    Rust binary's daemon grandchild die silently), close_fds=True for the rest.
-    Returns the Popen; the caller reads/unlinks the two files.
-    """
-    stdout_path = os.path.join(socket_dir, f"_stdout_{tag}")
-    stderr_path = os.path.join(socket_dir, f"_stderr_{tag}")
-    stdout_fd = os.open(stdout_path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
-    stderr_fd = os.open(stderr_path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
-    try:
-        _popen_extra: dict = {}
-        if os.name == "nt":
-            _popen_extra["creationflags"] = windows_hide_flags()
-            _popen_extra["close_fds"] = True
-            _si = subprocess.STARTUPINFO()
-            _si.dwFlags |= subprocess.STARTF_USESTDHANDLES
-            _popen_extra["startupinfo"] = _si
-        return subprocess.Popen(
-            argv, stdout=stdout_fd, stderr=stderr_fd,
-            stdin=subprocess.DEVNULL, env=env, **_popen_extra,
-        )
-    finally:
-        os.close(stdout_fd)
-        os.close(stderr_fd)
-
-
 def _url_is_private(url: str) -> bool:
     """Return True when the URL's host resolves to a private/LAN/loopback address.
 
@@ -1275,38 +615,6 @@ def _last_session_key(task_id: str) -> str:
     return task_id
 
 
-def _allow_private_urls() -> bool:
-    """Return whether the browser is allowed to navigate to private/internal addresses.
-
-    Reads ``config["browser"]["allow_private_urls"]``. Single-profile calls
-    cache the result for the process lifetime; multiplexed profile turns resolve
-    their context-local config on each call. Defaults to ``False`` (SSRF
-    protection active).
-    """
-    global _cached_allow_private_urls, _allow_private_urls_resolved
-
-    # The profile multiplexer scopes config with a ContextVar while sharing
-    # this module. Never reuse another profile's private-network opt-out.
-    if get_hermes_home_override() is not None:
-        return _resolve_allow_private_urls()
-
-    if _allow_private_urls_resolved:
-        return _cached_allow_private_urls
-
-    _allow_private_urls_resolved = True
-    _cached_allow_private_urls = _resolve_allow_private_urls()
-    return _cached_allow_private_urls
-
-
-def _resolve_allow_private_urls() -> bool:
-    """Read the browser private-URL toggle from the active config scope."""
-    return _browser_cfg(
-        "allow_private_urls", False,
-        lambda v: is_truthy_value(v, default=False),
-        "allow_private_urls from config",
-    )
-
-
 def _socket_safe_tmpdir() -> str:
     """Short temp dir for Unix domain sockets.
 
@@ -1417,8 +725,7 @@ class _BrowserSessionBackend:
         if reason is None:
             return True
         logger.info(
-            "Recycling suspect browser session %s before reuse (%s)",
-            self._session_key, reason,
+            "Recycling suspect browser session %s before reuse (%s)", self._session_key, reason
         )
         try:
             _cleanup_single_browser_session(self._session_key)
@@ -1435,6 +742,7 @@ def _browser_session_backend(session_key: str) -> _BrowserSessionBackend:
     """Return the SuspectableBackend adapter for ``session_key``."""
     return _BrowserSessionBackend(session_key)
 
+
 # Background cleanup thread state
 _cleanup_thread = None
 _cleanup_running = False
@@ -1443,97 +751,35 @@ _cleanup_running = False
 _cleanup_lock = threading.Lock()
 
 
-def _session_expiry_timestamp(session_info: Dict[str, Any]) -> Optional[float]:
-    """Return a provider-authoritative session expiry as epoch seconds.
-
-    Cloud providers may omit ``expires_at``. Unknown or malformed values are
-    therefore treated as having no known expiry, preserving the existing
-    lifecycle for local browsers and providers without an expiry contract.
-    """
-    value = session_info.get("expires_at")
-    if isinstance(value, (int, float)) and not isinstance(value, bool):
-        return float(value)
-    if not isinstance(value, str) or not value.strip():
-        return None
-
-    normalized = value.strip()
-    if normalized.endswith(("Z", "z")):
-        normalized = f"{normalized[:-1]}+00:00"
-    try:
-        parsed = datetime.fromisoformat(normalized)
-    except ValueError:
-        logger.warning("Ignoring invalid cloud browser session expiry timestamp")
-        return None
-    if parsed.tzinfo is None:
-        parsed = parsed.replace(tzinfo=timezone.utc)
-    return parsed.timestamp()
-
-
-def _session_has_expired(
-    session_info: Dict[str, Any], *, now: Optional[float] = None
-) -> bool:
-    """Return whether a cached browser session crossed its provider deadline."""
-    expires_at = _session_expiry_timestamp(session_info)
-    if expires_at is None:
-        return False
-    return (time.time() if now is None else now) >= expires_at
-
-
-def _emergency_cleanup_all_sessions():
-    """
-    Emergency cleanup of all active browser sessions.
-    Called on process exit or interrupt to prevent orphaned sessions.
-
-    Also runs the orphan reaper to clean up daemons left behind by previously
-    crashed hermes processes — this way every clean hermes exit sweeps
-    accumulated orphans, not just ones that actively used the browser tool.
-    """
-    global _cleanup_done
-    if _cleanup_done:
-        return
-    _cleanup_done = True
-
-    # Clean up this process's own sessions first, so their owner_pid files
-    # are removed before the reaper scans.
-    # Real-profile Chrome processes are launched directly (not by
-    # agent-browser), so the session cleanup below never reaps them.
-    try:
-        _terminate_real_profile_chrome()
-    except Exception as e:
-        logger.debug("Real-profile chrome cleanup on exit failed: %s", e)
-    if _active_sessions:
-        logger.info("Emergency cleanup: closing %s active session(s)...",
-                    len(_active_sessions))
-        try:
-            cleanup_all_browsers()
-        except Exception as e:
-            logger.error("Emergency cleanup error: %s", e)
-        finally:
-            with _cleanup_lock:
-                _active_sessions.clear()
-                _session_last_activity.clear()
-                _session_owner_homes.clear()
-                _cleanup_failures.clear()
-                _recording_sessions.clear()
-
-    # Lightpanda servers (Browser Use mode) are processes we spawned; the
-    # session cleanup above stops the tracked ones, this catches any that
-    # fell out of ``_active_sessions``.
-    try:
-        from tools.browser_lightpanda import stop_all_lightpanda
-
-        stop_all_lightpanda()
-    except Exception as e:
-        logger.debug("Lightpanda cleanup on exit failed: %s", e)
-
-    # Sweep orphans from other crashed hermes processes.  Safe even if we
-    # never used the browser — uses owner_pid liveness to avoid reaping
-    # daemons owned by other live hermes processes.
-    try:
-        _reap_orphaned_browser_sessions()
-    except Exception as e:
-        logger.debug("Orphan reap on exit failed: %s", e)
-
+from tools.browser_tool_lifecycle import (  # noqa: F401  (re-exported; tests patch tools.browser_tool.<name>)
+    _session_expiry_timestamp,
+    _session_has_expired,
+    _emergency_cleanup_all_sessions,
+    _session_owner_scope,
+    _cleanup_inactive_browser_sessions,
+    _write_owner_pid,
+    _verify_reapable_browser_daemon,
+    _socket_dir_idle_seconds,
+    _owner_pid_alive,
+    _reap_socket_dir,
+    _reap_orphaned_browser_sessions,
+    _browser_cleanup_thread_worker,
+    _start_browser_cleanup_thread,
+    _stop_browser_cleanup_thread,
+    _update_session_activity,
+    _kill_process_tree,
+    _legacy_kill_process_tree,
+    _pid_exists,
+    _cleanup_old_screenshots,
+    _cleanup_old_recordings,
+    _drop_last_active_binding,
+    cleanup_browser,
+    _kill_verified_daemon,
+    _release_session_resources,
+    _force_reap_browser_session,
+    _cleanup_single_browser_session,
+    cleanup_all_browsers,
+)
 
 # atexit only — NO SIGINT/SIGTERM handlers calling sys.exit(): a SystemExit
 # raised inside a prompt_toolkit key-binding callback corrupts the coroutine
@@ -1545,398 +791,6 @@ atexit.register(_emergency_cleanup_all_sessions)
 # Inactivity Cleanup Functions
 # =============================================================================
 
-@contextlib.contextmanager
-def _session_owner_scope(task_id: str):
-    """Run under the Hermes home + secret scope owning ``task_id``'s session (no-op if unrecorded).
-
-    The janitor thread is process-global, so each teardown must re-enter its
-    OWN profile's scope rather than inherit the spawning profile's; never falls
-    through to ``os.environ``.
-    """
-    owner_home = _session_owner_homes.get(task_id)
-    if owner_home is None:
-        yield
-        return
-
-    from agent.secret_scope import (
-        build_profile_secret_scope,
-        reset_secret_scope,
-        set_secret_scope,
-    )
-    from hermes_cli.env_loader import hydrate_profile_secret_sources
-
-    home_token = set_hermes_home_override(owner_home)
-    try:
-        hydrate_profile_secret_sources(Path(owner_home))
-        secret_token = set_secret_scope(build_profile_secret_scope(Path(owner_home)))
-        try:
-            yield
-        finally:
-            reset_secret_scope(secret_token)
-    finally:
-        reset_hermes_home_override(home_token)
-
-
-def _cleanup_inactive_browser_sessions():
-    """Close sessions inactive longer than the timeout (called by the cleanup thread).
-
-    Each session is torn down under its owner profile's scope. A session whose
-    cleanup keeps failing is force-reaped after MAX_INACTIVITY_CLEANUP_FAILURES
-    attempts instead of retrying forever; only a successful cleanup clears its
-    failure count.
-    """
-    current_time = time.time()
-    sessions_to_cleanup = []
-
-    with _cleanup_lock:
-        for task_id, last_time in list(_session_last_activity.items()):
-            if current_time - last_time > BROWSER_SESSION_INACTIVITY_TIMEOUT:
-                sessions_to_cleanup.append(task_id)
-
-    for task_id in sessions_to_cleanup:
-        elapsed = int(current_time - _session_last_activity.get(task_id, current_time))
-        logger.info("Cleaning up inactive session for task: %s (inactive for %ss)", task_id, elapsed)
-        try:
-            with _session_owner_scope(task_id):
-                cleanup_browser(task_id)
-            with _cleanup_lock:
-                _session_last_activity.pop(task_id, None)
-                _session_owner_homes.pop(task_id, None)
-                _cleanup_failures.pop(task_id, None)
-        except Exception as e:
-            with _cleanup_lock:
-                failures = _cleanup_failures[task_id] = _cleanup_failures.get(task_id, 0) + 1
-            if failures < MAX_INACTIVITY_CLEANUP_FAILURES:
-                logger.warning("Error cleaning up inactive session %s (attempt %d/%d): %s",
-                               task_id, failures, MAX_INACTIVITY_CLEANUP_FAILURES, e)
-                continue
-            logger.error("Browser cleanup failed %d times for inactive session %s; "
-                         "force-reaping: %s", failures, task_id, e)
-            try:
-                with _session_owner_scope(task_id):
-                    _force_reap_browser_session(task_id)
-            except Exception as reap_exc:
-                logger.error("Force-reap of browser session %s failed: %s", task_id, reap_exc)
-            finally:
-                with _cleanup_lock:
-                    _session_owner_homes.pop(task_id, None)
-                    _cleanup_failures.pop(task_id, None)
-
-
-def _write_owner_pid(socket_dir: str, session_name: str) -> None:
-    """Record the current hermes PID as the owner of a browser socket dir.
-
-    Written atomically to ``<socket_dir>/<session_name>.owner_pid`` so the
-    orphan reaper can distinguish daemons owned by a live hermes process
-    (don't reap) from daemons whose owner crashed (reap).  Best-effort —
-    an OSError here just falls back to the legacy ``tracked_names``
-    heuristic in the reaper.
-    """
-    try:
-        path = os.path.join(socket_dir, f"{session_name}.owner_pid")
-        with open(path, "w", encoding="utf-8") as f:
-            f.write(str(os.getpid()))
-    except OSError as exc:
-        logger.debug("Could not write owner_pid file for %s: %s",
-                     session_name, exc)
-
-
-def _verify_reapable_browser_daemon(daemon_pid: int, socket_dir: str,
-                                    session_name: str) -> bool:
-    """Confirm a live PID is genuinely *this* session's agent-browser daemon.
-
-    The ``.pid`` file lives in a world-writable, predictably-named temp dir and
-    is written by the daemon, not us: a same-user actor can plant one pointing
-    at a victim PID, or a recycled PID can land on an unrelated process — and
-    reaping is a *tree* kill, i.e. an arbitrary-process DoS. Two psutil checks
-    must both pass: (1) identity — ``agent-browser`` in the name or cmdline;
-    (2) binding — the socket dir path/basename in the cmdline, or
-    ``AGENT_BROWSER_SOCKET_DIR`` in its environ. (2) is the real spoof defense:
-    an attacker would need a real daemon embedding this exact path, which they
-    could already signal. Fail-closed on any ambiguity (unreadable cmdline, no
-    match): refuse to reap and leave process and socket dir alone.
-    """
-    try:
-        import psutil
-    except ImportError:  # psutil is a hard dep; defensive only
-        logger.warning(
-            "Refusing to reap browser daemon PID %d (session %s): "
-            "psutil unavailable for identity verification",
-            daemon_pid, session_name)
-        return False
-
-    try:
-        proc = psutil.Process(daemon_pid)
-        name = (proc.name() or "").lower()
-        cmdline = " ".join(proc.cmdline() or []).lower()
-    except psutil.NoSuchProcess:
-        # Vanished between the liveness check and now — nothing to reap.
-        return False
-    except (psutil.AccessDenied, OSError) as exc:
-        logger.warning(
-            "Refusing to reap browser daemon PID %d (session %s): "
-            "could not read process identity (%s)",
-            daemon_pid, session_name, exc)
-        return False
-
-    looks_like_browser = "agent-browser" in name or "agent-browser" in cmdline
-    if not looks_like_browser:
-        logger.warning(
-            "Refusing to reap PID %d (session %s): not an agent-browser "
-            "process (name=%r)", daemon_pid, session_name, name)
-        return False
-
-    # Binding check: the live process must reference *this* socket dir.
-    socket_dir_l = socket_dir.lower()
-    socket_base_l = os.path.basename(socket_dir).lower()
-    bound = socket_dir_l in cmdline or (
-        socket_base_l and socket_base_l in cmdline)
-    if not bound:
-        try:
-            env_dir = (proc.environ() or {}).get(
-                "AGENT_BROWSER_SOCKET_DIR", "")
-            bound = bool(env_dir) and os.path.normpath(env_dir) == \
-                os.path.normpath(socket_dir)
-        except (psutil.AccessDenied, psutil.NoSuchProcess, OSError):
-            # environ() can be denied even same-user on some platforms.
-            # cmdline already failed to bind — fail closed.
-            bound = False
-
-    if not bound:
-        logger.warning(
-            "Refusing to reap agent-browser PID %d: not bound to session "
-            "socket dir %s (possible recycled PID or planted pid file)",
-            daemon_pid, socket_dir)
-        return False
-
-    return True
-
-
-def _socket_dir_idle_seconds(socket_dir: str) -> Optional[float]:
-    """Seconds since anything in ``socket_dir`` was last written; None if unknown (fail safe).
-
-    Every command writes ``_stdout_<cmd>`` / ``_stderr_<cmd>`` there, so the
-    newest mtime is a last-activity marker that survives hermes restarts and
-    lost in-memory bookkeeping. The dir's own mtime is not enough — rewriting
-    an existing ``_stdout_click`` doesn't touch it — so entries are scanned too.
-    """
-    try:
-        latest = os.path.getmtime(socket_dir)
-    except OSError:
-        return None
-
-    try:
-        with os.scandir(socket_dir) as entries:
-            for entry in entries:
-                try:
-                    latest = max(latest, entry.stat().st_mtime)
-                except OSError:
-                    continue
-    except OSError:
-        pass  # dir mtime alone is still a usable lower bound
-
-    return max(0.0, time.time() - latest)
-
-
-def _owner_pid_alive(socket_dir: str, session_name: str) -> Tuple[Optional[int], Optional[bool]]:
-    """Read ``<session>.owner_pid`` and report ``(pid, alive)``; ``(None, None)`` when missing/corrupt."""
-    owner_pid_file = os.path.join(socket_dir, f"{session_name}.owner_pid")
-    if not os.path.isfile(owner_pid_file):
-        return None, None
-    try:
-        owner_pid = int(Path(owner_pid_file).read_text(encoding="utf-8").strip())
-        # ``os.kill(pid, 0)`` is NOT a no-op on Windows; use the cross-platform check.
-        from gateway.status import _pid_exists
-        return owner_pid, _pid_exists(owner_pid)
-    except (ValueError, OSError):
-        return None, None  # corrupt file — fall through to legacy handling
-
-
-def _reap_socket_dir(socket_dir: str, session_name: str, tracked_names: set) -> bool:
-    """Reap one ``agent-browser-<session>`` dir if orphaned; return True when a daemon was killed.
-
-    Ownership priority: (1) a live ``owner_pid`` means another hermes process
-    owns it — leave it alone UNLESS it is untracked here and idle past
-    ``BROWSER_ORPHAN_GRACE_SECONDS`` (owner-alive alone made leaked daemons
-    immortal: in-memory tracking is lost on any exception path and the daemon's
-    own idle timeout doesn't fire when it is wedged); (2) no owner_pid (legacy)
-    falls back to this process's tracking. A pidless dir is only stale after the
-    grace period — deleting it immediately races the creator's first stdout open.
-    The daemon PID is verified as ours before a tree-kill (world-writable dir,
-    recycled PIDs), and refused without a start-time fingerprint.
-    """
-    owner_pid, owner_alive = _owner_pid_alive(socket_dir, session_name)
-    if owner_alive is True:
-        if session_name in tracked_names:
-            return False
-        idle_s = _socket_dir_idle_seconds(socket_dir)
-        if idle_s is None or idle_s < BROWSER_ORPHAN_GRACE_SECONDS:
-            return False  # unknown age or within grace — fail safe
-        logger.warning(
-            "Browser session %s has a live owner (PID %s) but is untracked "
-            "and idle for %ds (grace %ds) — treating as leaked and reaping",
-            session_name, owner_pid, int(idle_s),
-            BROWSER_ORPHAN_GRACE_SECONDS)
-    elif owner_alive is None and session_name in tracked_names:
-        return False
-
-    pid_file = os.path.join(socket_dir, f"{session_name}.pid")
-    if not os.path.isfile(pid_file):
-        idle_s = _socket_dir_idle_seconds(socket_dir)
-        if idle_s is None or idle_s < BROWSER_ORPHAN_GRACE_SECONDS:
-            return False
-        shutil.rmtree(socket_dir, ignore_errors=True)
-        return False
-
-    try:
-        daemon_pid = int(Path(pid_file).read_text(encoding="utf-8").strip())
-    except (ValueError, OSError):
-        shutil.rmtree(socket_dir, ignore_errors=True)
-        return False
-
-    from gateway.status import _pid_exists
-    if not _pid_exists(daemon_pid):
-        shutil.rmtree(socket_dir, ignore_errors=True)
-        return False
-
-    if not _verify_reapable_browser_daemon(daemon_pid, socket_dir, session_name):
-        return False  # leave process and dir for a later sweep once the imposter PID is gone
-
-    # Tree-kill so Chromium children (renderer, GPU, ...) go too, not just the daemon.
-    reaped = False
-    try:
-        from gateway.status import get_process_start_time
-        from tools.process_registry import ProcessRegistry
-        daemon_start = get_process_start_time(daemon_pid)
-        if daemon_start is None:
-            logger.warning(
-                "Refusing to reap browser daemon PID %d (session %s): "
-                "no start-time fingerprint available", daemon_pid, session_name)
-            return False
-        ProcessRegistry._terminate_host_pid(daemon_pid, daemon_start)
-        logger.info("Reaped orphaned browser daemon PID %d (session %s)",
-                    daemon_pid, session_name)
-        reaped = True
-    except (ProcessLookupError, PermissionError, OSError):
-        pass
-    shutil.rmtree(socket_dir, ignore_errors=True)
-    return reaped
-
-
-def _reap_orphaned_browser_sessions():
-    """Kill agent-browser daemons whose owning hermes process is gone.
-
-    When the process that created a session exits uncleanly (SIGKILL, crash,
-    gateway restart) the in-memory ``_active_sessions`` tracking is lost but the
-    node + Chromium processes keep running. Scans the tmp dir for
-    ``agent-browser-*`` socket dirs and applies ``_reap_socket_dir``'s ownership
-    rules (owner_pid file first — cross-process safe, two hermes instances never
-    reap each other — then in-process tracking for legacy daemons).
-    Safe to call from any context — atexit, cleanup thread, or on demand.
-    """
-    import glob
-
-    # Lightpanda servers (Browser Use mode) keep their own records (no
-    # agent-browser socket dir); sweep them with the same owner-liveness rule
-    # BEFORE the daemon scan, which may return early.
-    try:
-        from tools.browser_lightpanda import reap_orphaned_lightpanda
-
-        reap_orphaned_lightpanda()
-    except Exception as e:
-        logger.debug("Lightpanda orphan reap failed: %s", e)
-
-    tmpdir = _socket_safe_tmpdir()
-    socket_dirs = []
-    for prefix in ("agent-browser-h_*", "agent-browser-cdp_*", "agent-browser-hermes_*"):
-        socket_dirs += glob.glob(os.path.join(tmpdir, prefix))
-    if not socket_dirs:
-        return
-
-    with _cleanup_lock:
-        tracked_names = {
-            info.get("session_name")
-            for info in _active_sessions.values()
-            if info.get("session_name")
-        }
-
-    reaped = 0
-    for socket_dir in socket_dirs:
-        session_name = os.path.basename(socket_dir).removeprefix("agent-browser-")
-        if session_name and _reap_socket_dir(socket_dir, session_name, tracked_names):
-            reaped += 1
-
-    if reaped:
-        logger.info("Reaped %d orphaned browser session(s) from previous run(s)", reaped)
-
-
-def _browser_cleanup_thread_worker():
-    """Every 30s: close sessions idle past BROWSER_SESSION_INACTIVITY_TIMEOUT.
-
-    Also reaps orphaned daemons on startup AND every BROWSER_ORPHAN_REAP_INTERVAL
-    seconds — a daemon can fall out of in-memory tracking at any point in a
-    long-lived process, and a startup-only reap could never recover from that.
-    """
-    reap_every_cycles = max(1, round(BROWSER_ORPHAN_REAP_INTERVAL / 30))
-    cycle = 0
-
-    while _cleanup_running:
-        # cycle 0 is the startup reap; then every reap_every_cycles.
-        if cycle % reap_every_cycles == 0:
-            try:
-                _reap_orphaned_browser_sessions()
-            except Exception as e:
-                logger.warning("Orphan reap error: %s", e)
-        cycle += 1
-
-        try:
-            _cleanup_inactive_browser_sessions()
-        except Exception as e:
-            logger.warning("Cleanup thread error: %s", e)
-
-        # Sleep in 1-second intervals so we can stop quickly if needed
-        for _ in range(30):
-            if not _cleanup_running:
-                break
-            time.sleep(1)
-
-
-def _start_browser_cleanup_thread():
-    """Start the background cleanup thread if not already running."""
-    global _cleanup_thread, _cleanup_running
-
-    with _cleanup_lock:
-        if _cleanup_thread is None or not _cleanup_thread.is_alive():
-            _cleanup_running = True
-            _cleanup_thread = threading.Thread(
-                target=_browser_cleanup_thread_worker,
-                daemon=True,
-                name="browser-cleanup"
-            )
-            _cleanup_thread.start()
-            logger.info("Started inactivity cleanup thread (timeout: %ss)", BROWSER_SESSION_INACTIVITY_TIMEOUT)
-
-
-def _stop_browser_cleanup_thread():
-    """Stop the background cleanup thread."""
-    global _cleanup_running
-    _cleanup_running = False
-    if _cleanup_thread is not None:
-        _cleanup_thread.join(timeout=5)
-
-
-def _update_session_activity(task_id: str):
-    """Update the last activity timestamp for a session.
-
-    Also records the owning Hermes home on first sight so the process-global
-    janitor can tear the session down under its owner's scope.  An
-    activity touch deliberately does NOT reset ``_cleanup_failures`` — only a
-    successful cleanup does.
-    """
-    with _cleanup_lock:
-        _session_last_activity[task_id] = time.time()
-        _session_owner_homes.setdefault(task_id, str(get_hermes_home()))
-
 
 # Register cleanup thread stop on exit
 atexit.register(_stop_browser_cleanup_thread)
@@ -2001,8 +855,7 @@ BROWSER_TOOL_SCHEMAS = [
                     "description": "The element reference from the snapshot (e.g., '@e3')"
                 },
                 "text": {
-                    "type": "string",
-                    "description": "The text to type into the field"
+                    "type": "string", "description": "The text to type into the field"
                 }
             },
             "required": ["ref", "text"]
@@ -2015,9 +868,7 @@ BROWSER_TOOL_SCHEMAS = [
             "type": "object",
             "properties": {
                 "direction": {
-                    "type": "string",
-                    "enum": ["up", "down"],
-                    "description": "Direction to scroll"
+                    "type": "string", "enum": ["up", "down"], "description": "Direction to scroll"
                 }
             },
             "required": ["direction"]
@@ -2027,9 +878,7 @@ BROWSER_TOOL_SCHEMAS = [
         "name": "browser_back",
         "description": "Navigate back to the previous page in browser history. Requires browser_navigate to be called first.",
         "parameters": {
-            "type": "object",
-            "properties": {},
-            "required": []
+            "type": "object", "properties": {}, "required": []
         }
     },
     {
@@ -2050,9 +899,7 @@ BROWSER_TOOL_SCHEMAS = [
         "name": "browser_get_images",
         "description": "Get a list of all images on the current page with their URLs and alt text. Useful for finding images to analyze with the vision tool. Requires browser_navigate to be called first.",
         "parameters": {
-            "type": "object",
-            "properties": {},
-            "required": []
+            "type": "object", "properties": {}, "required": []
         }
     },
     {
@@ -2100,492 +947,6 @@ BROWSER_TOOL_SCHEMAS = [
 # Utility Functions
 # ============================================================================
 
-def _create_local_session(task_id: str, allow_real_profile: bool = True) -> Dict[str, str]:
-    import uuid
-
-    # Real-profile consent: attach this local session (via CDP) to the user's
-    # browser running on a hermes-owned SNAPSHOT of their real profile, logins
-    # included. Fail closed on resolver/launch errors — a consented user must
-    # never be silently downgraded to a throwaway. The hybrid private-URL
-    # sidecar passes allow_real_profile=False: handing the user's cookie jar to
-    # an arbitrary internal host the model chose is a larger, unconsented
-    # exposure than the routing rule protects against (and a real-profile
-    # failure must not break private-URL routing).
-    if allow_real_profile:
-        cdp_url, err = _real_profile_cdp()
-        if err:
-            raise RuntimeError(err)
-        if cdp_url:
-            session_name = f"rp_{uuid.uuid4().hex[:10]}"
-            logger.info(
-                "Created real-profile local session %s for task %s", session_name, task_id
-            )
-            return {
-                "session_name": session_name,
-                "bb_session_id": None,
-                "cdp_url": _resolve_cdp_override(cdp_url),
-                "features": {"local": True, "real_profile": True},
-            }
-
-    # Browser Use mode drives whatever CDP endpoint it is handed; with
-    # ``browser.engine: lightpanda`` that endpoint is a Hermes-spawned
-    # ``lightpanda serve``. The built-in tools never reach this branch —
-    # they are hidden in Browser Use mode — and keep driving Lightpanda via
-    # ``agent-browser --engine lightpanda`` on the plain local session below.
-    if _is_browser_use_cli_mode() and _using_lightpanda_engine():
-        return _create_lightpanda_session(task_id)
-
-    session_name = f"h_{uuid.uuid4().hex[:10]}"
-    logger.info("Created local browser session %s for task %s",
-                session_name, task_id)
-    return {
-        "session_name": session_name,
-        "bb_session_id": None,
-        "cdp_url": None,
-        "features": {"local": True},
-    }
-
-
-def _create_lightpanda_session(task_id: str) -> Dict[str, Any]:
-    """Spawn ``lightpanda serve`` for this session key (Browser Use mode)."""
-    import uuid
-    from tools.browser_lightpanda import launch_lightpanda
-
-    session_name = f"lp_{uuid.uuid4().hex[:10]}"
-    server, err = launch_lightpanda(
-        session_name, block_private_networks=not _is_local_backend()
-    )
-    if err:
-        raise RuntimeError(err)
-    logger.info(
-        "Created Lightpanda session %s (port %s) for task %s",
-        session_name, server.port, task_id,
-    )
-    return {
-        "session_name": session_name,
-        "bb_session_id": None,
-        "cdp_url": server.cdp_url,
-        "features": {"local": True, "lightpanda": True},
-    }
-
-
-def _local_backend_process_dead(session_info: Dict[str, Any]) -> bool:
-    """True for a Lightpanda session whose ``lightpanda serve`` is gone."""
-    if not (session_info.get("features") or {}).get("lightpanda"):
-        return False
-    from tools.browser_lightpanda import get_server
-
-    server = get_server(session_info.get("session_name", ""))
-    return server is None or not server.is_alive()
-
-
-def _create_cdp_session(task_id: str, cdp_url: str) -> Dict[str, str]:
-    """Create a session that connects to a user-supplied CDP endpoint."""
-    import uuid
-    session_name = f"cdp_{uuid.uuid4().hex[:10]}"
-    logger.info("Created CDP browser session %s → %s for task %s",
-                session_name, _sanitize_url_for_logs(cdp_url), task_id)
-    return {
-        "session_name": session_name,
-        "bb_session_id": None,
-        "cdp_url": cdp_url,
-        "features": {"cdp_override": True},
-    }
-
-
-def _create_cloud_session_or_fallback(task_id: str, provider) -> Dict[str, Any]:
-    """Create a cloud session; fall back to local Chromium (marked degraded) on failure.
-
-    Some cloud providers (Browser-Use v3) return an HTTP CDP discovery URL
-    instead of a raw websocket endpoint, so ``cdp_url`` is resolved here.
-    """
-    try:
-        session_info = provider.create_session(task_id)
-        if not session_info or not isinstance(session_info, dict):
-            raise ValueError(f"Cloud provider returned invalid session: {session_info!r}")
-        if session_info.get("cdp_url"):
-            session_info = dict(session_info)
-            session_info["cdp_url"] = _resolve_cdp_override(str(session_info["cdp_url"]))
-        return session_info
-    except Exception as e:
-        provider_name = type(provider).__name__
-        logger.warning(
-            "Cloud provider %s failed (%s); attempting fallback to local "
-            "Chromium for task %s",
-            provider_name, e, task_id,
-            exc_info=True,
-        )
-        try:
-            session_info = _create_local_session(task_id)
-        except Exception as local_error:
-            raise RuntimeError(
-                f"Cloud provider {provider_name} failed ({e}) and local "
-                f"fallback also failed ({local_error})"
-            ) from e
-        # Mark session as degraded for observability
-        if isinstance(session_info, dict):
-            session_info = dict(session_info)
-            session_info["fallback_from_cloud"] = True
-            session_info["fallback_reason"] = str(e)
-            session_info["fallback_provider"] = provider_name
-        return session_info
-
-
-def _create_session_for_key(task_id: str, force_local: bool) -> Dict[str, Any]:
-    """Create a fresh session for ``task_id`` (runs OUTSIDE the lock: cloud mode makes a network call).
-
-    Precedence: CDP override > hybrid local sidecar > cloud provider > local.
-    The hybrid private-URL sidecar NEVER gets the real profile — presenting real
-    cookies to an arbitrary LAN host the model routed there is unconsented
-    exposure (see ``_create_local_session``).
-    """
-    cdp_override = _get_cdp_override()
-    if cdp_override and not force_local:
-        return _create_cdp_session(task_id, cdp_override)
-    if force_local:
-        return _create_local_session(task_id, allow_real_profile=False)
-    provider = _get_cloud_provider()
-    if provider is None:
-        return _create_local_session(task_id)
-    return _create_cloud_session_or_fallback(task_id, provider)
-def _get_session_info(task_id: Optional[str] = None) -> Dict[str, Any]:
-    """Get or create session info for a session key (thread-safe).
-
-    ``task_id`` may carry the ``::local`` suffix (hybrid local sidecar), which
-    forces a local Chromium even when a cloud provider is configured. Also
-    starts the inactivity cleanup thread and touches activity tracking.
-    Returns a dict with ``session_name`` (always) plus ``bb_session_id`` /
-    ``cdp_url`` for cloud sessions.
-    """
-    if task_id is None:
-        task_id = "default"
-
-    # Start the cleanup thread if not running (handles inactivity timeouts)
-    _start_browser_cleanup_thread()
-
-    # Update activity timestamp for this session
-    _update_session_activity(task_id)
-
-    with _cleanup_lock:
-        # Check if we already have a session for this task
-        existing_session = _active_sessions.get(task_id)
-
-    # Suspect-session recycle: a previous command
-    # timeout marked this cached session suspect via the SuspectableBackend
-    # adapter.  ensure_healthy() tears it down here, at next use, and we fall
-    # through to create a fresh session — the expensive recycle lives on this
-    # path, not on the timeout path (mark must stay cheap).
-    if existing_session is not None and not _browser_session_backend(task_id).ensure_healthy():
-        # Teardown removes the activity entry; the replacement must be
-        # tracked by the inactivity reaper like an initial session.
-        _update_session_activity(task_id)
-        with _cleanup_lock:
-            replacement = _active_sessions.get(task_id)
-        if replacement is not None and replacement is not existing_session:
-            # Another thread already recycled and re-created it.
-            return replacement
-        existing_session = None
-
-    if existing_session is not None:
-        if (
-            not _session_has_expired(existing_session)
-            and not _local_backend_process_dead(existing_session)
-        ):
-            return existing_session
-
-        logger.info(
-            "Replacing expired or dead browser session for task %s",
-            task_id,
-        )
-        _cleanup_single_browser_session(task_id)
-        # Cleanup removes the activity entry. The replacement session must be
-        # tracked by the inactivity reaper just like an initial session.
-        _update_session_activity(task_id)
-
-        # Guard against a concurrent replacement: another thread may have
-        # already cleaned up the expired session and created a fresh one
-        # while we were waiting.  If so, return the live replacement instead
-        # of falling through to create yet another session.
-        with _cleanup_lock:
-            replacement = _active_sessions.get(task_id)
-        if replacement is not None and replacement is not existing_session:
-            return replacement
-
-    # Hybrid routing: session keys ending with ``::local`` force a local
-    # Chromium regardless of the globally-configured cloud provider.  Public
-    # URLs in the same conversation continue to use the cloud session under
-    # the bare task_id key.
-    force_local = _is_local_sidecar_key(task_id)
-    session_info = _create_session_for_key(task_id, force_local)
-
-    with _cleanup_lock:
-        # Double-check: another thread may have created a session while we
-        # were doing the network call. Use the existing one to avoid leaking
-        # orphan cloud sessions.
-        if task_id in _active_sessions:
-            return _active_sessions[task_id]
-        session_info = dict(session_info)
-        session_info.setdefault("session_key", task_id)
-        session_info.setdefault("owner_task_id", _bare_task_id_for_session_key(task_id))
-        _active_sessions[task_id] = session_info
-        # A brand-new session is healthy by definition — drop any stale
-        # suspect flag left by a wedged-path eviction of its predecessor.
-        _suspect_browser_sessions.pop(task_id, None)
-
-    # Lazy-start the CDP supervisor now that the session exists (if the
-    # backend surfaces a CDP URL via override or session_info["cdp_url"]).
-    # Idempotent; swallows errors. See _ensure_cdp_supervisor for details.
-    # Skip for local sidecars — they have no CDP URL — and for Lightpanda
-    # sessions: those only exist in Browser Use mode, where the browser_*
-    # tools that consume supervisor state are hidden, so the supervisor
-    # would just hold an idle second CDP connection to the process.
-    if not force_local and not (session_info.get("features") or {}).get("lightpanda"):
-        _ensure_cdp_supervisor(task_id)
-
-    return session_info
-
-
-def _agent_browser_candidate_present(path: str | None) -> bool:
-    if not path:
-        return False
-    if " " in path and path.split()[0].endswith("npx"):
-        return True
-    return os.path.exists(path) and (os.name == "nt" or os.access(path, os.X_OK))
-
-
-def _resolve_npx_bin() -> Optional[str]:
-    """Resolve a runnable npx, preferring the Hermes-managed/Homebrew extended PATH.
-
-    Bare PATH first would let a broken system npx shadow a healthy managed one
-    with no recovery, so every candidate is validated with ``node_tool_runnable``
-    before being trusted.
-    """
-    extended_path = _merge_browser_path("")
-    if extended_path:
-        extended_npx = shutil.which("npx", path=extended_path)
-        if extended_npx and node_tool_runnable(extended_npx):
-            return extended_npx
-    npx_path = shutil.which("npx")
-    if npx_path and node_tool_runnable(npx_path):
-        return npx_path
-    return None
-
-
-def _agent_browser_candidates(extended_path: str):
-    """Yield agent-browser lookup candidates in resolution order (lazily — each is a filesystem probe).
-
-    Order: ambient PATH (global install) → extended PATH (Hermes-managed Node,
-    macOS versioned Homebrew, Termux/system dirs) → repo-local node_modules/.bin.
-    The local lookup goes through ``shutil.which`` with an explicit path so
-    Windows resolves the ``.cmd`` shim (CreateProcess cannot run npm's
-    extensionless POSIX shim — WinError 193) while POSIX keeps the plain one.
-    """
-    yield shutil.which("agent-browser")
-    if extended_path:
-        yield shutil.which("agent-browser", path=extended_path)
-    local_bin_dir = Path(__file__).parent.parent / "node_modules" / ".bin"
-    if local_bin_dir.is_dir():
-        yield shutil.which("agent-browser", path=str(local_bin_dir))
-
-
-def _find_agent_browser(*, validate: bool = True) -> str:
-    """
-    Find the agent-browser CLI executable.
-
-    Checks in order: current PATH, Homebrew/common bin dirs, Hermes-managed
-    node, local node_modules/.bin/, npx fallback, then a lazy install.
-
-    Every candidate is validated with ``agent_browser_runnable`` before it is
-    cached. A bare ``shutil.which`` hit is NOT trusted: agent-browser's npm
-    postinstall re-points a global symlink at our local node_modules binary,
-    which disappears on the next ``hermes update`` and leaves a dangling link
-    that ``which`` still reports but exec fails on (exit 127). Validating lets a
-    dead candidate fall through instead of being cached and killing every
-    browser tool. ``validate=False`` (schema-time check_fn) only tests presence
-    and never caches.
-
-    Raises:
-        FileNotFoundError: If agent-browser is not installed
-    """
-    global _cached_agent_browser, _agent_browser_resolved
-    if _agent_browser_resolved:
-        if _cached_agent_browser is None:
-            raise FileNotFoundError(
-                "agent-browser CLI not found (cached). Install it with: "
-                f"{_browser_install_hint()}\n"
-                "Or ensure npx is available in your PATH."
-            )
-        return _cached_agent_browser
-
-    def _accept(candidate: str) -> str:
-        # _agent_browser_resolved is set at each accept site (not before the
-        # search) so a concurrent reader never sees resolved=True with a None cache.
-        global _cached_agent_browser, _agent_browser_resolved
-        if validate:
-            _cached_agent_browser = candidate
-            _agent_browser_resolved = True
-        return candidate
-
-    ok = agent_browser_runnable if validate else _agent_browser_candidate_present
-    extended_path = _merge_browser_path("")
-    for candidate in _agent_browser_candidates(extended_path):
-        if candidate and ok(candidate):
-            return _accept(candidate)
-
-    # npx fallback (also searches the extended PATH)
-    if _resolve_npx_bin():
-        return _accept(NPX_AGENT_BROWSER_SENTINEL)
-
-    if not validate:
-        raise FileNotFoundError("agent-browser CLI not found")
-
-    # Nothing found — try lazy installation before giving up.
-    try:
-        from hermes_cli.dep_ensure import ensure_dependency
-        if ensure_dependency("browser"):
-            candidates = [
-                shutil.which("agent-browser"),
-                shutil.which("agent-browser", path=extended_path) if extended_path else None,
-                shutil.which("agent-browser", path=str(get_hermes_home() / "node_modules" / ".bin")),
-                shutil.which("agent-browser", path=str(get_hermes_home() / "node" / "bin")),
-                shutil.which("agent-browser", path=str(get_hermes_home() / "node")),
-            ]
-            for recheck in candidates:
-                if recheck and agent_browser_runnable(recheck):
-                    return _accept(recheck)
-    except Exception:
-        pass
-
-    _agent_browser_resolved = True
-    raise FileNotFoundError(
-        "agent-browser CLI not found. Install it with: "
-        f"{_browser_install_hint()}\n"
-        "Or ensure npx is available in your PATH."
-    )
-
-
-def _kill_process_tree(proc: "subprocess.Popen") -> None:
-    """Best-effort kill of *proc* and every descendant it spawned; never raises.
-
-    ``Popen.kill()`` only signals the direct child. npm/npx fork helpers and
-    agent-browser's detached daemon grandchild, which survive a plain kill and
-    keep a capture pipe open so ``communicate()`` never sees EOF — on Windows
-    there is no non-blocking read to poll around that, so the whole tree must
-    go. No grace period: the caller already burned its full timeout waiting.
-    Delegates to :func:`agent.deadline.kill_process_tree` (taskkill /T /F,
-    killpg, plus a psutil sweep that reaches ``setsid``'d descendants) and
-    falls back to :func:`_legacy_kill_process_tree` on any failure.
-    """
-    try:
-        from agent.deadline import kill_process_tree as _deadline_kill_tree
-
-        _deadline_kill_tree(proc.pid)
-    except Exception:
-        _legacy_kill_process_tree(proc)
-
-
-def _legacy_kill_process_tree(proc: "subprocess.Popen") -> None:
-    """Local tree-kill — fallback when agent.deadline is unavailable."""
-    if os.name == "nt":
-        try:
-            subprocess.run(
-                ["taskkill", "/PID", str(proc.pid), "/T", "/F"],
-                check=False,
-                capture_output=True,
-                stdin=subprocess.DEVNULL,
-            )
-        except Exception:
-            pass
-        return
-    # os.killpg/signal.SIGKILL don't exist on Windows; this branch is
-    # POSIX-only (the `os.name == "nt"` check above already returns first
-    # on Windows), but resolve them defensively via getattr anyway so an
-    # accidental future refactor that drops that guard degrades to a plain
-    # kill() instead of AttributeError — same discipline as
-    # tools/mcp_stdio_watchdog.py's _terminate_process_group.
-    killpg = getattr(os, "killpg", None)
-    if killpg is None:  # windows-footgun: ok - non-POSIX fallback
-        try:
-            proc.kill()
-        except Exception:
-            pass
-        return
-    try:
-        pgid = os.getpgid(proc.pid)
-    except (ProcessLookupError, OSError):
-        return
-    sigkill = getattr(signal, "SIGKILL", signal.SIGTERM)
-    for sig in (signal.SIGTERM, sigkill):
-        try:
-            killpg(pgid, sig)
-        except (ProcessLookupError, PermissionError, OSError):
-            return
-
-
-def warm_agent_browser_npx_cache(timeout: float = 60.0) -> bool:
-    """Best-effort pre-fetch of the agent-browser npm package via npx.
-
-    agent-browser resolves lazily via ``npx agent-browser`` (not a root
-    package.json dependency), so the first invocation in a session would pay
-    npx's registry fetch; ``hermes update`` / ``hermes doctor --fix`` call this
-    to warm the cache first. Runs with the credential-scrubbed env every other
-    agent-browser spawn uses (registry-fetched npm code must never see the
-    operator keyring), in its own process group, and tree-kills on timeout so
-    a surviving descendant cannot hold the capture pipe open.
-    Never raises; True only when npx actually exited 0.
-    """
-    npx_bin = _resolve_npx_bin()
-    if not npx_bin:
-        return False
-
-    env = _build_browser_env()
-    env["PATH"] = _merge_browser_path(env.get("PATH", ""))
-
-    popen_kwargs: dict = {
-        "stdout": subprocess.PIPE,
-        "stderr": subprocess.PIPE,
-        "text": True,
-        "env": env,
-        "creationflags": windows_hide_flags(),
-    }
-    if os.name == "posix":
-        popen_kwargs["start_new_session"] = True
-    else:
-        popen_kwargs["creationflags"] |= getattr(subprocess, "CREATE_NEW_PROCESS_GROUP", 0)
-
-    cmd = [
-        npx_bin,
-        # --ignore-scripts: AGENT_BROWSER_NPX_SPEC is a floating ^0.26.0
-        # range, not an exact pin — a compromised future 0.26.x patch must
-        # not get to run its own install-time lifecycle scripts here.
-        "--ignore-scripts",
-        # --prefer-offline: once cached, repeat `hermes update`/`doctor
-        # --fix` runs shouldn't hit the registry just to re-confirm
-        # "latest" is still latest — that would defeat the point of
-        # warming the cache in the first place.
-        "--prefer-offline",
-        "-y",
-        AGENT_BROWSER_NPX_SPEC,
-        "--version",
-    ]
-    try:
-        proc = subprocess.Popen(cmd, stdin=subprocess.DEVNULL, **popen_kwargs)
-    except Exception:
-        return False
-    try:
-        proc.communicate(timeout=timeout)
-        return proc.returncode == 0
-    except subprocess.TimeoutExpired:
-        _kill_process_tree(proc)
-        try:
-            proc.communicate(timeout=5)
-        except Exception:
-            pass
-        return False
-    except Exception:
-        _kill_process_tree(proc)
-        return False
-
 
 from tools.browser_tool_snapshot import (  # noqa: F401
     _store_full_snapshot,
@@ -2595,392 +956,6 @@ from tools.browser_tool_snapshot import (  # noqa: F401
 )
 
 
-def _discard_timed_out_browser_session(
-    task_id: str,
-    session_info: Dict[str, Any],
-    task_socket_dir: str,
-) -> None:
-    """Drop a stuck client generation without losing cloud cleanup state."""
-    with _cleanup_lock:
-        if _active_sessions.get(task_id) is not session_info:
-            return
-        _stop_cdp_supervisor(task_id)
-        if session_info.get("bb_session_id") or session_info.get("cdp_url"):
-            import uuid
-            replacement = dict(session_info)
-            replacement["session_name"] = f"h_{uuid.uuid4().hex[:10]}"
-            replacement.pop("_first_nav", None)
-            _active_sessions[task_id] = replacement
-        else:
-            _active_sessions.pop(task_id, None)
-            _session_last_activity.pop(task_id, None)
-
-        bare_task_id = _bare_task_id_for_session_key(task_id)
-        if _last_active_session_key.get(bare_task_id) == task_id:
-            _last_active_session_key.pop(bare_task_id, None)
-
-    session_name = str(session_info.get("session_name") or "")
-    if session_name:
-        pid_file = os.path.join(task_socket_dir, f"{session_name}.pid")
-        if os.path.isfile(pid_file):
-            try:
-                daemon_pid = int(Path(pid_file).read_text(encoding="utf-8").strip())
-                if not _verify_reapable_browser_daemon(daemon_pid, task_socket_dir, session_name):
-                    return
-                # Tree-kill: the daemon spawns Chromium
-                # children; terminating only the daemon PID leaks the whole
-                # Chromium tree.  agent.deadline.kill_process_tree escalates
-                # SIGTERM → SIGKILL across the tree.
-                from agent import deadline as _deadline
-
-                _deadline.kill_process_tree(daemon_pid)
-            except (ProcessLookupError, ValueError, PermissionError, OSError):
-                logger.debug("Could not kill timed-out browser daemon for %s", session_name)
-                return
-    shutil.rmtree(task_socket_dir, ignore_errors=True)
-
-
-def _read_browser_daemon_pid(task_socket_dir: str, session_name: str) -> Optional[int]:
-    """Read the agent-browser daemon PID for a session (best-effort)."""
-    pid_file = os.path.join(task_socket_dir, f"{session_name}.pid")
-    try:
-        return int(Path(pid_file).read_text(encoding="utf-8").strip())
-    except (OSError, ValueError):
-        return None
-
-
-def _browser_daemon_responsive(task_socket_dir: str, probe_timeout_s: float = 1.0) -> bool:
-    """Cheap liveness probe: connect to the daemon's unix control socket.
-
-    A successful connect proves the accept loop is alive (the command wedged on
-    the page/CDP side, not the daemon). Windows uses named pipes — no probe is
-    possible, so report unresponsive (tree-kill + respawn is the safe recovery).
-    """
-    if os.name == "nt":
-        return False
-    import socket as socket_mod
-
-    if not hasattr(socket_mod, "AF_UNIX"):
-        return False
-    try:
-        entries = os.listdir(task_socket_dir)
-    except OSError:
-        return False
-    sock_paths = [
-        os.path.join(task_socket_dir, e) for e in entries if e.endswith(".sock")
-    ]
-    for sock_path in sock_paths:
-        try:
-            with socket_mod.socket(socket_mod.AF_UNIX, socket_mod.SOCK_STREAM) as s:
-                s.settimeout(probe_timeout_s)
-                s.connect(sock_path)
-                return True
-        except OSError:
-            continue
-    return False
-
-
-def _handle_browser_command_timeout(
-    task_id: str,
-    session_info: Dict[str, Any],
-    task_socket_dir: str,
-) -> None:
-    """Recover session state after a browser command timeout.
-
-    * Cloud / CDP sessions: no local daemon to probe — replace the stuck client
-      generation now (fresh ``session_name``, same ``bb_session_id`` so cloud
-      cleanup still works).
-    * Local daemon alive (PID live, identity-verified, control socket accepts):
-      only the *command* wedged; mark the session suspect and let the next use
-      recycle it via ``ensure_healthy`` → clean ``close`` → fresh session.
-    * Local daemon wedged/dead: it cannot service a clean close and its Chromium
-      children would leak — tree-kill and evict now; the next call respawns.
-
-    Both local branches ``mark_suspect`` first (cheap, lock-free) so the
-    poisoned-cache invariant holds even if eviction races another thread's
-    replacement (the flag then costs one harmless no-op teardown).
-    """
-    if session_info.get("bb_session_id") or session_info.get("cdp_url"):
-        _discard_timed_out_browser_session(task_id, session_info, task_socket_dir)
-        return
-
-    _browser_session_backend(task_id).mark_suspect(
-        "browser command timed out; session may be poisoned"
-    )
-
-    session_name = str(session_info.get("session_name") or "")
-    daemon_pid = _read_browser_daemon_pid(task_socket_dir, session_name) if session_name else None
-    daemon_alive = (
-        daemon_pid is not None
-        and _pid_exists(daemon_pid)
-        and _verify_reapable_browser_daemon(daemon_pid, task_socket_dir, session_name)
-        and _browser_daemon_responsive(task_socket_dir)
-    )
-    if daemon_alive:
-        logger.warning(
-            "browser daemon for %s is alive after command timeout; session "
-            "marked suspect and will be recycled at next use", task_id,
-        )
-        return
-
-    logger.warning(
-        "browser daemon for %s is wedged or dead after command timeout; "
-        "tree-killing and evicting the session", task_id,
-    )
-    _discard_timed_out_browser_session(task_id, session_info, task_socket_dir)
-    # The poisoned entry is gone (evicted, or superseded by a concurrent
-    # replacement discard refused to touch) — either way the cache no longer
-    # holds the timed-out session, so drop the flag: it must not poison a
-    # session created later under the same key.
-    _suspect_browser_sessions.pop(task_id, None)
-
-
-def _pid_exists(pid: int) -> bool:
-    """Best-effort 'is this PID alive' check (signal 0 / psutil on Windows)."""
-    if pid <= 0:
-        return False
-    if os.name == "nt":
-        try:
-            import psutil
-
-            return psutil.pid_exists(pid)
-        except Exception:
-            return False
-    try:
-        os.kill(pid, 0)  # windows-footgun: ok — psutil.pid_exists above handles Windows
-    except ProcessLookupError:
-        return False
-    except PermissionError:
-        return True
-    except OSError:
-        return False
-    return True
-
-
-def _interpret_browser_command_output(command: str, stdout: str, stderr: str, returncode: int) -> Dict[str, Any]:
-    """Turn a finished agent-browser process's output into a result dict.
-
-    Empty stdout with rc=0 is a broken state (stale daemon) and is reported as
-    failure rather than a silent ``{"success": True, "data": {}}`` — except for
-    commands in ``_EMPTY_OK_COMMANDS``. Non-JSON output is an error, except
-    for ``screenshot`` where the saved path is recovered from the prose.
-    """
-    if stderr and stderr.strip():
-        level = logging.WARNING if returncode != 0 else logging.DEBUG
-        logger.log(level, "browser '%s' stderr: %s", command, stderr.strip()[:500])
-
-    stdout_text = stdout.strip()
-    if not stdout_text and returncode == 0 and command not in _EMPTY_OK_COMMANDS:
-        logger.warning("browser '%s' returned empty output (rc=0)", command)
-        return {"success": False, "error": f"Browser command '{command}' returned no output"}
-    if not stdout_text:
-        if returncode != 0:
-            error_msg = stderr.strip() if stderr else f"Command failed with code {returncode}"
-            logger.warning("browser '%s' failed (rc=%s): %s", command, returncode, error_msg[:300])
-            return {"success": False, "error": error_msg}
-        return {"success": True, "data": {}}
-
-    try:
-        parsed = json.loads(stdout_text)
-    except json.JSONDecodeError:
-        raw = stdout_text[:2000]
-        logger.warning("browser '%s' returned non-JSON output (rc=%s): %s",
-                       command, returncode, raw[:500])
-        if command == "screenshot":
-            stderr_text = (stderr or "").strip()
-            combined_text = "\n".join(part for part in [stdout_text, stderr_text] if part)
-            recovered_path = _extract_screenshot_path_from_text(combined_text)
-            if recovered_path and Path(recovered_path).exists():
-                logger.info(
-                    "browser 'screenshot' recovered file from non-JSON output: %s",
-                    recovered_path,
-                )
-                return {"success": True, "data": {"path": recovered_path, "raw": raw}}
-        return {"success": False, "error": f"Non-JSON output from agent-browser for '{command}': {raw}"}
-
-    # Empty snapshot content is a common sign of daemon/CDP issues.
-    if command == "snapshot" and parsed.get("success"):
-        snap_data = parsed.get("data", {})
-        if not snap_data.get("snapshot") and not snap_data.get("refs"):
-            logger.warning("snapshot returned empty content. "
-                           "Possible stale daemon or CDP connection issue. "
-                           "returncode=%s", returncode)
-    return parsed
-
-
-def _run_browser_command(
-    task_id: str,
-    command: str,
-    args: List[str] = None,
-    timeout: Optional[int] = None,
-    _engine_override: Optional[str] = None,
-) -> Dict[str, Any]:
-    """Run one agent-browser CLI command against the task's session; returns its parsed JSON.
-
-    ``timeout=None`` reads ``browser.command_timeout`` (default 30s).
-    ``_engine_override`` forces an engine for this call only (the Lightpanda
-    fallback uses it to retry with Chrome without touching global state).
-    """
-    if timeout is None:
-        timeout = _safe_command_timeout()
-    args = args or []
-
-    # Build the command
-    try:
-        browser_cmd = _find_agent_browser()
-    except FileNotFoundError as e:
-        logger.warning("agent-browser CLI not found: %s", e)
-        return {"success": False, "error": str(e)}
-
-    if _requires_real_termux_browser_install(browser_cmd):
-        error = _termux_browser_install_error()
-        logger.warning("browser command blocked on Termux: %s", error)
-        return {"success": False, "error": error}
-
-    # Local mode with no Chromium on disk: fail fast with an actionable
-    # message instead of hanging for _command_timeout seconds per call.
-    # Skip when engine=lightpanda — LP doesn't need Chromium for navigation.
-    if (
-        _is_local_mode()
-        and not _chromium_installed()
-        and _get_browser_engine() != "lightpanda"
-        and not _maybe_autoinstall_chromium()
-    ):
-        if _running_in_docker():
-            hint = (
-                "Chromium browser is missing. You're running in Docker — pull "
-                "the latest image to get the bundled Chromium: "
-                "docker pull ghcr.io/nousresearch/hermes-agent:latest"
-            )
-        else:
-            hint = (
-                "Chromium browser is missing. Install it with: "
-                "npx agent-browser install --with-deps "
-                "(or: npx playwright install --with-deps chromium)"
-            )
-        logger.warning("browser command blocked: %s", hint)
-        return {"success": False, "error": hint}
-
-    from tools.interrupt import is_interrupted
-    if is_interrupted():
-        return {"success": False, "error": "Interrupted"}
-
-    # Get session info (creates Browserbase session with proxies if needed)
-    try:
-        session_info = _get_session_info(task_id)
-    except Exception as e:
-        logger.warning("Failed to create browser session for task=%s: %s", task_id, e)
-        return {"success": False, "error": f"Failed to create browser session: {str(e)}"}
-    # Cleanup stops the supervisor before closing the backend; keep it stopped.
-    if command != "close" and session_info.get("cdp_url"):
-        _ensure_cdp_supervisor(task_id)
-
-    # Build the command with the appropriate backend flag.
-    # Cloud mode: --cdp <websocket_url> connects to Browserbase.
-    # Local mode: --session <name> launches a local headless Chromium.
-    # The rest of the command (--json, command, args) is identical.
-    if session_info.get("cdp_url"):
-        # Cloud mode — connect to remote Browserbase browser via CDP
-        # IMPORTANT: Do NOT use --session with --cdp. In agent-browser >=0.13,
-        # --session creates a local browser instance and silently ignores --cdp.
-        backend_args = ["--cdp", session_info["cdp_url"]]
-    else:
-        # Local mode — launch Chromium (headless by default, headed when configured)
-        backend_args = ["--session", session_info["session_name"]]
-        if _is_headed_mode():
-            backend_args.append("--headed")
-
-    # Lightpanda engine injection (local mode only, agent-browser v0.25.3+).
-    # Use the resolved session backend rather than global cloud-provider state:
-    # hybrid private-URL routing can create a local sidecar while a cloud
-    # provider remains configured for public URLs.
-    engine = _engine_override or _get_browser_engine()
-    if engine != "auto" and not _is_camofox_mode() and not session_info.get("cdp_url"):
-        backend_args += ["--engine", engine]
-
-    cmd_parts = _agent_browser_argv(browser_cmd) + backend_args + ["--json", command] + args
-
-    try:
-        task_socket_dir = _prepare_session_socket_dir(session_info["session_name"])
-        logger.debug("browser cmd=%s task=%s socket_dir=%s (%d chars)",
-                     command, task_id, task_socket_dir, len(task_socket_dir))
-        browser_env = _agent_browser_command_env(task_socket_dir)
-
-        # Chromium-only launch flags are rejected by Lightpanda. Strip both
-        # the current and legacy variables for Lightpanda commands; explicit
-        # Chrome commands and fallback use the shared Chromium policy.
-        if engine == "lightpanda":
-            _stripped_args = browser_env.pop("AGENT_BROWSER_ARGS", None)
-            _stripped_flags = browser_env.pop("AGENT_BROWSER_CHROME_FLAGS", None)
-            if _stripped_args is not None or _stripped_flags is not None:
-                logger.debug(
-                    "browser: stripped Chromium-only AGENT_BROWSER_ARGS/"
-                    "AGENT_BROWSER_CHROME_FLAGS for Lightpanda command %s "
-                    "(agent-browser rejects them with --engine lightpanda)",
-                    command,
-                )
-        else:
-            _apply_chromium_sandbox_args(browser_env)
-
-        stdout_path = os.path.join(task_socket_dir, f"_stdout_{command}")
-        stderr_path = os.path.join(task_socket_dir, f"_stderr_{command}")
-        proc = _popen_agent_browser(cmd_parts, browser_env, task_socket_dir, command)
-
-        try:
-            proc.wait(timeout=timeout)
-        except subprocess.TimeoutExpired:
-            proc.kill()
-            proc.wait()
-            stdout, stderr = _read_command_output_files(stdout_path, stderr_path)
-            _unlink_command_output_files(stdout_path, stderr_path)
-            _handle_browser_command_timeout(task_id, session_info, task_socket_dir)
-            if stderr and stderr.strip():
-                logger.warning(
-                    "browser '%s' stderr after timeout: %s",
-                    command,
-                    stderr.strip()[:500],
-                )
-            logger.warning("browser '%s' timed out after %ds (task=%s, socket_dir=%s)",
-                           command, timeout, task_id, task_socket_dir)
-            result = {
-                "success": False,
-                "error": _format_browser_timeout_error(command, timeout, stdout, stderr),
-            }
-            # Fall through to fallback check below
-        else:
-            with open(stdout_path, "r", encoding="utf-8") as f:
-                stdout = f.read()
-            with open(stderr_path, "r", encoding="utf-8") as f:
-                stderr = f.read()
-            _unlink_command_output_files(stdout_path, stderr_path)
-            result = _interpret_browser_command_output(command, stdout, stderr, proc.returncode)
-
-    except Exception as e:
-        logger.warning("browser '%s' exception: %s", command, e, exc_info=True)
-        result = {"success": False, "error": str(e)}
-
-    # --- Lightpanda automatic Chrome fallback ---
-    # If engine is lightpanda and the result looks broken, retry with Chrome.
-    # This runs for ALL exit paths (timeout, empty, non-JSON, nonzero rc, parsed).
-    fallback_reason = _lightpanda_fallback_reason(engine, command, result)
-    if fallback_reason:
-        logger.info(
-            "Lightpanda fallback: retrying '%s' with Chrome (task=%s): %s",
-            command,
-            task_id,
-            fallback_reason,
-        )
-        # For screenshots, use the dedicated Chrome fallback helper
-        # (spins up a separate Chrome session to the same URL).
-        if command == "screenshot":
-            fallback_result = _chrome_fallback_screenshot(task_id, args or [], timeout)
-        else:
-            fallback_result = _run_chrome_fallback_command(task_id, command, args, timeout)
-        return _annotate_lightpanda_fallback(fallback_result, fallback_reason)
-
-    return result
-
-
 # ============================================================================
 # Browser Tool Functions
 # ============================================================================
@@ -3064,8 +1039,7 @@ def _post_redirect_block(nav_session_key: str, url: str, final_url: str, auto_lo
     if _is_always_blocked_url(final_url):
         _run_browser_command(nav_session_key, "open", ["about:blank"], timeout=10)
         return json.dumps({
-            "success": False,
-            "error": "Blocked: redirect landed on a cloud metadata endpoint",
+            "success": False, "error": "Blocked: redirect landed on a cloud metadata endpoint"
         })
     if (
         not _is_local_backend()
@@ -3075,8 +1049,7 @@ def _post_redirect_block(nav_session_key: str, url: str, final_url: str, auto_lo
     ):
         _run_browser_command(nav_session_key, "open", ["about:blank"], timeout=10)
         return json.dumps({
-            "success": False,
-            "error": "Blocked: redirect landed on a private/internal address",
+            "success": False, "error": "Blocked: redirect landed on a private/internal address"
         })
     return None
 
@@ -3146,16 +1119,12 @@ def browser_navigate(url: str, task_id: Optional[str] = None) -> str:
         _maybe_start_recording(nav_session_key)
 
     result = _run_browser_command(
-        nav_session_key,
-        "open",
-        [url],
-        timeout=_get_open_command_timeout(first_open=is_first_nav),
+        nav_session_key, "open", [url], timeout=_get_open_command_timeout(first_open=is_first_nav)
     )
 
     if not result.get("success"):
         return json.dumps({
-            "success": False,
-            "error": result.get("error", "Navigation failed")
+            "success": False, "error": result.get("error", "Navigation failed")
         }, ensure_ascii=False)
 
     data = result.get("data", {})
@@ -3167,9 +1136,7 @@ def browser_navigate(url: str, task_id: Optional[str] = None) -> str:
         return blocked
 
     response = {
-        "success": True,
-        "url": final_url,
-        "title": title
+        "success": True, "url": final_url, "title": title
     }
     # Auditability: stamp navigations that ran on the user's real-profile
     # copy-browser so usage is visible in the tool result.
@@ -3209,9 +1176,7 @@ def browser_navigate(url: str, task_id: Optional[str] = None) -> str:
 
 
 def browser_snapshot(
-    full: bool = False,
-    task_id: Optional[str] = None,
-    user_task: Optional[str] = None
+    full: bool = False, task_id: Optional[str] = None, user_task: Optional[str] = None
 ) -> str:
     """Text snapshot of the page's accessibility tree (compact unless ``full``).
 
@@ -3271,12 +1236,16 @@ def browser_snapshot(
             logger.debug("supervisor snapshot merge failed: %s", _sv_exc)
 
         return json.dumps(response, ensure_ascii=False)
-    else:
-        response = {
-            "success": False,
-            "error": result.get("error", "Failed to get snapshot")
-        }
-        return json.dumps(_copy_fallback_warning(response, result), ensure_ascii=False)
+    return _failed_response(result, "Failed to get snapshot")
+
+
+def _json_with_fallback(response: Dict[str, Any], result: Dict[str, Any]) -> str:
+    """``json.dumps`` of ``response`` with the Lightpanda fallback metadata copied from ``result``."""
+    return json.dumps(_copy_fallback_warning(response, result), ensure_ascii=False)
+
+
+def _failed_response(result: Dict[str, Any], default_error: str) -> str:
+    return _json_with_fallback({"success": False, "error": result.get("error", default_error)}, result)
 
 
 def _tool_response(result: Dict[str, Any], ok: Dict[str, Any], default_error: str) -> str:
@@ -3286,11 +1255,9 @@ def _tool_response(result: Dict[str, Any], ok: Dict[str, Any], default_error: st
     "error": result.error or default_error}``. Lightpanda fallback metadata
     is copied onto either shape.
     """
-    if result.get("success"):
-        response = {"success": True, **ok}
-    else:
-        response = {"success": False, "error": result.get("error", default_error)}
-    return json.dumps(_copy_fallback_warning(response, result), ensure_ascii=False)
+    if not result.get("success"):
+        return _failed_response(result, default_error)
+    return _json_with_fallback({"success": True, **ok}, result)
 
 
 def browser_click(ref: str, task_id: Optional[str] = None) -> str:
@@ -3327,8 +1294,7 @@ def browser_type(ref: str, text: str, task_id: Optional[str] = None) -> str:
     result = _run_browser_command(effective_task_id, "fill", [ref, text])
 
     from agent.display import (
-        redact_browser_typed_text_for_display,
-        redact_tool_args_for_display,
+        redact_browser_typed_text_for_display, redact_tool_args_for_display
     )
 
     # Typed text goes through the secret-pattern redactor so API keys / tokens
@@ -3348,8 +1314,7 @@ def browser_scroll(direction: str, task_id: Optional[str] = None) -> str:
     """Scroll the page ``direction`` ("up"/"down") by about half a viewport."""
     if direction not in {"up", "down"}:
         return json.dumps({
-            "success": False,
-            "error": f"Invalid direction '{direction}'. Use 'up' or 'down'."
+            "success": False, "error": f"Invalid direction '{direction}'. Use 'up' or 'down'."
         }, ensure_ascii=False)
 
     # Single scroll with a pixel amount (~half a viewport) instead of 5x subprocess calls.
@@ -3378,21 +1343,15 @@ def browser_back(task_id: Optional[str] = None) -> str:
     effective_task_id = _last_session_key(task_id or "default")
     result = _run_browser_command(effective_task_id, "back", [])
 
-    if result.get("success") and _eval_ssrf_guard_active(effective_task_id):
+    if result.get("success"):
         # History can land on a private/internal/cloud-metadata address the
         # navigate preflight never saw (earlier redirect chain, manipulated
         # client-side history). Re-check post-navigation like every other
         # content-returning entry point — the floor fires for every backend.
-        _blocked_url = _current_page_private_url(effective_task_id)
-        if _blocked_url:
-            return json.dumps({
-                "success": False,
-                "error": (
-                    "Blocked: page URL targets a private or internal address "
-                    f"({_blocked_url}). Browser history navigation (back) "
-                    "landed on this address."
-                ),
-            }, ensure_ascii=False)
+        blocked = _blocked_private_page(
+            effective_task_id, "Browser history navigation (back) landed on this address.")
+        if blocked is not None:
+            return blocked
     return _tool_response(result, {"url": result.get("data", {}).get("url", "")}, "Failed to go back")
 
 
@@ -3410,47 +1369,39 @@ def browser_press(key: str, task_id: Optional[str] = None) -> str:
     return _tool_response(result, {"pressed": key}, f"Failed to press {key}")
 
 
-def _blocked_private_page_action(effective_task_id: str, action: str) -> Optional[str]:
-    """Return a blocked payload when an unsafe cloud page would receive input."""
-    if not _eval_ssrf_guard_active(effective_task_id):
-        return None
-    blocked_url = _current_page_private_url(effective_task_id)
-    if not blocked_url:
-        return None
+def _blocked_private_page_json(blocked_url: str, why: str) -> str:
+    """Refusal payload for a page whose URL targets a private/internal address."""
     return json.dumps({
         "success": False,
-        "error": (
-            "Blocked: page URL targets a private or internal address "
-            f"({blocked_url}). Refusing to {action} on this page in this "
-            "browser mode."
-        ),
+        "error": f"Blocked: page URL targets a private or internal address ({blocked_url}). {why}",
     }, ensure_ascii=False)
 
 
-def _blocked_private_page_json(blocked_url: str) -> str:
-    """Blocked payload for content-returning tools whose page was eval-navigated private."""
-    return json.dumps({
-        "success": False,
-        "error": (
-            "Blocked: page URL targets a private or internal address "
-            f"({blocked_url}). This may have been caused by a "
-            "JavaScript navigation via browser_console."
-        ),
-    }, ensure_ascii=False)
-
-
-def _blocked_private_page_content(effective_task_id: str) -> Optional[str]:
+def _blocked_private_page(effective_task_id: str, why: str) -> Optional[str]:
     """Blocked payload when the SSRF guard is active and the current page is private, else None.
 
-    Sibling of the snapshot/vision/eval/get_images guards: after any eval that
-    may have changed ``location.href`` to a private address, returning page
-    content would expose it. Fail-open on probe failure (see
-    ``_current_page_private_url``).
+    Fail-open on probe failure (see ``_current_page_private_url``).
     """
     if not _eval_ssrf_guard_active(effective_task_id):
         return None
     blocked_url = _current_page_private_url(effective_task_id)
-    return _blocked_private_page_json(blocked_url) if blocked_url else None
+    return _blocked_private_page_json(blocked_url, why) if blocked_url else None
+
+
+def _blocked_private_page_action(effective_task_id: str, action: str) -> Optional[str]:
+    """Return a blocked payload when an unsafe cloud page would receive input."""
+    return _blocked_private_page(
+        effective_task_id, f"Refusing to {action} on this page in this browser mode.")
+
+
+_EVAL_NAVIGATED_WHY = "This may have been caused by a JavaScript navigation via browser_console."
+
+
+def _blocked_private_page_content(effective_task_id: str) -> Optional[str]:
+    """Content-returning tools (snapshot/vision/eval/get_images): after any eval that
+    may have changed ``location.href`` to a private address, returning page content
+    would expose it."""
+    return _blocked_private_page(effective_task_id, _EVAL_NAVIGATED_WHY)
 
 
 def browser_console(clear: bool = False, expression: Optional[str] = None, task_id: Optional[str] = None) -> str:
@@ -3493,8 +1444,7 @@ def browser_console(clear: bool = False, expression: Optional[str] = None, task_
     if errors_result.get("success"):
         for err in errors_result.get("data", {}).get("errors", []):
             errors.append({
-                "message": _redact_browser_output(err.get("message", "")),
-                "source": "exception",
+                "message": _redact_browser_output(err.get("message", "")), "source": "exception"
             })
 
     response = {
@@ -3573,8 +1523,7 @@ def _eval_supervisor_fast_path(effective_task_id: str, expression: str) -> Optio
         if "supervisor" not in err.lower():
             return json.dumps({"success": False, "error": err}, ensure_ascii=False)
         logger.debug(
-            "browser_eval: supervisor path unavailable (%s), falling back to subprocess",
-            err,
+            "browser_eval: supervisor path unavailable (%s), falling back to subprocess", err
         )
     except ImportError:
         pass
@@ -3674,7 +1623,7 @@ def _camofox_eval(expression: str, task_id: Optional[str] = None) -> str:
         if _eval_ssrf_guard_active(task_id or "default"):
             _blocked_url = _camofox_current_page_private_url(tab_id, user_id)
             if _blocked_url:
-                return _blocked_private_page_json(_blocked_url)
+                return _blocked_private_page_json(_blocked_url, _EVAL_NAVIGATED_WHY)
 
         return json.dumps({
             "success": True,
@@ -3778,26 +1727,12 @@ def browser_get_images(task_id: Optional[str] = None) -> str:
             else:
                 images = raw_result
 
-            response = {
-                "success": True,
-                "images": _redact_browser_output(images),
-                "count": len(images)
-            }
-            return json.dumps(_copy_fallback_warning(response, result), ensure_ascii=False)
+            return _json_with_fallback(
+                {"success": True, "images": _redact_browser_output(images), "count": len(images)}, result)
         except json.JSONDecodeError:
-            response = {
-                "success": True,
-                "images": [],
-                "count": 0,
-                "warning": "Could not parse image data"
-            }
-            return json.dumps(_copy_fallback_warning(response, result), ensure_ascii=False)
-    else:
-        response = {
-            "success": False,
-            "error": result.get("error", "Failed to get images")
-        }
-        return json.dumps(_copy_fallback_warning(response, result), ensure_ascii=False)
+            return _json_with_fallback(
+                {"success": True, "images": [], "count": 0, "warning": "Could not parse image data"}, result)
+    return _failed_response(result, "Failed to get images")
 
 
 _LP_VISION_FALLBACK_REASON = (
@@ -3805,167 +1740,12 @@ _LP_VISION_FALLBACK_REASON = (
 )
 
 
-def _vision_mode_label() -> str:
-    _cp = _get_cloud_provider()
-    return "local" if _cp is None else f"cloud ({_cp.provider_name()})"
-
-
-def _lightpanda_vision_preroute(
-    effective_task_id: str, annotate: bool, screenshot_path: Path,
-) -> Tuple[bool, Optional[str], Path]:
-    """Capture the vision screenshot through the Chrome fallback when Lightpanda is the engine.
-
-    Lightpanda has no graphical renderer, so the normal path would fail with a
-    CDP error or return a placeholder PNG. Returns ``(prerouted, fallback_warning,
-    screenshot_path)``; on fallback failure ``prerouted`` is False and the caller
-    takes the normal screenshot path (forcing Chrome) so ``_run_browser_command``
-    still produces the standard fallback metadata/error.
-    """
-    engine = _get_browser_engine()
-    if engine != "lightpanda" or not _should_inject_engine(engine):
-        return False, None, screenshot_path
-    logger.debug("browser_vision: pre-routing screenshot to Chrome (engine=lightpanda)")
-    screenshot_args = ["--annotate"] if annotate else []
-    fb_result = _chrome_fallback_screenshot(effective_task_id, screenshot_args, _get_command_timeout())
-    fb_result = _annotate_lightpanda_fallback(fb_result, _LP_VISION_FALLBACK_REASON)
-    if not fb_result.get("success"):
-        logger.warning("Lightpanda Chrome fallback vision screenshot failed: %s", fb_result.get("error"))
-        return False, None, screenshot_path
-    fb_path = fb_result.get("data", {}).get("path", "")
-    if fb_path and os.path.exists(fb_path):
-        import uuid as uuid_mod
-        from hermes_constants import get_hermes_dir
-
-        screenshots_dir = get_hermes_dir("cache/screenshots", "browser_screenshots")
-        screenshots_dir.mkdir(parents=True, exist_ok=True)
-        persistent_path = screenshots_dir / f"browser_screenshot_{uuid_mod.uuid4().hex}.png"
-        shutil.copy2(fb_path, persistent_path)
-        screenshot_path = persistent_path
-    return True, fb_result.get("fallback_warning"), screenshot_path
-
-
-def _native_vision_result(
-    screenshot_path: Path, question: str, annotate: bool,
-    result: Dict[str, Any], lp_fallback_warning: Optional[str],
-) -> Dict[str, Any]:
-    """Multimodal tool-result envelope: the main model inspects the pixels itself.
-
-    History-reuse cap: this embed is baked into the tool result and re-sent on
-    every later turn, exactly like vision_analyze's native path — apply the same
-    proactive resize so full-res screenshots can't enter immutable history
-    uncapped. The helper's stat/dimension quick-estimate skips the resize when
-    already under both caps; without Pillow it fails open to the raw bytes.
-    """
-    from tools.vision_tools import (
-        _EMBED_MAX_DIMENSION,
-        _EMBED_TARGET_BYTES,
-        _build_native_vision_tool_result,
-        _resize_image_for_vision,
-    )
-
-    data_url = _resize_image_for_vision(
-        screenshot_path,
-        mime_type="image/png",
-        max_base64_bytes=_EMBED_TARGET_BYTES,
-        max_dimension=_EMBED_MAX_DIMENSION,
-        force_jpeg=True,
-    )
-    native_result = _build_native_vision_tool_result(
-        image_url=str(screenshot_path),
-        question=question,
-        image_data_url=data_url,
-        image_size_bytes=screenshot_path.stat().st_size,
-    )
-    meta = native_result.setdefault("meta", {})
-    meta["screenshot_path"] = str(screenshot_path)
-    if lp_fallback_warning:
-        meta["fallback_warning"] = lp_fallback_warning
-    if annotate and result.get("data", {}).get("annotations"):
-        meta["annotations"] = result["data"]["annotations"]
-    native_result["text_summary"] = (
-        f"{native_result.get('text_summary', '')} "
-        f"Screenshot path: {screenshot_path}"
-    ).strip()
-    return native_result
-
-
-def _analyze_screenshot_with_aux_llm(screenshot_path: Path, question: str) -> str:
-    """One-shot aux vision-LLM analysis (not baked into history), secret-redacted.
-
-    Encodes at full resolution; on a size-related provider rejection the image
-    is downscaled once and retried. Timeout/temperature come from
-    ``auxiliary.vision.*`` — local vision models (llama.cpp, ollama) can take
-    well over 30s, so the default timeout is generous.
-    """
-    import base64
-
-    vision_prompt = (
-        f"You are analyzing a screenshot of a web browser.\n\n"
-        f"User's question: {question}\n\n"
-        f"Provide a detailed and helpful answer based on what you see in the screenshot. "
-        f"If there are interactive elements, describe them. If there are verification challenges "
-        f"or CAPTCHAs, describe what type they are and what action might be needed. "
-        f"Focus on answering the user's specific question."
-    )
-    _screenshot_bytes = screenshot_path.read_bytes()
-    _screenshot_b64 = base64.b64encode(_screenshot_bytes).decode("ascii")
-    data_url = f"data:image/png;base64,{_screenshot_b64}"
-    vision_model = _get_vision_model()
-    logger.debug("browser_vision: analysing screenshot (%d bytes)",
-                 len(_screenshot_bytes))
-
-    vision_timeout = 120.0
-    vision_temperature = 0.1
-    try:
-        from hermes_cli.config import load_config
-        _vision_cfg = cfg_get(load_config(), "auxiliary", "vision", default={})
-        _vt = _vision_cfg.get("timeout")
-        if _vt is not None:
-            vision_timeout = float(_vt)
-        _vtemp = _vision_cfg.get("temperature")
-        if _vtemp is not None:
-            vision_temperature = float(_vtemp)
-    except Exception:
-        pass
-
-    call_kwargs = {
-        "task": "vision",
-        "messages": [
-            {
-                "role": "user",
-                "content": [
-                    {"type": "text", "text": vision_prompt},
-                    {"type": "image_url", "image_url": {"url": data_url}},
-                ],
-            }
-        ],
-        "temperature": vision_temperature,
-        "timeout": vision_timeout,
-    }
-    if vision_model:
-        call_kwargs["model"] = vision_model
-    try:
-        response = _lazy_call_llm(**call_kwargs)
-    except Exception as _api_err:
-        from tools.vision_tools import (
-            _is_image_size_error, _resize_image_for_vision, _RESIZE_TARGET_BYTES,
-        )
-        if not (_is_image_size_error(_api_err) and len(data_url) > _RESIZE_TARGET_BYTES):
-            raise
-        logger.info(
-            "Vision API rejected screenshot (%.1f MB); "
-            "auto-resizing to ~%.0f MB and retrying...",
-            len(data_url) / (1024 * 1024),
-            _RESIZE_TARGET_BYTES / (1024 * 1024),
-        )
-        data_url = _resize_image_for_vision(screenshot_path, mime_type="image/png")
-        call_kwargs["messages"][0]["content"][1]["image_url"]["url"] = data_url
-        response = _lazy_call_llm(**call_kwargs)
-
-    analysis = (response.choices[0].message.content or "").strip()
-    # Redact secrets the vision LLM may have read from the screenshot.
-    from agent.redact import redact_sensitive_text
-    return redact_sensitive_text(analysis)
+from tools.browser_tool_vision import (  # noqa: F401  (re-exported; tests patch tools.browser_tool.<name>)
+    _vision_mode_label,
+    _lightpanda_vision_preroute,
+    _native_vision_result,
+    _analyze_screenshot_with_aux_llm,
+)
 
 
 def browser_vision(question: str, annotate: bool = False, task_id: Optional[str] = None) -> Union[str, Dict[str, Any]]:
@@ -4020,11 +1800,10 @@ def browser_vision(question: str, annotate: bool = False, task_id: Optional[str]
 
         if not result.get("success"):
             error_detail = result.get("error", "Unknown error")
-            error_response = {
+            return _json_with_fallback({
                 "success": False,
-                "error": f"Failed to take screenshot ({_vision_mode_label()} mode): {error_detail}"
-            }
-            return json.dumps(_copy_fallback_warning(error_response, result), ensure_ascii=False)
+                "error": f"Failed to take screenshot ({_vision_mode_label()} mode): {error_detail}",
+            }, result)
 
         actual_screenshot_path = result.get("data", {}).get("path")
         if actual_screenshot_path:
@@ -4073,277 +1852,10 @@ def browser_vision(question: str, annotate: bool = False, task_id: Optional[str]
         return json.dumps(error_info, ensure_ascii=False)
 
 
-def _cleanup_old_screenshots(screenshots_dir, max_age_hours=24):
-    """Remove browser screenshots older than max_age_hours to prevent disk bloat.
-
-    Throttled to run at most once per hour per directory to avoid repeated
-    scans on screenshot-heavy workflows.
-    """
-    key = str(screenshots_dir)
-    now = time.time()
-    if now - _last_screenshot_cleanup_by_dir.get(key, 0.0) < 3600:
-        return
-    _last_screenshot_cleanup_by_dir[key] = now
-
-    try:
-        cutoff = time.time() - (max_age_hours * 3600)
-        for f in screenshots_dir.glob("browser_screenshot_*.png"):
-            try:
-                if f.stat().st_mtime < cutoff:
-                    f.unlink()
-            except Exception as e:
-                logger.debug("Failed to clean old screenshot %s: %s", f, e)
-    except Exception as e:
-        logger.debug("Screenshot cleanup error (non-critical): %s", e)
-
-
-def _cleanup_old_recordings(max_age_hours=72):
-    """Remove browser recordings older than max_age_hours to prevent disk bloat."""
-    try:
-        hermes_home = get_hermes_home()
-        recordings_dir = hermes_home / "browser_recordings"
-        if not recordings_dir.exists():
-            return
-        cutoff = time.time() - (max_age_hours * 3600)
-        for f in recordings_dir.glob("session_*.webm"):
-            try:
-                if f.stat().st_mtime < cutoff:
-                    f.unlink()
-            except Exception as e:
-                logger.debug("Failed to clean old recording %s: %s", f, e)
-    except Exception as e:
-        logger.debug("Recording cleanup error (non-critical): %s", e)
-
-
 # ============================================================================
 # Cleanup and Management Functions
 # ============================================================================
 
-def _drop_last_active_binding(task_id: str) -> None:
-    """Drop stale last-active ownership after cleaning ``task_id``.
-
-    Cleaning a bare task drops its binding; cleaning a sidecar drops the binding
-    only if that sidecar was still the recorded owner — so a later
-    click/snapshot can't resurrect a cleaned sidecar on about:blank while a
-    primary-session binding is preserved.
-    """
-    if _is_local_sidecar_key(task_id):
-        bare_task_id = _bare_task_id_for_session_key(task_id)
-        if _last_active_session_key.get(bare_task_id) == task_id:
-            _last_active_session_key.pop(bare_task_id, None)
-    else:
-        _last_active_session_key.pop(task_id, None)
-
-
-def cleanup_browser(task_id: Optional[str] = None) -> None:
-    """Clean up browser session(s) for a task (task completion / inactivity timeout).
-
-    A bare task id reaps BOTH the primary session and any hybrid local sidecar
-    spawned for it; a key already carrying ``::local`` (inactivity loop) reaps
-    only that one.
-    """
-    if task_id is None:
-        task_id = "default"
-
-    session_keys = [task_id]
-    if not _is_local_sidecar_key(task_id):
-        sidecar_key = f"{task_id}{_LOCAL_SUFFIX}"
-        with _cleanup_lock:
-            if sidecar_key in _active_sessions:
-                session_keys.append(sidecar_key)
-
-    for session_key in session_keys:
-        _cleanup_single_browser_session(session_key)
-    _drop_last_active_binding(task_id)
-
-
-def _kill_verified_daemon(socket_dir: str, session_name: str) -> bool:
-    """Tree-kill the daemon recorded in ``<socket_dir>/<session>.pid`` if it is verifiably ours.
-
-    The .pid file lives in a world-writable temp dir and PIDs recycle: the
-    process must pass ``_verify_reapable_browser_daemon`` and have a start-time
-    fingerprint (so the kill refuses if the PID is swapped between check and
-    kill). Returns True when a kill was issued. Never raises.
-    """
-    pid_file = os.path.join(socket_dir, f"{session_name}.pid")
-    if not os.path.isfile(pid_file):
-        return False
-    try:
-        from tools.process_registry import ProcessRegistry
-        daemon_pid = int(Path(pid_file).read_text(encoding="utf-8").strip())
-        if not _verify_reapable_browser_daemon(daemon_pid, socket_dir, session_name):
-            logger.debug(
-                "Skipped daemon kill for %s: pid %s failed identity "
-                "verification", session_name, daemon_pid)
-            return False
-        from gateway.status import get_process_start_time
-        daemon_start = get_process_start_time(daemon_pid)
-        if daemon_start is None:
-            logger.debug(
-                "Skipped daemon kill for %s: no start-time "
-                "fingerprint for pid %s", session_name, daemon_pid)
-            return False
-        ProcessRegistry._terminate_host_pid(daemon_pid, daemon_start)
-        logger.debug("Killed daemon pid %s for %s", daemon_pid, session_name)
-        return True
-    except (ProcessLookupError, ValueError, PermissionError, OSError):
-        logger.debug("Could not kill daemon pid for %s (already dead or inaccessible)", session_name)
-        return False
-
-
-def _release_session_resources(task_id: str, session_info: Dict[str, Any]) -> None:
-    """Untrack ``task_id``, close its cloud provider session, kill its daemon.
-
-    The unconditional tail of ``_cleanup_single_browser_session``; also the
-    whole of the janitor's force-reap path, which skips the polite
-    agent-browser/Camofox ``close`` that kept failing but must still release
-    the cloud session and the local Chromium.
-    """
-    bb_session_id = session_info.get("bb_session_id", "unknown")
-    with _cleanup_lock:
-        _active_sessions.pop(task_id, None)
-        _session_last_activity.pop(task_id, None)
-        _session_owner_homes.pop(task_id, None)
-        _cleanup_failures.pop(task_id, None)
-
-    # Cloud mode only — local sidecars have bb_session_id=None.
-    if bb_session_id:
-        provider = _get_cloud_provider()
-        if provider is not None:
-            try:
-                provider.close_session(bb_session_id)
-            except Exception as e:
-                logger.warning("Could not close cloud browser session: %s", e)
-
-    session_name = session_info.get("session_name", "")
-    if session_name:
-        socket_dir = os.path.join(_socket_safe_tmpdir(), f"agent-browser-{session_name}")
-        if os.path.exists(socket_dir):
-            _kill_verified_daemon(socket_dir, session_name)
-            shutil.rmtree(socket_dir, ignore_errors=True)
-
-
-def _force_reap_browser_session(task_id: str) -> None:
-    """Janitor last resort after repeated cleanup failures.
-
-    Skips the ``close`` round-trips that keep failing and goes straight to
-    ``_release_session_resources`` (cloud close + daemon kill + untrack).
-    """
-    _stop_cdp_supervisor(task_id)
-    with _cleanup_lock:
-        session_info = _active_sessions.get(task_id)
-        _session_last_activity.pop(task_id, None)
-        _recording_sessions.discard(task_id)
-    if session_info:
-        _release_session_resources(task_id, session_info)
-    _drop_last_active_binding(task_id)
-
-
-def _cleanup_single_browser_session(task_id: str) -> None:
-    """Internal: reap a single browser session by its exact session key."""
-    # Stop the CDP supervisor for this task FIRST so we close our WebSocket
-    # before the backend tears down the underlying CDP endpoint.
-    _stop_cdp_supervisor(task_id)
-
-    # Also clean up Camofox session if running in Camofox mode.
-    # Skip full close when managed persistence is enabled — the browser
-    # profile (and its session cookies) must survive across agent tasks.
-    # The inactivity reaper still frees idle resources.
-    if _is_camofox_mode():
-        try:
-            from tools.browser_camofox import camofox_close, camofox_soft_cleanup
-            if not camofox_soft_cleanup(task_id):
-                camofox_close(task_id)
-        except Exception as e:
-            logger.debug("Camofox cleanup for task %s: %s", task_id, e)
-
-    logger.debug("cleanup_browser called for task_id: %s", task_id)
-    logger.debug("Active sessions: %s", list(_active_sessions.keys()))
-
-    # Check if session exists (under lock), but don't remove yet -
-    # _run_browser_command needs it to build the close command.
-    with _cleanup_lock:
-        session_info = _active_sessions.get(task_id)
-
-    if session_info:
-        bb_session_id = session_info.get("bb_session_id", "unknown")
-        logger.debug("Found session for task %s: bb_session_id=%s", task_id, bb_session_id)
-
-        # Stop auto-recording before closing (saves the file)
-        _maybe_stop_recording(task_id)
-
-        # A Lightpanda session is a process Hermes spawned itself (Browser
-        # Use mode); there is no agent-browser daemon to send ``close`` to.
-        # An expired cloud CDP URL cannot accept an agent-browser close command.
-        # Avoid feeding it back through _get_session_info(), which would try to
-        # renew the session recursively while cleanup is still in progress.
-        if (session_info.get("features") or {}).get("lightpanda"):
-            try:
-                from tools.browser_lightpanda import stop_lightpanda
-
-                stop_lightpanda(session_info.get("session_name", ""))
-            except Exception as e:
-                logger.warning("lightpanda stop failed for task %s: %s", task_id, e)
-        elif _session_has_expired(session_info):
-            logger.debug(
-                "Skipping agent-browser close for expired session %s",
-                task_id,
-            )
-        else:
-            try:
-                _run_browser_command(task_id, "close", [], timeout=10)
-                logger.debug(
-                    "agent-browser close command completed for task %s",
-                    task_id,
-                )
-            except Exception as e:
-                logger.warning("agent-browser close failed for task %s: %s", task_id, e)
-
-        _release_session_resources(task_id, session_info)
-
-        logger.debug("Removed task %s from active sessions", task_id)
-    else:
-        logger.debug("No active session found for task_id: %s", task_id)
-
-
-def cleanup_all_browsers() -> None:
-    """
-    Clean up all active browser sessions.
-
-    Useful for cleanup on shutdown.
-    """
-    with _cleanup_lock:
-        task_ids = list(_active_sessions.keys())
-    for task_id in task_ids:
-        cleanup_browser(task_id)
-
-    # Tear down CDP supervisors for all tasks so background threads exit.
-    try:
-        from tools.browser_supervisor import SUPERVISOR_REGISTRY  # type: ignore[import-not-found]
-        SUPERVISOR_REGISTRY.stop_all()
-    except Exception:
-        pass
-
-    # Reset cached lookups so they are re-evaluated on next use.
-    global _cached_agent_browser, _agent_browser_resolved
-    global _cached_command_timeout, _command_timeout_resolved
-    global _cached_snapshot_threshold, _snapshot_threshold_resolved
-    global _cached_chromium_installed
-    global _cached_browser_engine, _browser_engine_resolved
-    _cached_agent_browser = None
-    _agent_browser_resolved = False
-    _discover_homebrew_node_dirs.cache_clear()
-    # Flip the resolved flag BEFORE nulling the cache so a concurrent
-    # reader never sees ``resolved=True`` with ``cache=None``.
-    _command_timeout_resolved = False
-    _cached_command_timeout = None
-    _snapshot_threshold_resolved = False
-    _cached_snapshot_threshold = None
-    _cached_chromium_installed = None
-    global _chromium_autoinstall_attempted
-    _chromium_autoinstall_attempted = False
-    _cached_browser_engine = None
-    _browser_engine_resolved = False
 
 # ============================================================================
 # Requirements Check
@@ -4354,286 +1866,17 @@ def cleanup_all_browsers() -> None:
 _cached_chromium_installed: Optional[bool] = None
 
 
-def _chromium_search_roots() -> List[str]:
-    """Directories to scan for a Chromium / headless-shell build, in the order
-    agent-browser and Playwright probe them: ``PLAYWRIGHT_BROWSERS_PATH``, then
-    Playwright's per-OS default cache."""
-    roots: List[str] = []
-    env_path = os.environ.get("PLAYWRIGHT_BROWSERS_PATH", "").strip()
-    if env_path and env_path != "0":
-        roots.append(env_path)
-    home = os.path.expanduser("~")
-    roots.append(os.path.join(home, ".cache", "ms-playwright"))
-    if sys.platform == "darwin":
-        roots.append(os.path.join(home, "Library", "Caches", "ms-playwright"))
-    if sys.platform == "win32":
-        local = os.environ.get("LOCALAPPDATA") or os.path.join(
-            home, "AppData", "Local"
-        )
-        roots.append(os.path.join(local, "ms-playwright"))
-    return roots
-
-
-def _chromium_installed() -> bool:
-    """Return True when a usable Chromium (or headless-shell) build is on disk.
-
-    Checks ``AGENT_BROWSER_EXECUTABLE_PATH``, then system Chrome/Chromium on
-    PATH, then Playwright's cache (``chromium-*`` / ``chromium_headless_shell-*``
-    dirs). Without a binary the CLI hangs on first use until the command
-    timeout fires, so the tool must not be advertised.
-    """
-    global _cached_chromium_installed
-    if _cached_chromium_installed is not None:
-        return _cached_chromium_installed
-
-    # 1. AGENT_BROWSER_EXECUTABLE_PATH — explicit user-configured browser
-    ab_path = os.environ.get("AGENT_BROWSER_EXECUTABLE_PATH", "").strip()
-    if ab_path and (os.path.isfile(ab_path) or shutil.which(ab_path)):
-        _cached_chromium_installed = True
-        return True
-
-    # 2. System Chrome/Chromium in PATH (common names)
-    system_chrome = (
-        shutil.which("google-chrome")
-        or shutil.which("chromium")
-        or shutil.which("chromium-browser")
-        or shutil.which("chrome")
-    )
-    if system_chrome:
-        _cached_chromium_installed = True
-        return True
-
-    # 3. Playwright browser cache (legacy — chromium-* / chromium_headless_shell-* dirs)
-    for root in _chromium_search_roots():
-        if not root or not os.path.isdir(root):
-            continue
-        try:
-            entries = os.listdir(root)
-        except OSError:
-            continue
-        # Playwright names them ``chromium-<build>`` and
-        # ``chromium_headless_shell-<build>``; agent-browser accepts either.
-        for entry in entries:
-            if entry.startswith("chromium-") or entry.startswith(
-                "chromium_headless_shell-"
-            ):
-                _cached_chromium_installed = True
-                return True
-
-    _cached_chromium_installed = False
-    return False
-
-
 # One-shot per process: a 170MB download that fails (or is slow) must not be
 # retried on every browser call. Reset by _reset_browser_caches() for tests.
 _chromium_autoinstall_attempted = False
 
 
-def _maybe_autoinstall_chromium() -> bool:
-    """Best-effort, gated download of the Chromium *binary* on local cold start.
-
-    Binary only (``agent-browser install``), never ``--with-deps`` — that shells
-    ``apt`` and needs root, so missing system libraries stay a user action.
-    Gated by ``security.allow_lazy_installs``, skipped in Docker (Chromium ships
-    in the image), attempted once per process. True only when Chromium is
-    present afterwards.
-    """
-    global _chromium_autoinstall_attempted
-    if _chromium_autoinstall_attempted:
-        return _chromium_installed()
-    _chromium_autoinstall_attempted = True
-
-    if _running_in_docker():
-        return False
-
-    from tools.lazy_deps import _allow_lazy_installs
-    if not _allow_lazy_installs():
-        return False
-
-    try:
-        browser_cmd = _find_agent_browser()
-    except FileNotFoundError:
-        return False
-
-    if _is_npx_agent_browser_sentinel(browser_cmd):
-        install_cmd = [
-            _resolve_npx_bin() or "npx", "--ignore-scripts", "-y", AGENT_BROWSER_NPX_SPEC, "install",
-        ]
-    else:
-        install_cmd = [browser_cmd, "install"]
-
-    logger.info(
-        "browser: Chromium missing — auto-installing the browser binary "
-        "(one-time ~170MB; disable via security.allow_lazy_installs)"
-    )
-    try:
-        proc = subprocess.run(
-            install_cmd,
-            capture_output=True,
-            text=True, encoding='utf-8', errors='replace',
-            timeout=600,
-            env=_build_browser_env(),
-        )
-    except (OSError, subprocess.SubprocessError) as e:
-        logger.warning("browser: Chromium auto-install failed to start: %s", e)
-        return False
-
-    if proc.returncode != 0:
-        tail = (proc.stderr or proc.stdout or "").strip()[-300:]
-        logger.warning(
-            "browser: Chromium auto-install exited %s: %s", proc.returncode, tail
-        )
-        return False
-
-    global _cached_chromium_installed
-    _cached_chromium_installed = None
-    return _chromium_installed()
-
-
-def _running_in_docker() -> bool:
-    """Best-effort detection of whether we're inside a Docker container."""
-    if os.path.exists("/.dockerenv"):
-        return True
-    try:
-        with open("/proc/1/cgroup", "rt", encoding="utf-8") as fp:
-            return "docker" in fp.read()
-    except OSError:
-        return False
-
-
-def check_browser_requirements() -> bool:
-    """Whether the browser tools should be advertised.
-
-    Local mode needs the ``agent-browser`` CLI plus a Chromium build (except
-    Lightpanda-only text workflows); cloud mode needs the CLI plus provider
-    credentials (the provider hosts its own Chromium).
-    """
-    # Browser Use CLI backend — browser_exec replaces the whole browser_*
-    # surface (including browser_cdp/browser_dialog, whose check_fns funnel
-    # through here), so hide these tools from the model.
-    if _is_browser_use_cli_mode():
-        return False
-
-    # Camofox backend — only needs the server URL, no agent-browser CLI
-    if _is_camofox_mode():
-        return True
-
-    # CDP override mode can connect to an existing remote/local browser endpoint
-    # without requiring the local agent-browser binary on PATH.
-    # Raw (no-I/O) check: this runs during tool-schema assembly at startup,
-    # where a stale endpoint must not cost a blocking HTTP probe.
-    if _get_cdp_override_raw():
-        return True
-
-    # The agent-browser CLI is required for local launch and cloud-provider flows.
-    # Tool-schema assembly runs during Desktop startup; do not execute
-    # ``agent-browser --version`` here, because Windows .cmd shims route through
-    # cmd.exe and can flash a console before the user invokes any browser tool.
-    # Actual browser execution paths still validate the candidate before use.
-    try:
-        browser_cmd = _find_agent_browser(validate=False)
-    except FileNotFoundError:
-        return False
-
-    # On Termux, the bare npx fallback is too fragile to treat as a satisfied
-    # local browser dependency. Require a real install (global or local) so the
-    # browser tool is not advertised as available when it will likely fail on
-    # first use.
-    if _requires_real_termux_browser_install(browser_cmd):
-        return False
-
-    # In cloud mode, also require provider credentials. Cloud browsers
-    # don't need a local Chromium binary.
-    provider = _get_cloud_provider()
-    if provider is not None:
-        return provider.is_configured()
-
-    # Local mode with Lightpanda can provide text/navigation tools without a
-    # local Chromium install. Chrome fallback, screenshots, and browser_vision
-    # will still return actionable Chromium install errors if invoked.
-    if _using_lightpanda_engine():
-        return True
-
-    # Local Chrome mode: agent-browser needs a Chromium build on disk. Without
-    # it the CLI hangs on first use until the command timeout fires.
-    return _chromium_installed()
-
-
-def check_browser_vision_requirements() -> bool:
-    """Advertise ``browser_vision`` only with BOTH a working browser AND a vision
-    backend — otherwise it fails at call time with a cryptic provider error."""
-    if not check_browser_requirements():
-        return False
-    try:
-        from tools.vision_tools import check_vision_requirements
-    except ImportError:
-        return False
-    return check_vision_requirements()
-
-
-# ============================================================================
-# Module Test
-# ============================================================================
-
-if __name__ == "__main__":
-    """
-    Simple test/demo when run directly
-    """
-    print("🌐 Browser Tool Module")
-    print("=" * 40)
-
-    _cp = _get_cloud_provider()
-    mode = "local" if _cp is None else f"cloud ({_cp.provider_name()})"
-    print(f"   Mode: {mode}")
-
-    # Check requirements
-    if check_browser_requirements():
-        print("✅ All requirements met")
-    else:
-        print("❌ Missing requirements:")
-        try:
-            browser_cmd = _find_agent_browser()
-            if _requires_real_termux_browser_install(browser_cmd):
-                print("   - bare npx fallback found (insufficient on Termux local mode)")
-                print(f"     Install: {_browser_install_hint()}")
-            elif _cp is None and not _chromium_installed():
-                print("   - Chromium browser binary not found")
-                searched = ", ".join(_chromium_search_roots()) or "(no candidate paths)"
-                print(f"     Searched: {searched}")
-                if _running_in_docker():
-                    print(
-                        "     Docker: pull the latest image — the current one "
-                        "predates the bundled Chromium install"
-                    )
-                    print("       docker pull ghcr.io/nousresearch/hermes-agent:latest")
-                else:
-                    print("     Install it with:")
-                    print("       npx agent-browser install --with-deps")
-                    print("     Or:  npx playwright install --with-deps chromium")
-        except FileNotFoundError:
-            print("   - agent-browser CLI not found")
-            print(f"     Install: {_browser_install_hint()}")
-        if _cp is not None and not _cp.is_configured():
-            print(f"   - {_cp.provider_name()} credentials not configured")
-            print("   Tip: set browser.cloud_provider to 'local' to use free local mode instead")
-
-    print("\n📋 Available Browser Tools:")
-    for schema in BROWSER_TOOL_SCHEMAS:
-        print(f"  🔹 {schema['name']}: {schema['description'][:60]}...")
-
-    print("\n💡 Usage:")
-    print("  from tools.browser_tool import browser_navigate, browser_snapshot")
-    print("  result = browser_navigate('https://example.com', task_id='my_task')")
-    print("  snapshot = browser_snapshot(task_id='my_task')")
-
-
 # ---------------------------------------------------------------------------
 # Registry
 # ---------------------------------------------------------------------------
 from tools.registry import registry, tool_error
 from tools.browser_extension_router import (
-    extension_controller_available,
-    routed_browser_handler,
+    extension_controller_available, routed_browser_handler
 )
 
 _BROWSER_SCHEMA_MAP = {s["name"]: s for s in BROWSER_TOOL_SCHEMAS}
@@ -4642,8 +1885,7 @@ _BROWSER_SCHEMA_MAP = {s["name"]: s for s in BROWSER_TOOL_SCHEMAS}
 def _browser_router_kw(kw: dict) -> dict:
     """Identity kwargs forwarded to the extension router wrapper."""
     return {
-        "task_id": kw.get("task_id"),
-        "session_id": kw.get("session_id"),
+        "task_id": kw.get("task_id"), "session_id": kw.get("session_id")
     }
 
 
@@ -4652,163 +1894,65 @@ def check_browser_routed_requirements(action: str = "browser_snapshot") -> bool:
     return check_browser_requirements() or extension_controller_available(action)
 
 
-def check_browser_navigate_requirements() -> bool:
-    return check_browser_routed_requirements("browser_navigate")
-
-
-def check_browser_snapshot_requirements() -> bool:
-    return check_browser_routed_requirements("browser_snapshot")
-
-
-def check_browser_click_requirements() -> bool:
-    return check_browser_routed_requirements("browser_click")
-
-
-def check_browser_type_requirements() -> bool:
-    return check_browser_routed_requirements("browser_type")
-
-
-def check_browser_scroll_requirements() -> bool:
-    return check_browser_routed_requirements("browser_scroll")
-
-
-def check_browser_back_requirements() -> bool:
-    return check_browser_routed_requirements("browser_back")
-
-
-def check_browser_press_requirements() -> bool:
-    return check_browser_routed_requirements("browser_press")
-
-
-registry.register(
-    name="browser_navigate",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_navigate"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_navigate",
-        args,
-        fallback=lambda: browser_navigate(url=args.get("url", ""), task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_navigate_requirements,
-    emoji="🌐",
-)
-registry.register(
-    name="browser_snapshot",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_snapshot"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_snapshot",
-        args,
-        fallback=lambda: browser_snapshot(
-            full=args.get("full", False), task_id=kw.get("task_id"), user_task=kw.get("user_task")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_snapshot_requirements,
-    emoji="📸",
-)
-registry.register(
-    name="browser_click",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_click"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_click",
-        args,
-        fallback=lambda: browser_click(ref=args.get("ref", ""), task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_click_requirements,
-    emoji="👆",
-)
-registry.register(
-    name="browser_type",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_type"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_type",
-        args,
-        fallback=lambda: browser_type(ref=args.get("ref", ""), text=args.get("text", ""), task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_type_requirements,
-    emoji="⌨️",
-)
-registry.register(
-    name="browser_scroll",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_scroll"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_scroll",
-        args,
-        fallback=lambda: browser_scroll(direction=args.get("direction", "down"), task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_scroll_requirements,
-    emoji="📜",
-)
-registry.register(
-    name="browser_back",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_back"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_back",
-        args,
-        fallback=lambda: browser_back(task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_back_requirements,
-    emoji="◀️",
-)
-registry.register(
-    name="browser_press",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_press"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_press",
-        args,
-        fallback=lambda: browser_press(key=args.get("key", ""), task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_press_requirements,
-    emoji="⌨️",
+# (tool name, emoji, availability gate, fallback call) — the routed-through-
+# extension tools use the per-action gate; get_images/console/vision keep the
+# plain requirement checks.  ``_fallback`` receives (args, kw).
+_BROWSER_TOOL_TABLE = (
+    ("browser_navigate", "🌐", None,
+     lambda args, kw: browser_navigate(url=args.get("url", ""), task_id=kw.get("task_id"))),
+    ("browser_snapshot", "📸", None,
+     lambda args, kw: browser_snapshot(
+         full=args.get("full", False), task_id=kw.get("task_id"), user_task=kw.get("user_task"))),
+    ("browser_click", "👆", None,
+     lambda args, kw: browser_click(ref=args.get("ref", ""), task_id=kw.get("task_id"))),
+    ("browser_type", "⌨️", None,
+     lambda args, kw: browser_type(ref=args.get("ref", ""), text=args.get("text", ""), task_id=kw.get("task_id"))),
+    ("browser_scroll", "📜", None,
+     lambda args, kw: browser_scroll(direction=args.get("direction", "down"), task_id=kw.get("task_id"))),
+    ("browser_back", "◀️", None,
+     lambda args, kw: browser_back(task_id=kw.get("task_id"))),
+    ("browser_press", "⌨️", None,
+     lambda args, kw: browser_press(key=args.get("key", ""), task_id=kw.get("task_id"))),
+    ("browser_get_images", "🖼️", check_browser_requirements,
+     lambda args, kw: browser_get_images(task_id=kw.get("task_id"))),
+    ("browser_vision", "👁️", check_browser_vision_requirements,
+     lambda args, kw: browser_vision(
+         question=args.get("question", ""), annotate=args.get("annotate", False), task_id=kw.get("task_id"))),
+    ("browser_console", "🖥️", check_browser_requirements,
+     lambda args, kw: browser_console(
+         clear=args.get("clear", False), expression=args.get("expression"), task_id=kw.get("task_id"))),
 )
 
-registry.register(
-    name="browser_get_images",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_get_images"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_get_images",
-        args,
-        fallback=lambda: browser_get_images(task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_requirements,
-    emoji="🖼️",
-)
-registry.register(
-    name="browser_vision",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_vision"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_vision",
-        args,
-        fallback=lambda: browser_vision(question=args.get("question", ""), annotate=args.get("annotate", False), task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_vision_requirements,
-    emoji="👁️",
-)
-registry.register(
-    name="browser_console",
-    toolset="browser",
-    schema=_BROWSER_SCHEMA_MAP["browser_console"],
-    handler=lambda args, **kw: routed_browser_handler(
-        "browser_console",
-        args,
-        fallback=lambda: browser_console(clear=args.get("clear", False), expression=args.get("expression"), task_id=kw.get("task_id")),
-        **_browser_router_kw(kw),
-    ),
-    check_fn=check_browser_requirements,
-    emoji="🖥️",
-)
+
+def _routed_check_fn(name: str):
+    """Per-action availability gate (a named function, as the registry expects)."""
+    def check() -> bool:
+        return check_browser_routed_requirements(name)
+    check.__name__ = check.__qualname__ = f"check_{name}_requirements"
+    return check
+
+
+def _routed_handler(name: str, fallback):
+    def handler(args, **kw):
+        return routed_browser_handler(name, args, fallback=lambda: fallback(args, kw), **_browser_router_kw(kw))
+    return handler
+
+
+# Legacy per-tool gate names (tests + external callers).
+check_browser_navigate_requirements = _routed_check_fn("browser_navigate")
+check_browser_snapshot_requirements = _routed_check_fn("browser_snapshot")
+check_browser_click_requirements = _routed_check_fn("browser_click")
+check_browser_type_requirements = _routed_check_fn("browser_type")
+check_browser_scroll_requirements = _routed_check_fn("browser_scroll")
+check_browser_back_requirements = _routed_check_fn("browser_back")
+check_browser_press_requirements = _routed_check_fn("browser_press")
+
+for _name, _emoji, _check_fn, _fallback in _BROWSER_TOOL_TABLE:
+    registry.register(
+        name=_name,
+        toolset="browser",
+        schema=_BROWSER_SCHEMA_MAP[_name],
+        handler=_routed_handler(_name, _fallback),
+        check_fn=_check_fn or globals()[f"check_{_name}_requirements"],
+        emoji=_emoji,
+    )
diff --git a/tools/browser_tool_cdp.py b/tools/browser_tool_cdp.py
new file mode 100644
index 0000000000..520ad23864
--- /dev/null
+++ b/tools/browser_tool_cdp.py
@@ -0,0 +1,188 @@
+"""User-supplied CDP endpoint resolution (browser.cdp_url / real-profile), dialog-policy config and the per-task CDP supervisor lifecycle.
+
+Split out of ``tools/browser_tool.py``; every name is re-imported there so
+``tools.browser_tool.<name>`` keeps resolving (and monkeypatching). Origin
+symbols and module state are read/written through ``_bt`` (the origin module,
+resolved per call by :func:`tools.browser_tool_origin.origin_module`) so
+``patch("tools.browser_tool.X")`` is honoured and no import cycle exists.
+"""
+
+import os
+from typing import Tuple
+
+from tools.browser_tool_origin import origin_module as _origin
+
+
+def _resolve_cdp_override(cdp_url: str) -> str:
+    """Normalize a user-supplied CDP endpoint into a concrete websocket URL.
+
+    Full ``ws://.../devtools/browser/...`` endpoints pass through; HTTP
+    discovery roots and bare ``ws://host:port`` are resolved via
+    ``/json/version`` → ``webSocketDebuggerUrl`` (falls back to the raw value
+    with a warning if discovery fails).
+    """
+    _bt = _origin()
+    raw = (cdp_url or "").strip()
+    if not raw:
+        return ""
+
+    lowered = raw.lower()
+    if "/devtools/browser/" in lowered:
+        return raw
+
+    discovery_url = raw
+    if lowered.startswith(("ws://", "wss://")):
+        if raw.count(":") == 2 and raw.rstrip("/").rsplit(":", 1)[-1].isdigit() and "/" not in raw.split(":", 2)[-1]:
+            discovery_url = ("http://" if lowered.startswith("ws://") else "https://") + raw.split("://", 1)[1]
+        else:
+            return raw
+
+    if discovery_url.lower().endswith("/json/version"):
+        version_url = discovery_url
+    else:
+        version_url = discovery_url.rstrip("/") + "/json/version"
+
+    try:
+        import requests  # lazy — shared module object, test patches still apply
+
+        response = requests.get(version_url, timeout=10)
+        response.raise_for_status()
+        payload = response.json()
+    except Exception as exc:
+        _bt.logger.warning(
+            "Failed to resolve CDP endpoint %s via %s: %s",
+            _bt._sanitize_url_for_logs(raw),
+            _bt._sanitize_url_for_logs(version_url),
+            _bt._sanitize_url_for_logs(exc),
+        )
+        return raw
+
+    ws_url = str(payload.get("webSocketDebuggerUrl") or "").strip()
+    if ws_url:
+        _bt.logger.info(
+            "Resolved CDP endpoint %s -> %s",
+            _bt._sanitize_url_for_logs(raw),
+            _bt._sanitize_url_for_logs(ws_url),
+        )
+        return ws_url
+
+    _bt.logger.warning(
+        "CDP discovery at %s did not return webSocketDebuggerUrl; using raw endpoint",
+        _bt._sanitize_url_for_logs(version_url),
+    )
+    return raw
+
+
+def _get_cdp_override_raw() -> str:
+    """Return the *configured* CDP override without any network I/O.
+
+    Precedence: ``BROWSER_CDP_URL`` env (live ``/browser connect`` override),
+    then ``browser.cdp_url`` in config.yaml. Callers that only need to know
+    *whether* an override exists (check_fn gates, ``_is_local_mode`` /
+    ``_is_local_backend``, ``hermes doctor``) MUST use this, not
+    :func:`_get_cdp_override`: that one does a 10s HTTP discovery, and a stale
+    ``cdp_url`` pointing at a dead Chrome would stall every startup's schema
+    build with no error — no side effects during schema build.
+    """
+    _bt = _origin()
+    env_override = os.environ.get("BROWSER_CDP_URL", "").strip()
+    if env_override:
+        return env_override
+    return _bt._browser_cfg(
+        "cdp_url", "", lambda v: str(v or "").strip(), "browser.cdp_url from config"
+    )
+
+
+def _get_cdp_override() -> str:
+    """Return the resolved CDP URL override, or "" (skips cloud AND local launch).
+
+    May perform an HTTP ``/json/version`` discovery request — only call on
+    paths about to *connect* (session creation, supervisor attach); pure
+    is-it-configured gates must use :func:`_get_cdp_override_raw`.
+    """
+    _bt = _origin()
+    raw = _bt._get_cdp_override_raw()
+    if not raw:
+        return ""
+    return _bt._resolve_cdp_override(raw)
+
+
+def _get_dialog_policy_config() -> Tuple[str, float]:
+    """Read ``browser.dialog_policy`` + ``browser.dialog_timeout_s`` from config.
+
+    Returns a ``(policy, timeout_s)`` tuple, falling back to the supervisor's
+    defaults when keys are absent or invalid.
+    """
+    # Defer imports so browser_tool can be imported in minimal environments.
+    _bt = _origin()
+    from tools.browser_supervisor import (
+        DEFAULT_DIALOG_POLICY, DEFAULT_DIALOG_TIMEOUT_S, _VALID_POLICIES
+    )
+
+    try:
+        from hermes_cli.config import read_raw_config
+
+        cfg = read_raw_config()
+        browser_cfg = cfg.get("browser", {}) if isinstance(cfg, dict) else {}
+        if not isinstance(browser_cfg, dict):
+            return DEFAULT_DIALOG_POLICY, DEFAULT_DIALOG_TIMEOUT_S
+        policy = str(browser_cfg.get("dialog_policy") or DEFAULT_DIALOG_POLICY)
+        if policy not in _VALID_POLICIES:
+            _bt.logger.debug("Invalid browser.dialog_policy=%r; using default", policy)
+            policy = DEFAULT_DIALOG_POLICY
+        timeout_raw = browser_cfg.get("dialog_timeout_s")
+        try:
+            timeout_s = float(timeout_raw) if timeout_raw is not None else DEFAULT_DIALOG_TIMEOUT_S
+            if timeout_s <= 0:
+                timeout_s = DEFAULT_DIALOG_TIMEOUT_S
+        except (TypeError, ValueError):
+            timeout_s = DEFAULT_DIALOG_TIMEOUT_S
+        return policy, timeout_s
+    except Exception:
+        return DEFAULT_DIALOG_POLICY, DEFAULT_DIALOG_TIMEOUT_S
+
+
+def _ensure_cdp_supervisor(task_id: str) -> None:
+    """Start a CDP supervisor for ``task_id`` if an endpoint is reachable.
+
+    Idempotent (``SupervisorRegistry.get_or_start`` skips an existing
+    ``(task_id, cdp_url)`` and restarts on URL change), so safe on every
+    navigate / ``/browser connect``. URL precedence: the CDP override, then the
+    session's own ``cdp_url`` (cloud providers). Swallows all errors — a failed
+    attach must not break the session; snapshots just lack
+    ``pending_dialogs`` / ``frame_tree``.
+    """
+    _bt = _origin()
+    cdp_url = _bt._get_cdp_override()
+    if not cdp_url:
+        # Fallback: active session may carry a per-session CDP URL from a
+        # cloud provider (Browserbase sets this).
+        with _bt._cleanup_lock:
+            session_info = _bt._active_sessions.get(task_id, {})
+        maybe = str(session_info.get("cdp_url") or "")
+        if maybe:
+            cdp_url = _bt._resolve_cdp_override(maybe)
+    if not cdp_url:
+        return
+    try:
+        from tools.browser_supervisor import SUPERVISOR_REGISTRY  # type: ignore[import-not-found]
+
+        policy, timeout_s = _bt._get_dialog_policy_config()
+        SUPERVISOR_REGISTRY.get_or_start(
+            task_id=task_id, cdp_url=cdp_url, dialog_policy=policy, dialog_timeout_s=timeout_s
+        )
+    except Exception as exc:
+        _bt.logger.debug(
+            "CDP supervisor attach for task=%s failed (non-fatal): %s", task_id, exc
+        )
+
+
+def _stop_cdp_supervisor(task_id: str) -> None:
+    """Stop the CDP supervisor for ``task_id`` if one exists. No-op otherwise."""
+    _bt = _origin()
+    try:
+        from tools.browser_supervisor import SUPERVISOR_REGISTRY  # type: ignore[import-not-found]
+
+        SUPERVISOR_REGISTRY.stop(task_id)
+    except Exception as exc:
+        _bt.logger.debug("CDP supervisor stop for task=%s failed (non-fatal): %s", task_id, exc)
diff --git a/tools/browser_tool_cloud.py b/tools/browser_tool_cloud.py
new file mode 100644
index 0000000000..7621b8308d
--- /dev/null
+++ b/tools/browser_tool_cloud.py
@@ -0,0 +1,368 @@
+"""Cloud browser provider resolution (explicit browser.cloud_provider, auto-detect, per-profile cache), backend/engine selection and headed-mode flags.
+
+Split out of ``tools/browser_tool.py``; every name is re-imported there so
+``tools.browser_tool.<name>`` keeps resolving (and monkeypatching). Origin
+symbols and module state are read/written through ``_bt`` (the origin module,
+resolved per call by :func:`tools.browser_tool_origin.origin_module`) so
+``patch("tools.browser_tool.X")`` is honoured and no import cycle exists.
+"""
+
+from __future__ import annotations
+
+import os
+from typing import Optional
+
+from agent.browser_provider import BrowserProvider as CloudBrowserProvider
+from tools.browser_tool_origin import origin_module as _origin
+
+
+def _is_legacy_provider_registry_overridden() -> bool:
+    """True when a test has patched ``_PROVIDER_REGISTRY`` to a custom value.
+
+    Each registered value is compared by identity against the canonical class
+    in ``_DEFAULT_PROVIDER_REGISTRY`` (extra keys count too); adding a built-in
+    provider only requires extending that default dict.
+    """
+    _bt = _origin()
+    try:
+        for key, default_cls in _bt._DEFAULT_PROVIDER_REGISTRY.items():
+            if _bt._PROVIDER_REGISTRY.get(key) is not default_cls:
+                return True
+        # Extra keys not in the default registry → also an override.
+        return len(_bt._PROVIDER_REGISTRY) != len(_bt._DEFAULT_PROVIDER_REGISTRY)
+    except Exception:
+        return False
+
+
+def _ensure_browser_plugins_loaded() -> None:
+    """Idempotently trigger plugin discovery so the browser registry is populated.
+
+    ``model_tools`` normally does this as an import side effect, but
+    ``_get_cloud_provider`` is also reached from standalone scripts and test
+    harnesses that never import it; cheap on repeat calls.
+    """
+    _bt = _origin()
+    try:
+        from hermes_cli.plugins import _ensure_plugins_discovered
+
+        _ensure_plugins_discovered()
+    except Exception as exc:
+        _bt.logger.debug("Browser plugin discovery failed (non-fatal): %s", exc)
+
+
+def _get_cloud_provider() -> Optional[CloudBrowserProvider]:
+    """Return the provider cached for the active Hermes profile."""
+    _bt = _origin()
+
+    scope = _bt.hermes_home_key()
+    with _bt._cloud_provider_cache_lock:
+        # Tests and legacy reset paths clear the boolean. Treat that as a full
+        # reset even if a previous scoped resolution remains mirrored here.
+        if not _bt._cloud_provider_resolved:
+            _bt._cached_cloud_provider_scope = None
+            _bt._cached_cloud_providers.clear()
+        while True:
+            before_generation = _bt._browser_registry_generation(scope=scope)
+            cache_key = (scope, before_generation)
+            if cache_key in _bt._cached_cloud_providers:
+                _bt._cached_cloud_provider = _bt._cached_cloud_providers[cache_key]
+                _bt._cloud_provider_resolved = True
+                _bt._cached_cloud_provider_scope = scope
+                return _bt._cached_cloud_provider
+
+            _bt._cached_cloud_provider = None
+            _bt._cloud_provider_resolved = False
+            resolved = _bt._resolve_cloud_provider_uncached()
+            after_generation = _bt._browser_registry_generation(scope=scope)
+            if before_generation != after_generation:
+                # A force reload replaced/unloaded this profile's provider
+                # while resolution was in progress. Discard the stale result
+                # and resolve against the new registry generation.
+                continue
+            if _bt._cloud_provider_resolved:
+                _bt._cached_cloud_provider_scope = scope
+                for stale_key in [
+                    key for key in _bt._cached_cloud_providers if key[0] == scope
+                ]:
+                    _bt._cached_cloud_providers.pop(stale_key, None)
+                _bt._cached_cloud_providers[cache_key] = resolved
+            return resolved
+
+
+def _instantiate_explicit_cloud_provider(provider_key: str) -> Optional[CloudBrowserProvider]:
+    """Build the provider named by ``browser.cloud_provider``.
+
+    Test fixtures that patch ``_PROVIDER_REGISTRY`` drive the legacy dict;
+    otherwise the plugin registry is consulted (after idempotent discovery).
+    Strict selection: a stored-but-unregistered name raises ``ValueError``
+    (never a silent reroute to auto-detect). Any other instantiation error is
+    logged and yields None so the next call retries.
+    """
+    _bt = _origin()
+    try:
+        if _bt._is_legacy_provider_registry_overridden():
+            factory = _bt._PROVIDER_REGISTRY.get(provider_key)
+            resolved = factory() if factory is not None else None
+        else:
+            _bt._ensure_browser_plugins_loaded()
+            resolved = _bt._registry_get_browser_provider(provider_key)
+        if resolved is None:
+            from tools.tool_backend_helpers import selection_error
+
+            raise ValueError(selection_error(
+                "browser",
+                f"'{provider_key}'",
+                "no registered browser plugin has that name (install "
+                "the corresponding plugin or fix the config key "
+                "spelling)",
+            ))
+        return resolved
+    except ValueError:
+        raise
+    except Exception:
+        _bt.logger.warning(
+            "Failed to instantiate explicit cloud_provider %r; will retry on next call",
+            provider_key,
+            exc_info=True,
+        )
+        return None
+
+
+def _autodetect_cloud_provider() -> Optional[CloudBrowserProvider]:
+    """Auto-detect: Browser Use (managed Nous gateway or API key), then Browserbase.
+
+    Uses the legacy class names bound on this module so tests that
+    ``monkeypatch.setattr(browser_tool, "BrowserUseProvider", ...)`` keep
+    driving this branch. Third-party plugins are intentionally NOT reachable
+    from auto-detect — only via explicit ``browser.cloud_provider: <name>``.
+    Never raises (a failure must not poison the cache).
+    """
+    _bt = _origin()
+    try:
+        for cls in (_bt.BrowserUseProvider, _bt.BrowserbaseProvider):
+            fallback_provider = cls()
+            if fallback_provider.is_configured():
+                return fallback_provider
+    except Exception:  # pragma: no cover - defensive: never poison cache
+        _bt.logger.debug("Cloud provider auto-detect failed", exc_info=True)
+    return None
+
+
+def _resolve_cloud_provider_uncached() -> Optional[CloudBrowserProvider]:
+    """Return the configured cloud browser provider, or None for local mode.
+
+    Reads ``browser.cloud_provider`` and pins the result in the cache only when
+    it is definitive (explicit ``local``/``camofox``, or a resolved provider).
+    Explicit selection routes through :mod:`agent.browser_registry` so
+    third-party plugins participate; auto-detect (only when no selection was
+    ever written) walks Browser Use then Browserbase. A transient None
+    (unreadable config, missing credentials) is NOT cached so it can self-heal.
+    """
+    _bt = _origin()
+
+    resolved: Optional[CloudBrowserProvider] = None
+    provider_key = None
+    try:
+        from hermes_cli.config import read_raw_config
+        browser_cfg = read_raw_config().get("browser", {})
+        if isinstance(browser_cfg, dict) and "cloud_provider" in browser_cfg:
+            provider_key = _bt.normalize_browser_cloud_provider(browser_cfg.get("cloud_provider"))
+            if provider_key in ("local", "camofox"):
+                # Camofox runs through the built-in browser tools, not a cloud provider.
+                _bt._cached_cloud_provider = None
+                _bt._cloud_provider_resolved = True
+                return None
+            if provider_key == "nous":
+                # Managed "Nous Subscription" is serviced by the Browser Use provider.
+                provider_key = "browser-use"
+        if provider_key:
+            resolved = _bt._instantiate_explicit_cloud_provider(provider_key)
+            if resolved is None:
+                return None
+    except ValueError:
+        raise
+    except Exception as e:
+        # Config may be temporarily unreadable; still try auto-detect so
+        # env-based / managed-gateway credentials can resolve. Don't pin cache.
+        _bt.logger.debug("Could not read cloud_provider from config: %s", e)
+
+    if resolved is None and provider_key is None:
+        resolved = _bt._autodetect_cloud_provider()
+    if resolved is None:
+        return None
+
+    _bt._cached_cloud_provider = resolved
+    _bt._cloud_provider_resolved = True
+    return _bt._cached_cloud_provider
+
+
+def _is_local_mode() -> bool:
+    """Return True when the browser tool will use a local browser backend."""
+    _bt = _origin()
+    if _bt._get_cdp_override_raw():
+        return False
+    return _bt._get_cloud_provider() is None
+
+
+def _is_local_backend() -> bool:
+    """Return True when the browser runs locally AND the terminal is also local.
+
+    SSRF protection only matters when the browser can reach networks the user's
+    terminal cannot: cloud backends, and a local browser paired with a
+    containerized terminal (docker/modal/daytona/ssh/singularity). A CDP
+    override is never trusted as local (that Chrome may live off-host) and MUST
+    be checked before the Camofox short-circuit so Camofox + override still
+    fails the local check; ``_is_local_mode`` treats overrides the same way —
+    keep the two in agreement.
+    """
+    _bt = _origin()
+    if _bt._get_cdp_override_raw():
+        return False
+    if _bt._is_camofox_mode():
+        return True
+    if _bt._get_cloud_provider() is not None:
+        return False
+    # Scope-aware: under gateway multiplexing the routed profile's terminal
+    # backend lives in the per-turn terminal scope, not the process env.
+    from tools.terminal_scope import terminal_env
+
+    terminal_backend = terminal_env("TERMINAL_ENV", "local").strip().lower()
+    return terminal_backend in ("local", "")
+
+
+def _get_browser_engine() -> str:
+    """Return the browser engine: ``auto`` (no ``--engine`` flag), ``lightpanda`` or ``chrome``.
+
+    ``browser.engine`` first, then ``AGENT_BROWSER_ENGINE``, then ``auto``;
+    cached. Lightpanda is much faster on navigation but has no graphical
+    renderer (no screenshots).
+    """
+    _bt = _origin()
+    if _bt._browser_engine_resolved:
+        return _bt._cached_browser_engine
+
+    _bt._browser_engine_resolved = True
+    # Config file takes priority; env var only if config didn't set a value.
+    _bt._cached_browser_engine = _bt._browser_cfg(
+        "engine", "auto",
+        lambda v: str(v).strip().lower() if v and str(v).strip() else "auto",
+        "browser.engine from config",
+    )
+    if _bt._cached_browser_engine == "auto":
+        env_val = os.environ.get("AGENT_BROWSER_ENGINE", "").strip().lower()
+        if env_val:
+            _bt._cached_browser_engine = env_val
+
+    # Validate: agent-browser only accepts "chrome" and "lightpanda".
+    _VALID_ENGINES = {"auto", "lightpanda", "chrome"}
+    if _bt._cached_browser_engine not in _VALID_ENGINES:
+        _bt.logger.warning(
+            "Unknown browser engine %r (valid: %s), falling back to 'auto'",
+            _bt._cached_browser_engine, ", ".join(sorted(_VALID_ENGINES)),
+        )
+        _bt._cached_browser_engine = "auto"
+
+    return _bt._cached_browser_engine
+
+
+def _is_headed_mode() -> bool:
+    """Return True when the browser should launch in headed (visible) mode.
+
+    Reads ``config["browser"]["headed"]`` with ``AGENT_BROWSER_HEADED`` env
+    var as fallback.  Result is cached after the first call.
+    """
+    _bt = _origin()
+    if _bt._headed_mode_resolved:
+        return _bt._cached_headed_mode  # type: ignore[return-value]
+
+    _bt._headed_mode_resolved = True
+    _bt._cached_headed_mode = _bt._browser_cfg(
+        "headed", False,
+        lambda v: False if v is None else str(v).strip().lower() in ("true", "1", "yes"),
+        "browser.headed from config",
+    )
+    if not _bt._cached_headed_mode:
+        env_val = os.environ.get("AGENT_BROWSER_HEADED", "").strip()
+        if env_val and env_val.lower() in ("true", "1", "yes"):
+            _bt._cached_headed_mode = True
+
+    return _bt._cached_headed_mode
+
+
+def _should_inject_engine(engine: str) -> bool:
+    """Return True when the engine flag should be added to agent-browser commands.
+
+    Only inject ``--engine`` for non-cloud, non-camofox local sessions where
+    the engine is explicitly set (not ``auto``).
+    """
+    _bt = _origin()
+    if engine == "auto":
+        return False
+    if _bt._is_camofox_mode():
+        return False
+    return _bt._is_local_mode()
+
+
+def _auto_local_for_private_urls() -> bool:
+    """``browser.auto_local_for_private_urls`` (default True), cached for the process.
+
+    When on, ``browser_navigate`` routes private/loopback/LAN URLs to a local
+    Chromium sidecar even with a cloud provider configured; public URLs keep
+    using the cloud provider in the same conversation.
+    """
+    _bt = _origin()
+    if _bt._auto_local_for_private_urls_resolved:
+        return _bt._cached_auto_local_for_private_urls
+
+    _bt._auto_local_for_private_urls_resolved = True
+    _bt._cached_auto_local_for_private_urls = _bt._browser_cfg(
+        "auto_local_for_private_urls", _bt._cached_auto_local_for_private_urls, bool,
+        "auto_local_for_private_urls from config",
+    )
+    return _bt._cached_auto_local_for_private_urls
+
+
+def _use_real_profile() -> bool:
+    """Return whether the user consented to real-profile local browsing.
+
+    Reads ``browser.use_real_profile`` (default False) on EVERY call — it is a
+    consent switch, so flipping it off must take effect without a restart, and
+    in a multiplexed gateway each profile's config must decide for itself.
+    The read is one YAML load per local session creation (not per command),
+    so there is no hot-path cost to keeping it uncached.
+    """
+    _bt = _origin()
+    return _bt._browser_cfg("use_real_profile", False, bool, "use_real_profile from config")
+
+
+def _allow_private_urls() -> bool:
+    """Return whether the browser is allowed to navigate to private/internal addresses.
+
+    Reads ``config["browser"]["allow_private_urls"]``. Single-profile calls
+    cache the result for the process lifetime; multiplexed profile turns resolve
+    their context-local config on each call. Defaults to ``False`` (SSRF
+    protection active).
+    """
+    _bt = _origin()
+
+    # The profile multiplexer scopes config with a ContextVar while sharing
+    # this module. Never reuse another profile's private-network opt-out.
+    if _bt.get_hermes_home_override() is not None:
+        return _bt._resolve_allow_private_urls()
+
+    if _bt._allow_private_urls_resolved:
+        return _bt._cached_allow_private_urls
+
+    _bt._allow_private_urls_resolved = True
+    _bt._cached_allow_private_urls = _bt._resolve_allow_private_urls()
+    return _bt._cached_allow_private_urls
+
+
+def _resolve_allow_private_urls() -> bool:
+    """Read the browser private-URL toggle from the active config scope."""
+    _bt = _origin()
+    return _bt._browser_cfg(
+        "allow_private_urls", False,
+        lambda v: _bt.is_truthy_value(v, default=False),
+        "allow_private_urls from config",
+    )
diff --git a/tools/browser_tool_eval_policy.py b/tools/browser_tool_eval_policy.py
index 143aa99c43..6d8d2aab60 100644
--- a/tools/browser_tool_eval_policy.py
+++ b/tools/browser_tool_eval_policy.py
@@ -65,13 +65,11 @@ def _current_page_private_url(effective_task_id: str) -> Optional[str]:
     _bt = _origin()
     try:
         url_result = _bt._run_browser_command(
-            effective_task_id, "eval", ["window.location.href"],
-            timeout=5, _engine_override="auto",
+            effective_task_id, "eval", ["window.location.href"], timeout=5, _engine_override="auto"
         )
         if url_result.get("success"):
             current_url = (
-                url_result.get("data", {}).get("result", "")
-                .strip().strip('"').strip("'")
+                url_result.get("data", {}).get("result", "") .strip().strip('"').strip("'")
             )
             if current_url and (
                 _bt._is_always_blocked_url(current_url) or not _bt._is_safe_url(current_url)
@@ -96,8 +94,7 @@ _RISKY_BROWSER_EVAL_PATTERNS: tuple[tuple[re.Pattern[str], str], ...] = (
 
 
 _JS_STRING_LITERAL_RE = re.compile(
-    r"""'(?:\\.|[^'\\])*'|\"(?:\\.|[^\"\\])*\"|`(?:\\.|[^`\\])*`""",
-    re.S,
+    r"""'(?:\\.|[^'\\])*'|\"(?:\\.|[^\"\\])*\"|`(?:\\.|[^`\\])*`""", re.S
 )
 
 
diff --git a/tools/browser_tool_install.py b/tools/browser_tool_install.py
new file mode 100644
index 0000000000..9038b5f3b9
--- /dev/null
+++ b/tools/browser_tool_install.py
@@ -0,0 +1,490 @@
+"""agent-browser / Chromium discovery and install: PATH merging, npx resolution, candidate binaries, Chromium detection + auto-install, requirement checks.
+
+Split out of ``tools/browser_tool.py``; every name is re-imported there so
+``tools.browser_tool.<name>`` keeps resolving (and monkeypatching). Origin
+symbols and module state are read/written through ``_bt`` (the origin module,
+resolved per call by :func:`tools.browser_tool_origin.origin_module`) so
+``patch("tools.browser_tool.X")`` is honoured and no import cycle exists.
+"""
+
+import functools
+import os
+import shutil
+import subprocess
+import sys
+from pathlib import Path
+from typing import List, Optional
+
+from tools.browser_tool_origin import origin_module as _origin
+
+
+@functools.lru_cache(maxsize=1)
+def _discover_homebrew_node_dirs() -> tuple[str, ...]:
+    """Find Homebrew versioned Node.js bin directories (e.g. node@20, node@24).
+
+    When Node is installed via ``brew install node@24`` and NOT linked into
+    /opt/homebrew/bin, agent-browser isn't discoverable on the default PATH.
+    This function finds those directories so they can be prepended.
+    """
+    dirs: list[str] = []
+    homebrew_opt = "/opt/homebrew/opt"
+    if not os.path.isdir(homebrew_opt):
+        return tuple(dirs)
+    try:
+        for entry in os.listdir(homebrew_opt):
+            if entry.startswith("node") and entry != "node":
+                bin_dir = os.path.join(homebrew_opt, entry, "bin")
+                if os.path.isdir(bin_dir):
+                    dirs.append(bin_dir)
+    except OSError:
+        pass
+    return tuple(dirs)
+
+
+def _browser_candidate_path_dirs() -> list[str]:
+    """Return ordered browser CLI PATH candidates shared by discovery and execution."""
+    _bt = _origin()
+    hermes_home = _bt.get_hermes_home()
+    hermes_node_bin = str(hermes_home / "node" / "bin")
+    hermes_node_root = str(hermes_home / "node")
+    hermes_nm_bin = str(hermes_home / "node_modules" / ".bin")
+    return [hermes_node_bin, hermes_node_root, hermes_nm_bin, *list(_bt._discover_homebrew_node_dirs()), *_bt._SANE_PATH_DIRS]
+
+
+def _merge_browser_path(existing_path: str = "") -> str:
+    """Prepend browser-specific PATH fallbacks without reordering existing entries."""
+    _bt = _origin()
+    path_parts = [p for p in (existing_path or "").split(os.pathsep) if p]
+    existing_parts = set(path_parts)
+    prefix_parts: list[str] = []
+
+    for part in _bt._browser_candidate_path_dirs():
+        if not part or part in existing_parts or part in prefix_parts:
+            continue
+        if os.path.isdir(part):
+            prefix_parts.append(part)
+
+    return os.pathsep.join(prefix_parts + path_parts)
+
+
+def _browser_install_hint() -> str:
+    _bt = _origin()
+    if _bt._is_termux_environment():
+        return "npm install -g agent-browser && agent-browser install"
+    return "npm install -g agent-browser && agent-browser install --with-deps"
+
+
+def _is_npx_agent_browser_sentinel(browser_cmd: str) -> bool:
+    _bt = _origin()
+    return browser_cmd.strip() == _bt.NPX_AGENT_BROWSER_SENTINEL
+
+
+def _requires_real_termux_browser_install(browser_cmd: str) -> bool:
+    _bt = _origin()
+    return _bt._is_termux_environment() and _bt._is_local_mode() and _bt._is_npx_agent_browser_sentinel(browser_cmd)
+
+
+def _termux_browser_install_error() -> str:
+    _bt = _origin()
+    return (
+        "Local browser automation on Termux cannot rely on the bare npx fallback. "
+        f"Install agent-browser explicitly first: {_bt._browser_install_hint()}"
+    )
+
+
+def _agent_browser_candidate_present(path: str | None) -> bool:
+    if not path:
+        return False
+    if " " in path and path.split()[0].endswith("npx"):
+        return True
+    return os.path.exists(path) and (os.name == "nt" or os.access(path, os.X_OK))
+
+
+def _resolve_npx_bin() -> Optional[str]:
+    """Resolve a runnable npx, preferring the Hermes-managed/Homebrew extended PATH.
+
+    Bare PATH first would let a broken system npx shadow a healthy managed one
+    with no recovery, so every candidate is validated with ``node_tool_runnable``
+    before being trusted.
+    """
+    _bt = _origin()
+    extended_path = _bt._merge_browser_path("")
+    if extended_path:
+        extended_npx = shutil.which("npx", path=extended_path)
+        if extended_npx and _bt.node_tool_runnable(extended_npx):
+            return extended_npx
+    npx_path = shutil.which("npx")
+    if npx_path and _bt.node_tool_runnable(npx_path):
+        return npx_path
+    return None
+
+
+def _agent_browser_candidates(extended_path: str):
+    """Yield agent-browser lookup candidates in resolution order (lazily — each is a filesystem probe).
+
+    Order: ambient PATH (global install) → extended PATH (Hermes-managed Node,
+    macOS versioned Homebrew, Termux/system dirs) → repo-local node_modules/.bin.
+    The local lookup goes through ``shutil.which`` with an explicit path so
+    Windows resolves the ``.cmd`` shim (CreateProcess cannot run npm's
+    extensionless POSIX shim — WinError 193) while POSIX keeps the plain one.
+    """
+    yield shutil.which("agent-browser")
+    if extended_path:
+        yield shutil.which("agent-browser", path=extended_path)
+    local_bin_dir = Path(__file__).parent.parent / "node_modules" / ".bin"
+    if local_bin_dir.is_dir():
+        yield shutil.which("agent-browser", path=str(local_bin_dir))
+
+
+def _find_agent_browser(*, validate: bool = True) -> str:
+    """
+    Find the agent-browser CLI executable.
+
+    Checks in order: current PATH, Homebrew/common bin dirs, Hermes-managed
+    node, local node_modules/.bin/, npx fallback, then a lazy install.
+
+    Every candidate is validated with ``agent_browser_runnable`` before it is
+    cached. A bare ``shutil.which`` hit is NOT trusted: agent-browser's npm
+    postinstall re-points a global symlink at our local node_modules binary,
+    which disappears on the next ``hermes update`` and leaves a dangling link
+    that ``which`` still reports but exec fails on (exit 127). Validating lets a
+    dead candidate fall through instead of being cached and killing every
+    browser tool. ``validate=False`` (schema-time check_fn) only tests presence
+    and never caches.
+
+    Raises:
+        FileNotFoundError: If agent-browser is not installed
+    """
+    _bt = _origin()
+    if _bt._agent_browser_resolved:
+        if _bt._cached_agent_browser is None:
+            raise FileNotFoundError(
+                "agent-browser CLI not found (cached). Install it with: "
+                f"{_bt._browser_install_hint()}\n"
+                "Or ensure npx is available in your PATH."
+            )
+        return _bt._cached_agent_browser
+
+    def _accept(candidate: str) -> str:
+        # _agent_browser_resolved is set at each accept site (not before the
+        # search) so a concurrent reader never sees resolved=True with a None cache.
+        if validate:
+            _bt._cached_agent_browser = candidate
+            _bt._agent_browser_resolved = True
+        return candidate
+
+    ok = _bt.agent_browser_runnable if validate else _bt._agent_browser_candidate_present
+    extended_path = _bt._merge_browser_path("")
+    for candidate in _bt._agent_browser_candidates(extended_path):
+        if candidate and ok(candidate):
+            return _accept(candidate)
+
+    # npx fallback (also searches the extended PATH)
+    if _bt._resolve_npx_bin():
+        return _accept(_bt.NPX_AGENT_BROWSER_SENTINEL)
+
+    if not validate:
+        raise FileNotFoundError("agent-browser CLI not found")
+
+    # Nothing found — try lazy installation before giving up.
+    try:
+        from hermes_cli.dep_ensure import ensure_dependency
+        if ensure_dependency("browser"):
+            candidates = [
+                shutil.which("agent-browser"),
+                shutil.which("agent-browser", path=extended_path) if extended_path else None,
+                shutil.which("agent-browser", path=str(_bt.get_hermes_home() / "node_modules" / ".bin")),
+                shutil.which("agent-browser", path=str(_bt.get_hermes_home() / "node" / "bin")),
+                shutil.which("agent-browser", path=str(_bt.get_hermes_home() / "node")),
+            ]
+            for recheck in candidates:
+                if recheck and _bt.agent_browser_runnable(recheck):
+                    return _accept(recheck)
+    except Exception:
+        pass
+
+    _bt._agent_browser_resolved = True
+    raise FileNotFoundError(
+        "agent-browser CLI not found. Install it with: "
+        f"{_bt._browser_install_hint()}\n"
+        "Or ensure npx is available in your PATH."
+    )
+
+
+def warm_agent_browser_npx_cache(timeout: float = 60.0) -> bool:
+    """Best-effort pre-fetch of the agent-browser npm package via npx.
+
+    agent-browser resolves lazily via ``npx agent-browser`` (not a root
+    package.json dependency), so the first invocation in a session would pay
+    npx's registry fetch; ``hermes update`` / ``hermes doctor --fix`` call this
+    to warm the cache first. Runs with the credential-scrubbed env every other
+    agent-browser spawn uses (registry-fetched npm code must never see the
+    operator keyring), in its own process group, and tree-kills on timeout so
+    a surviving descendant cannot hold the capture pipe open.
+    Never raises; True only when npx actually exited 0.
+    """
+    _bt = _origin()
+    npx_bin = _bt._resolve_npx_bin()
+    if not npx_bin:
+        return False
+
+    env = _bt._build_browser_env()
+    env["PATH"] = _bt._merge_browser_path(env.get("PATH", ""))
+
+    popen_kwargs: dict = {
+        "stdout": subprocess.PIPE,
+        "stderr": subprocess.PIPE,
+        "text": True,
+        "env": env,
+        "creationflags": _bt.windows_hide_flags(),
+    }
+    if os.name == "posix":
+        popen_kwargs["start_new_session"] = True
+    else:
+        popen_kwargs["creationflags"] |= getattr(subprocess, "CREATE_NEW_PROCESS_GROUP", 0)
+
+    cmd = [
+        npx_bin,
+        # --ignore-scripts: AGENT_BROWSER_NPX_SPEC is a floating ^0.26.0
+        # range, not an exact pin — a compromised future 0.26.x patch must
+        # not get to run its own install-time lifecycle scripts here.
+        "--ignore-scripts",
+        # --prefer-offline: once cached, repeat `hermes update`/`doctor
+        # --fix` runs shouldn't hit the registry just to re-confirm
+        # "latest" is still latest — that would defeat the point of
+        # warming the cache in the first place.
+        "--prefer-offline",
+        "-y",
+        _bt.AGENT_BROWSER_NPX_SPEC,
+        "--version",
+    ]
+    try:
+        proc = subprocess.Popen(cmd, stdin=subprocess.DEVNULL, **popen_kwargs)
+    except Exception:
+        return False
+    try:
+        proc.communicate(timeout=timeout)
+        return proc.returncode == 0
+    except subprocess.TimeoutExpired:
+        _bt._kill_process_tree(proc)
+        try:
+            proc.communicate(timeout=5)
+        except Exception:
+            pass
+        return False
+    except Exception:
+        _bt._kill_process_tree(proc)
+        return False
+
+
+def _chromium_search_roots() -> List[str]:
+    """Directories to scan for a Chromium / headless-shell build, in the order
+    agent-browser and Playwright probe them: ``PLAYWRIGHT_BROWSERS_PATH``, then
+    Playwright's per-OS default cache."""
+    roots: List[str] = []
+    env_path = os.environ.get("PLAYWRIGHT_BROWSERS_PATH", "").strip()
+    if env_path and env_path != "0":
+        roots.append(env_path)
+    home = os.path.expanduser("~")
+    roots.append(os.path.join(home, ".cache", "ms-playwright"))
+    if sys.platform == "darwin":
+        roots.append(os.path.join(home, "Library", "Caches", "ms-playwright"))
+    if sys.platform == "win32":
+        local = os.environ.get("LOCALAPPDATA") or os.path.join(
+            home, "AppData", "Local"
+        )
+        roots.append(os.path.join(local, "ms-playwright"))
+    return roots
+
+
+def _chromium_installed() -> bool:
+    """Return True when a usable Chromium (or headless-shell) build is on disk.
+
+    Checks ``AGENT_BROWSER_EXECUTABLE_PATH``, then system Chrome/Chromium on
+    PATH, then Playwright's cache (``chromium-*`` / ``chromium_headless_shell-*``
+    dirs). Without a binary the CLI hangs on first use until the command
+    timeout fires, so the tool must not be advertised.
+    """
+    _bt = _origin()
+    if _bt._cached_chromium_installed is not None:
+        return _bt._cached_chromium_installed
+
+    # 1. AGENT_BROWSER_EXECUTABLE_PATH — explicit user-configured browser
+    ab_path = os.environ.get("AGENT_BROWSER_EXECUTABLE_PATH", "").strip()
+    if ab_path and (os.path.isfile(ab_path) or shutil.which(ab_path)):
+        _bt._cached_chromium_installed = True
+        return True
+
+    # 2. System Chrome/Chromium in PATH (common names)
+    system_chrome = (
+        shutil.which("google-chrome")
+        or shutil.which("chromium")
+        or shutil.which("chromium-browser")
+        or shutil.which("chrome")
+    )
+    if system_chrome:
+        _bt._cached_chromium_installed = True
+        return True
+
+    # 3. Playwright browser cache (legacy — chromium-* / chromium_headless_shell-* dirs)
+    for root in _bt._chromium_search_roots():
+        if not root or not os.path.isdir(root):
+            continue
+        try:
+            entries = os.listdir(root)
+        except OSError:
+            continue
+        # Playwright names them ``chromium-<build>`` and
+        # ``chromium_headless_shell-<build>``; agent-browser accepts either.
+        for entry in entries:
+            if entry.startswith("chromium-") or entry.startswith(
+                "chromium_headless_shell-"
+            ):
+                _bt._cached_chromium_installed = True
+                return True
+
+    _bt._cached_chromium_installed = False
+    return False
+
+
+def _maybe_autoinstall_chromium() -> bool:
+    """Best-effort, gated download of the Chromium *binary* on local cold start.
+
+    Binary only (``agent-browser install``), never ``--with-deps`` — that shells
+    ``apt`` and needs root, so missing system libraries stay a user action.
+    Gated by ``security.allow_lazy_installs``, skipped in Docker (Chromium ships
+    in the image), attempted once per process. True only when Chromium is
+    present afterwards.
+    """
+    _bt = _origin()
+    if _bt._chromium_autoinstall_attempted:
+        return _bt._chromium_installed()
+    _bt._chromium_autoinstall_attempted = True
+
+    if _bt._running_in_docker():
+        return False
+
+    from tools.lazy_deps import _allow_lazy_installs
+    if not _allow_lazy_installs():
+        return False
+
+    try:
+        browser_cmd = _bt._find_agent_browser()
+    except FileNotFoundError:
+        return False
+
+    if _bt._is_npx_agent_browser_sentinel(browser_cmd):
+        install_cmd = [
+            _bt._resolve_npx_bin() or "npx", "--ignore-scripts", "-y", _bt.AGENT_BROWSER_NPX_SPEC, "install",
+        ]
+    else:
+        install_cmd = [browser_cmd, "install"]
+
+    _bt.logger.info(
+        "browser: Chromium missing — auto-installing the browser binary "
+        "(one-time ~170MB; disable via security.allow_lazy_installs)"
+    )
+    try:
+        proc = subprocess.run(
+            install_cmd,
+            capture_output=True,
+            text=True, encoding='utf-8', errors='replace',
+            timeout=600,
+            env=_bt._build_browser_env(),
+        )
+    except (OSError, subprocess.SubprocessError) as e:
+        _bt.logger.warning("browser: Chromium auto-install failed to start: %s", e)
+        return False
+
+    if proc.returncode != 0:
+        tail = (proc.stderr or proc.stdout or "").strip()[-300:]
+        _bt.logger.warning(
+            "browser: Chromium auto-install exited %s: %s", proc.returncode, tail
+        )
+        return False
+
+    _bt._cached_chromium_installed = None
+    return _bt._chromium_installed()
+
+
+def _running_in_docker() -> bool:
+    """Best-effort detection of whether we're inside a Docker container."""
+    if os.path.exists("/.dockerenv"):
+        return True
+    try:
+        with open("/proc/1/cgroup", "rt", encoding="utf-8") as fp:
+            return "docker" in fp.read()
+    except OSError:
+        return False
+
+
+def check_browser_requirements() -> bool:
+    """Whether the browser tools should be advertised.
+
+    Local mode needs the ``agent-browser`` CLI plus a Chromium build (except
+    Lightpanda-only text workflows); cloud mode needs the CLI plus provider
+    credentials (the provider hosts its own Chromium).
+    """
+    # Browser Use CLI backend — browser_exec replaces the whole browser_*
+    # surface (including browser_cdp/browser_dialog, whose check_fns funnel
+    # through here), so hide these tools from the model.
+    _bt = _origin()
+    if _bt._is_browser_use_cli_mode():
+        return False
+
+    # Camofox backend — only needs the server URL, no agent-browser CLI
+    if _bt._is_camofox_mode():
+        return True
+
+    # CDP override mode can connect to an existing remote/local browser endpoint
+    # without requiring the local agent-browser binary on PATH.
+    # Raw (no-I/O) check: this runs during tool-schema assembly at startup,
+    # where a stale endpoint must not cost a blocking HTTP probe.
+    if _bt._get_cdp_override_raw():
+        return True
+
+    # The agent-browser CLI is required for local launch and cloud-provider flows.
+    # Tool-schema assembly runs during Desktop startup; do not execute
+    # ``agent-browser --version`` here, because Windows .cmd shims route through
+    # cmd.exe and can flash a console before the user invokes any browser tool.
+    # Actual browser execution paths still validate the candidate before use.
+    try:
+        browser_cmd = _bt._find_agent_browser(validate=False)
+    except FileNotFoundError:
+        return False
+
+    # On Termux, the bare npx fallback is too fragile to treat as a satisfied
+    # local browser dependency. Require a real install (global or local) so the
+    # browser tool is not advertised as available when it will likely fail on
+    # first use.
+    if _bt._requires_real_termux_browser_install(browser_cmd):
+        return False
+
+    # In cloud mode, also require provider credentials. Cloud browsers
+    # don't need a local Chromium binary.
+    provider = _bt._get_cloud_provider()
+    if provider is not None:
+        return provider.is_configured()
+
+    # Local mode with Lightpanda can provide text/navigation tools without a
+    # local Chromium install. Chrome fallback, screenshots, and browser_vision
+    # will still return actionable Chromium install errors if invoked.
+    if _bt._using_lightpanda_engine():
+        return True
+
+    # Local Chrome mode: agent-browser needs a Chromium build on disk. Without
+    # it the CLI hangs on first use until the command timeout fires.
+    return _bt._chromium_installed()
+
+
+def check_browser_vision_requirements() -> bool:
+    """Advertise ``browser_vision`` only with BOTH a working browser AND a vision
+    backend — otherwise it fails at call time with a cryptic provider error."""
+    _bt = _origin()
+    if not _bt.check_browser_requirements():
+        return False
+    try:
+        from tools.vision_tools import check_vision_requirements
+    except ImportError:
+        return False
+    return check_vision_requirements()
diff --git a/tools/browser_tool_lifecycle.py b/tools/browser_tool_lifecycle.py
new file mode 100644
index 0000000000..97a94472fd
--- /dev/null
+++ b/tools/browser_tool_lifecycle.py
@@ -0,0 +1,864 @@
+"""Browser session lifecycle: inactivity janitor, orphan reaper, per-session teardown, atexit emergency cleanup.
+
+Split out of ``tools/browser_tool.py``; every name is re-imported there so
+``tools.browser_tool.<name>`` keeps resolving (and monkeypatching). Origin
+symbols and module state are read/written through ``_bt`` (the origin module,
+resolved per call by :func:`tools.browser_tool_origin.origin_module`) so
+``patch("tools.browser_tool.X")`` is honoured and no import cycle exists.
+"""
+
+import contextlib
+import os
+import shutil
+import signal
+import subprocess
+import threading
+import time
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any, Dict, Optional, Tuple
+
+from hermes_constants import get_hermes_home, reset_hermes_home_override, set_hermes_home_override
+from tools.browser_tool_origin import origin_module as _origin
+
+
+def _session_expiry_timestamp(session_info: Dict[str, Any]) -> Optional[float]:
+    """Return a provider-authoritative session expiry as epoch seconds.
+
+    Cloud providers may omit ``expires_at``. Unknown or malformed values are
+    therefore treated as having no known expiry, preserving the existing
+    lifecycle for local browsers and providers without an expiry contract.
+    """
+    _bt = _origin()
+    value = session_info.get("expires_at")
+    if isinstance(value, (int, float)) and not isinstance(value, bool):
+        return float(value)
+    if not isinstance(value, str) or not value.strip():
+        return None
+
+    normalized = value.strip()
+    if normalized.endswith(("Z", "z")):
+        normalized = f"{normalized[:-1]}+00:00"
+    try:
+        parsed = datetime.fromisoformat(normalized)
+    except ValueError:
+        _bt.logger.warning("Ignoring invalid cloud browser session expiry timestamp")
+        return None
+    if parsed.tzinfo is None:
+        parsed = parsed.replace(tzinfo=timezone.utc)
+    return parsed.timestamp()
+
+
+def _session_has_expired(
+    session_info: Dict[str, Any], *, now: Optional[float] = None
+) -> bool:
+    """Return whether a cached browser session crossed its provider deadline."""
+    _bt = _origin()
+    expires_at = _bt._session_expiry_timestamp(session_info)
+    if expires_at is None:
+        return False
+    return (time.time() if now is None else now) >= expires_at
+
+
+def _emergency_cleanup_all_sessions():
+    """
+    Emergency cleanup of all active browser sessions.
+    Called on process exit or interrupt to prevent orphaned sessions.
+
+    Also runs the orphan reaper to clean up daemons left behind by previously
+    crashed hermes processes — this way every clean hermes exit sweeps
+    accumulated orphans, not just ones that actively used the browser tool.
+    """
+    _bt = _origin()
+    if _bt._cleanup_done:
+        return
+    _bt._cleanup_done = True
+
+    # Clean up this process's own sessions first, so their owner_pid files
+    # are removed before the reaper scans.
+    # Real-profile Chrome processes are launched directly (not by
+    # agent-browser), so the session cleanup below never reaps them.
+    try:
+        _bt._terminate_real_profile_chrome()
+    except Exception as e:
+        _bt.logger.debug("Real-profile chrome cleanup on exit failed: %s", e)
+    if _bt._active_sessions:
+        _bt.logger.info("Emergency cleanup: closing %s active session(s)...",
+                    len(_bt._active_sessions))
+        try:
+            _bt.cleanup_all_browsers()
+        except Exception as e:
+            _bt.logger.error("Emergency cleanup error: %s", e)
+        finally:
+            with _bt._cleanup_lock:
+                _bt._active_sessions.clear()
+                _bt._session_last_activity.clear()
+                _bt._session_owner_homes.clear()
+                _bt._cleanup_failures.clear()
+                _bt._recording_sessions.clear()
+
+    # Lightpanda servers (Browser Use mode) are processes we spawned; the
+    # session cleanup above stops the tracked ones, this catches any that
+    # fell out of ``_active_sessions``.
+    try:
+        from tools.browser_lightpanda import stop_all_lightpanda
+
+        stop_all_lightpanda()
+    except Exception as e:
+        _bt.logger.debug("Lightpanda cleanup on exit failed: %s", e)
+
+    # Sweep orphans from other crashed hermes processes.  Safe even if we
+    # never used the browser — uses owner_pid liveness to avoid reaping
+    # daemons owned by other live hermes processes.
+    try:
+        _bt._reap_orphaned_browser_sessions()
+    except Exception as e:
+        _bt.logger.debug("Orphan reap on exit failed: %s", e)
+
+
+@contextlib.contextmanager
+def _session_owner_scope(task_id: str):
+    """Run under the Hermes home + secret scope owning ``task_id``'s session (no-op if unrecorded).
+
+    The janitor thread is process-global, so each teardown must re-enter its
+    OWN profile's scope rather than inherit the spawning profile's; never falls
+    through to ``os.environ``.
+    """
+    _bt = _origin()
+    owner_home = _bt._session_owner_homes.get(task_id)
+    if owner_home is None:
+        yield
+        return
+
+    from agent.secret_scope import (
+        build_profile_secret_scope, reset_secret_scope, set_secret_scope
+    )
+    from hermes_cli.env_loader import hydrate_profile_secret_sources
+
+    home_token = set_hermes_home_override(owner_home)
+    try:
+        hydrate_profile_secret_sources(Path(owner_home))
+        secret_token = set_secret_scope(build_profile_secret_scope(Path(owner_home)))
+        try:
+            yield
+        finally:
+            reset_secret_scope(secret_token)
+    finally:
+        reset_hermes_home_override(home_token)
+
+
+def _cleanup_inactive_browser_sessions():
+    """Close sessions inactive longer than the timeout (called by the cleanup thread).
+
+    Each session is torn down under its owner profile's scope. A session whose
+    cleanup keeps failing is force-reaped after MAX_INACTIVITY_CLEANUP_FAILURES
+    attempts instead of retrying forever; only a successful cleanup clears its
+    failure count.
+    """
+    _bt = _origin()
+    current_time = time.time()
+    sessions_to_cleanup = []
+
+    with _bt._cleanup_lock:
+        for task_id, last_time in list(_bt._session_last_activity.items()):
+            if current_time - last_time > _bt.BROWSER_SESSION_INACTIVITY_TIMEOUT:
+                sessions_to_cleanup.append(task_id)
+
+    for task_id in sessions_to_cleanup:
+        elapsed = int(current_time - _bt._session_last_activity.get(task_id, current_time))
+        _bt.logger.info("Cleaning up inactive session for task: %s (inactive for %ss)", task_id, elapsed)
+        try:
+            with _bt._session_owner_scope(task_id):
+                _bt.cleanup_browser(task_id)
+            with _bt._cleanup_lock:
+                _bt._session_last_activity.pop(task_id, None)
+                _bt._session_owner_homes.pop(task_id, None)
+                _bt._cleanup_failures.pop(task_id, None)
+        except Exception as e:
+            with _bt._cleanup_lock:
+                failures = _bt._cleanup_failures[task_id] = _bt._cleanup_failures.get(task_id, 0) + 1
+            if failures < _bt.MAX_INACTIVITY_CLEANUP_FAILURES:
+                _bt.logger.warning("Error cleaning up inactive session %s (attempt %d/%d): %s",
+                               task_id, failures, _bt.MAX_INACTIVITY_CLEANUP_FAILURES, e)
+                continue
+            _bt.logger.error("Browser cleanup failed %d times for inactive session %s; "
+                         "force-reaping: %s", failures, task_id, e)
+            try:
+                with _bt._session_owner_scope(task_id):
+                    _bt._force_reap_browser_session(task_id)
+            except Exception as reap_exc:
+                _bt.logger.error("Force-reap of browser session %s failed: %s", task_id, reap_exc)
+            finally:
+                with _bt._cleanup_lock:
+                    _bt._session_owner_homes.pop(task_id, None)
+                    _bt._cleanup_failures.pop(task_id, None)
+
+
+def _write_owner_pid(socket_dir: str, session_name: str) -> None:
+    """Record the current hermes PID as the owner of a browser socket dir.
+
+    Written atomically to ``<socket_dir>/<session_name>.owner_pid`` so the
+    orphan reaper can distinguish daemons owned by a live hermes process
+    (don't reap) from daemons whose owner crashed (reap).  Best-effort —
+    an OSError here just falls back to the legacy ``tracked_names``
+    heuristic in the reaper.
+    """
+    _bt = _origin()
+    try:
+        path = os.path.join(socket_dir, f"{session_name}.owner_pid")
+        with open(path, "w", encoding="utf-8") as f:
+            f.write(str(os.getpid()))
+    except OSError as exc:
+        _bt.logger.debug("Could not write owner_pid file for %s: %s",
+                     session_name, exc)
+
+
+def _verify_reapable_browser_daemon(daemon_pid: int, socket_dir: str,
+                                    session_name: str) -> bool:
+    """Confirm a live PID is genuinely *this* session's agent-browser daemon.
+
+    The ``.pid`` file lives in a world-writable, predictably-named temp dir and
+    is written by the daemon, not us: a same-user actor can plant one pointing
+    at a victim PID, or a recycled PID can land on an unrelated process — and
+    reaping is a *tree* kill, i.e. an arbitrary-process DoS. Two psutil checks
+    must both pass: (1) identity — ``agent-browser`` in the name or cmdline;
+    (2) binding — the socket dir path/basename in the cmdline, or
+    ``AGENT_BROWSER_SOCKET_DIR`` in its environ. (2) is the real spoof defense:
+    an attacker would need a real daemon embedding this exact path, which they
+    could already signal. Fail-closed on any ambiguity (unreadable cmdline, no
+    match): refuse to reap and leave process and socket dir alone.
+    """
+    _bt = _origin()
+    try:
+        import psutil
+    except ImportError:  # psutil is a hard dep; defensive only
+        _bt.logger.warning(
+            "Refusing to reap browser daemon PID %d (session %s): "
+            "psutil unavailable for identity verification",
+            daemon_pid, session_name)
+        return False
+
+    try:
+        proc = psutil.Process(daemon_pid)
+        name = (proc.name() or "").lower()
+        cmdline = " ".join(proc.cmdline() or []).lower()
+    except psutil.NoSuchProcess:
+        # Vanished between the liveness check and now — nothing to reap.
+        return False
+    except (psutil.AccessDenied, OSError) as exc:
+        _bt.logger.warning(
+            "Refusing to reap browser daemon PID %d (session %s): "
+            "could not read process identity (%s)",
+            daemon_pid, session_name, exc)
+        return False
+
+    looks_like_browser = "agent-browser" in name or "agent-browser" in cmdline
+    if not looks_like_browser:
+        _bt.logger.warning(
+            "Refusing to reap PID %d (session %s): not an agent-browser "
+            "process (name=%r)", daemon_pid, session_name, name)
+        return False
+
+    # Binding check: the live process must reference *this* socket dir.
+    socket_dir_l = socket_dir.lower()
+    socket_base_l = os.path.basename(socket_dir).lower()
+    bound = socket_dir_l in cmdline or (
+        socket_base_l and socket_base_l in cmdline)
+    if not bound:
+        try:
+            env_dir = (proc.environ() or {}).get(
+                "AGENT_BROWSER_SOCKET_DIR", "")
+            bound = bool(env_dir) and os.path.normpath(env_dir) == \
+                os.path.normpath(socket_dir)
+        except (psutil.AccessDenied, psutil.NoSuchProcess, OSError):
+            # environ() can be denied even same-user on some platforms.
+            # cmdline already failed to bind — fail closed.
+            bound = False
+
+    if not bound:
+        _bt.logger.warning(
+            "Refusing to reap agent-browser PID %d: not bound to session "
+            "socket dir %s (possible recycled PID or planted pid file)",
+            daemon_pid, socket_dir)
+        return False
+
+    return True
+
+
+def _socket_dir_idle_seconds(socket_dir: str) -> Optional[float]:
+    """Seconds since anything in ``socket_dir`` was last written; None if unknown (fail safe).
+
+    Every command writes ``_stdout_<cmd>`` / ``_stderr_<cmd>`` there, so the
+    newest mtime is a last-activity marker that survives hermes restarts and
+    lost in-memory bookkeeping. The dir's own mtime is not enough — rewriting
+    an existing ``_stdout_click`` doesn't touch it — so entries are scanned too.
+    """
+    try:
+        latest = os.path.getmtime(socket_dir)
+    except OSError:
+        return None
+
+    try:
+        with os.scandir(socket_dir) as entries:
+            for entry in entries:
+                try:
+                    latest = max(latest, entry.stat().st_mtime)
+                except OSError:
+                    continue
+    except OSError:
+        pass  # dir mtime alone is still a usable lower bound
+
+    return max(0.0, time.time() - latest)
+
+
+def _owner_pid_alive(socket_dir: str, session_name: str) -> Tuple[Optional[int], Optional[bool]]:
+    """Read ``<session>.owner_pid`` and report ``(pid, alive)``; ``(None, None)`` when missing/corrupt."""
+    owner_pid_file = os.path.join(socket_dir, f"{session_name}.owner_pid")
+    if not os.path.isfile(owner_pid_file):
+        return None, None
+    try:
+        owner_pid = int(Path(owner_pid_file).read_text(encoding="utf-8").strip())
+        # ``os.kill(pid, 0)`` is NOT a no-op on Windows; use the cross-platform check.
+        from gateway.status import _pid_exists
+        return owner_pid, _pid_exists(owner_pid)
+    except (ValueError, OSError):
+        return None, None  # corrupt file — fall through to legacy handling
+
+
+def _reap_socket_dir(socket_dir: str, session_name: str, tracked_names: set) -> bool:
+    """Reap one ``agent-browser-<session>`` dir if orphaned; return True when a daemon was killed.
+
+    Ownership priority: (1) a live ``owner_pid`` means another hermes process
+    owns it — leave it alone UNLESS it is untracked here and idle past
+    ``BROWSER_ORPHAN_GRACE_SECONDS`` (owner-alive alone made leaked daemons
+    immortal: in-memory tracking is lost on any exception path and the daemon's
+    own idle timeout doesn't fire when it is wedged); (2) no owner_pid (legacy)
+    falls back to this process's tracking. A pidless dir is only stale after the
+    grace period — deleting it immediately races the creator's first stdout open.
+    The daemon PID is verified as ours before a tree-kill (world-writable dir,
+    recycled PIDs), and refused without a start-time fingerprint.
+    """
+    _bt = _origin()
+    owner_pid, owner_alive = _bt._owner_pid_alive(socket_dir, session_name)
+    if owner_alive is True:
+        if session_name in tracked_names:
+            return False
+        idle_s = _bt._socket_dir_idle_seconds(socket_dir)
+        if idle_s is None or idle_s < _bt.BROWSER_ORPHAN_GRACE_SECONDS:
+            return False  # unknown age or within grace — fail safe
+        _bt.logger.warning(
+            "Browser session %s has a live owner (PID %s) but is untracked "
+            "and idle for %ds (grace %ds) — treating as leaked and reaping",
+            session_name, owner_pid, int(idle_s),
+            _bt.BROWSER_ORPHAN_GRACE_SECONDS)
+    elif owner_alive is None and session_name in tracked_names:
+        return False
+
+    pid_file = os.path.join(socket_dir, f"{session_name}.pid")
+    if not os.path.isfile(pid_file):
+        idle_s = _bt._socket_dir_idle_seconds(socket_dir)
+        if idle_s is None or idle_s < _bt.BROWSER_ORPHAN_GRACE_SECONDS:
+            return False
+        shutil.rmtree(socket_dir, ignore_errors=True)
+        return False
+
+    try:
+        daemon_pid = int(Path(pid_file).read_text(encoding="utf-8").strip())
+    except (ValueError, OSError):
+        shutil.rmtree(socket_dir, ignore_errors=True)
+        return False
+
+    from gateway.status import _pid_exists
+    if not _pid_exists(daemon_pid):
+        shutil.rmtree(socket_dir, ignore_errors=True)
+        return False
+
+    if not _bt._verify_reapable_browser_daemon(daemon_pid, socket_dir, session_name):
+        return False  # leave process and dir for a later sweep once the imposter PID is gone
+
+    # Tree-kill so Chromium children (renderer, GPU, ...) go too, not just the daemon.
+    reaped = False
+    try:
+        from gateway.status import get_process_start_time
+        from tools.process_registry import ProcessRegistry
+        daemon_start = get_process_start_time(daemon_pid)
+        if daemon_start is None:
+            _bt.logger.warning(
+                "Refusing to reap browser daemon PID %d (session %s): "
+                "no start-time fingerprint available", daemon_pid, session_name)
+            return False
+        ProcessRegistry._terminate_host_pid(daemon_pid, daemon_start)
+        _bt.logger.info("Reaped orphaned browser daemon PID %d (session %s)",
+                    daemon_pid, session_name)
+        reaped = True
+    except (ProcessLookupError, PermissionError, OSError):
+        pass
+    shutil.rmtree(socket_dir, ignore_errors=True)
+    return reaped
+
+
+def _reap_orphaned_browser_sessions():
+    """Kill agent-browser daemons whose owning hermes process is gone.
+
+    When the process that created a session exits uncleanly (SIGKILL, crash,
+    gateway restart) the in-memory ``_active_sessions`` tracking is lost but the
+    node + Chromium processes keep running. Scans the tmp dir for
+    ``agent-browser-*`` socket dirs and applies ``_reap_socket_dir``'s ownership
+    rules (owner_pid file first — cross-process safe, two hermes instances never
+    reap each other — then in-process tracking for legacy daemons).
+    Safe to call from any context — atexit, cleanup thread, or on demand.
+    """
+    _bt = _origin()
+    import glob
+
+    # Lightpanda servers (Browser Use mode) keep their own records (no
+    # agent-browser socket dir); sweep them with the same owner-liveness rule
+    # BEFORE the daemon scan, which may return early.
+    try:
+        from tools.browser_lightpanda import reap_orphaned_lightpanda
+
+        reap_orphaned_lightpanda()
+    except Exception as e:
+        _bt.logger.debug("Lightpanda orphan reap failed: %s", e)
+
+    tmpdir = _bt._socket_safe_tmpdir()
+    socket_dirs = []
+    for prefix in ("agent-browser-h_*", "agent-browser-cdp_*", "agent-browser-hermes_*"):
+        socket_dirs += glob.glob(os.path.join(tmpdir, prefix))
+    if not socket_dirs:
+        return
+
+    with _bt._cleanup_lock:
+        tracked_names = {
+            info.get("session_name")
+            for info in _bt._active_sessions.values()
+            if info.get("session_name")
+        }
+
+    reaped = 0
+    for socket_dir in socket_dirs:
+        session_name = os.path.basename(socket_dir).removeprefix("agent-browser-")
+        if session_name and _bt._reap_socket_dir(socket_dir, session_name, tracked_names):
+            reaped += 1
+
+    if reaped:
+        _bt.logger.info("Reaped %d orphaned browser session(s) from previous run(s)", reaped)
+
+
+def _browser_cleanup_thread_worker():
+    """Every 30s: close sessions idle past BROWSER_SESSION_INACTIVITY_TIMEOUT.
+
+    Also reaps orphaned daemons on startup AND every BROWSER_ORPHAN_REAP_INTERVAL
+    seconds — a daemon can fall out of in-memory tracking at any point in a
+    long-lived process, and a startup-only reap could never recover from that.
+    """
+    _bt = _origin()
+    reap_every_cycles = max(1, round(_bt.BROWSER_ORPHAN_REAP_INTERVAL / 30))
+    cycle = 0
+
+    while _bt._cleanup_running:
+        # cycle 0 is the startup reap; then every reap_every_cycles.
+        if cycle % reap_every_cycles == 0:
+            try:
+                _bt._reap_orphaned_browser_sessions()
+            except Exception as e:
+                _bt.logger.warning("Orphan reap error: %s", e)
+        cycle += 1
+
+        try:
+            _bt._cleanup_inactive_browser_sessions()
+        except Exception as e:
+            _bt.logger.warning("Cleanup thread error: %s", e)
+
+        # Sleep in 1-second intervals so we can stop quickly if needed
+        for _ in range(30):
+            if not _bt._cleanup_running:
+                break
+            time.sleep(1)
+
+
+def _start_browser_cleanup_thread():
+    """Start the background cleanup thread if not already running."""
+    _bt = _origin()
+
+    with _bt._cleanup_lock:
+        if _bt._cleanup_thread is None or not _bt._cleanup_thread.is_alive():
+            _bt._cleanup_running = True
+            _bt._cleanup_thread = threading.Thread(
+                target=_bt._browser_cleanup_thread_worker, daemon=True, name="browser-cleanup"
+            )
+            _bt._cleanup_thread.start()
+            _bt.logger.info("Started inactivity cleanup thread (timeout: %ss)", _bt.BROWSER_SESSION_INACTIVITY_TIMEOUT)
+
+
+def _stop_browser_cleanup_thread():
+    """Stop the background cleanup thread."""
+    _bt = _origin()
+    _bt._cleanup_running = False
+    if _bt._cleanup_thread is not None:
+        _bt._cleanup_thread.join(timeout=5)
+
+
+def _update_session_activity(task_id: str):
+    """Update the last activity timestamp for a session.
+
+    Also records the owning Hermes home on first sight so the process-global
+    janitor can tear the session down under its owner's scope.  An
+    activity touch deliberately does NOT reset ``_cleanup_failures`` — only a
+    successful cleanup does.
+    """
+    _bt = _origin()
+    with _bt._cleanup_lock:
+        _bt._session_last_activity[task_id] = time.time()
+        _bt._session_owner_homes.setdefault(task_id, str(get_hermes_home()))
+
+
+def _kill_process_tree(proc: "subprocess.Popen") -> None:
+    """Best-effort kill of *proc* and every descendant it spawned; never raises.
+
+    ``Popen.kill()`` only signals the direct child. npm/npx fork helpers and
+    agent-browser's detached daemon grandchild, which survive a plain kill and
+    keep a capture pipe open so ``communicate()`` never sees EOF — on Windows
+    there is no non-blocking read to poll around that, so the whole tree must
+    go. No grace period: the caller already burned its full timeout waiting.
+    Delegates to :func:`agent.deadline.kill_process_tree` (taskkill /T /F,
+    killpg, plus a psutil sweep that reaches ``setsid``'d descendants) and
+    falls back to :func:`_legacy_kill_process_tree` on any failure.
+    """
+    _bt = _origin()
+    try:
+        from agent.deadline import kill_process_tree as _deadline_kill_tree
+
+        _deadline_kill_tree(proc.pid)
+    except Exception:
+        _bt._legacy_kill_process_tree(proc)
+
+
+def _legacy_kill_process_tree(proc: "subprocess.Popen") -> None:
+    """Local tree-kill — fallback when agent.deadline is unavailable."""
+    if os.name == "nt":
+        try:
+            subprocess.run(
+                ["taskkill", "/PID", str(proc.pid), "/T", "/F"],
+                check=False,
+                capture_output=True,
+                stdin=subprocess.DEVNULL,
+            )
+        except Exception:
+            pass
+        return
+    # os.killpg/signal.SIGKILL don't exist on Windows; this branch is
+    # POSIX-only (the `os.name == "nt"` check above already returns first
+    # on Windows), but resolve them defensively via getattr anyway so an
+    # accidental future refactor that drops that guard degrades to a plain
+    # kill() instead of AttributeError — same discipline as
+    # tools/mcp_stdio_watchdog.py's _terminate_process_group.
+    killpg = getattr(os, "killpg", None)
+    if killpg is None:  # windows-footgun: ok - non-POSIX fallback
+        try:
+            proc.kill()
+        except Exception:
+            pass
+        return
+    try:
+        pgid = os.getpgid(proc.pid)
+    except (ProcessLookupError, OSError):
+        return
+    sigkill = getattr(signal, "SIGKILL", signal.SIGTERM)
+    for sig in (signal.SIGTERM, sigkill):
+        try:
+            killpg(pgid, sig)
+        except (ProcessLookupError, PermissionError, OSError):
+            return
+
+
+def _pid_exists(pid: int) -> bool:
+    """Best-effort 'is this PID alive' check (signal 0 / psutil on Windows)."""
+    if pid <= 0:
+        return False
+    if os.name == "nt":
+        try:
+            import psutil
+
+            return psutil.pid_exists(pid)
+        except Exception:
+            return False
+    try:
+        os.kill(pid, 0)  # windows-footgun: ok — psutil.pid_exists above handles Windows
+    except ProcessLookupError:
+        return False
+    except PermissionError:
+        return True
+    except OSError:
+        return False
+    return True
+
+
+def _cleanup_old_screenshots(screenshots_dir, max_age_hours=24):
+    """Remove browser screenshots older than max_age_hours to prevent disk bloat.
+
+    Throttled to run at most once per hour per directory to avoid repeated
+    scans on screenshot-heavy workflows.
+    """
+    _bt = _origin()
+    key = str(screenshots_dir)
+    now = time.time()
+    if now - _bt._last_screenshot_cleanup_by_dir.get(key, 0.0) < 3600:
+        return
+    _bt._last_screenshot_cleanup_by_dir[key] = now
+
+    try:
+        cutoff = time.time() - (max_age_hours * 3600)
+        for f in screenshots_dir.glob("browser_screenshot_*.png"):
+            try:
+                if f.stat().st_mtime < cutoff:
+                    f.unlink()
+            except Exception as e:
+                _bt.logger.debug("Failed to clean old screenshot %s: %s", f, e)
+    except Exception as e:
+        _bt.logger.debug("Screenshot cleanup error (non-critical): %s", e)
+
+
+def _cleanup_old_recordings(max_age_hours=72):
+    """Remove browser recordings older than max_age_hours to prevent disk bloat."""
+    _bt = _origin()
+    try:
+        hermes_home = get_hermes_home()
+        recordings_dir = hermes_home / "browser_recordings"
+        if not recordings_dir.exists():
+            return
+        cutoff = time.time() - (max_age_hours * 3600)
+        for f in recordings_dir.glob("session_*.webm"):
+            try:
+                if f.stat().st_mtime < cutoff:
+                    f.unlink()
+            except Exception as e:
+                _bt.logger.debug("Failed to clean old recording %s: %s", f, e)
+    except Exception as e:
+        _bt.logger.debug("Recording cleanup error (non-critical): %s", e)
+
+
+def _drop_last_active_binding(task_id: str) -> None:
+    """Drop stale last-active ownership after cleaning ``task_id``.
+
+    Cleaning a bare task drops its binding; cleaning a sidecar drops the binding
+    only if that sidecar was still the recorded owner — so a later
+    click/snapshot can't resurrect a cleaned sidecar on about:blank while a
+    primary-session binding is preserved.
+    """
+    _bt = _origin()
+    if _bt._is_local_sidecar_key(task_id):
+        bare_task_id = _bt._bare_task_id_for_session_key(task_id)
+        if _bt._last_active_session_key.get(bare_task_id) == task_id:
+            _bt._last_active_session_key.pop(bare_task_id, None)
+    else:
+        _bt._last_active_session_key.pop(task_id, None)
+
+
+def cleanup_browser(task_id: Optional[str] = None) -> None:
+    """Clean up browser session(s) for a task (task completion / inactivity timeout).
+
+    A bare task id reaps BOTH the primary session and any hybrid local sidecar
+    spawned for it; a key already carrying ``::local`` (inactivity loop) reaps
+    only that one.
+    """
+    _bt = _origin()
+    if task_id is None:
+        task_id = "default"
+
+    session_keys = [task_id]
+    if not _bt._is_local_sidecar_key(task_id):
+        sidecar_key = f"{task_id}{_bt._LOCAL_SUFFIX}"
+        with _bt._cleanup_lock:
+            if sidecar_key in _bt._active_sessions:
+                session_keys.append(sidecar_key)
+
+    for session_key in session_keys:
+        _bt._cleanup_single_browser_session(session_key)
+    _bt._drop_last_active_binding(task_id)
+
+
+def _kill_verified_daemon(socket_dir: str, session_name: str) -> bool:
+    """Tree-kill the daemon recorded in ``<socket_dir>/<session>.pid`` if it is verifiably ours.
+
+    The .pid file lives in a world-writable temp dir and PIDs recycle: the
+    process must pass ``_verify_reapable_browser_daemon`` and have a start-time
+    fingerprint (so the kill refuses if the PID is swapped between check and
+    kill). Returns True when a kill was issued. Never raises.
+    """
+    _bt = _origin()
+    pid_file = os.path.join(socket_dir, f"{session_name}.pid")
+    if not os.path.isfile(pid_file):
+        return False
+    try:
+        from tools.process_registry import ProcessRegistry
+        daemon_pid = int(Path(pid_file).read_text(encoding="utf-8").strip())
+        if not _bt._verify_reapable_browser_daemon(daemon_pid, socket_dir, session_name):
+            _bt.logger.debug(
+                "Skipped daemon kill for %s: pid %s failed identity "
+                "verification", session_name, daemon_pid)
+            return False
+        from gateway.status import get_process_start_time
+        daemon_start = get_process_start_time(daemon_pid)
+        if daemon_start is None:
+            _bt.logger.debug(
+                "Skipped daemon kill for %s: no start-time "
+                "fingerprint for pid %s", session_name, daemon_pid)
+            return False
+        ProcessRegistry._terminate_host_pid(daemon_pid, daemon_start)
+        _bt.logger.debug("Killed daemon pid %s for %s", daemon_pid, session_name)
+        return True
+    except (ProcessLookupError, ValueError, PermissionError, OSError):
+        _bt.logger.debug("Could not kill daemon pid for %s (already dead or inaccessible)", session_name)
+        return False
+
+
+def _release_session_resources(task_id: str, session_info: Dict[str, Any]) -> None:
+    """Untrack ``task_id``, close its cloud provider session, kill its daemon.
+
+    The unconditional tail of ``_cleanup_single_browser_session``; also the
+    whole of the janitor's force-reap path, which skips the polite
+    agent-browser/Camofox ``close`` that kept failing but must still release
+    the cloud session and the local Chromium.
+    """
+    _bt = _origin()
+    bb_session_id = session_info.get("bb_session_id", "unknown")
+    with _bt._cleanup_lock:
+        _bt._active_sessions.pop(task_id, None)
+        _bt._session_last_activity.pop(task_id, None)
+        _bt._session_owner_homes.pop(task_id, None)
+        _bt._cleanup_failures.pop(task_id, None)
+
+    # Cloud mode only — local sidecars have bb_session_id=None.
+    if bb_session_id:
+        provider = _bt._get_cloud_provider()
+        if provider is not None:
+            try:
+                provider.close_session(bb_session_id)
+            except Exception as e:
+                _bt.logger.warning("Could not close cloud browser session: %s", e)
+
+    session_name = session_info.get("session_name", "")
+    if session_name:
+        socket_dir = os.path.join(_bt._socket_safe_tmpdir(), f"agent-browser-{session_name}")
+        if os.path.exists(socket_dir):
+            _bt._kill_verified_daemon(socket_dir, session_name)
+            shutil.rmtree(socket_dir, ignore_errors=True)
+
+
+def _force_reap_browser_session(task_id: str) -> None:
+    """Janitor last resort after repeated cleanup failures.
+
+    Skips the ``close`` round-trips that keep failing and goes straight to
+    ``_release_session_resources`` (cloud close + daemon kill + untrack).
+    """
+    _bt = _origin()
+    _bt._stop_cdp_supervisor(task_id)
+    with _bt._cleanup_lock:
+        session_info = _bt._active_sessions.get(task_id)
+        _bt._session_last_activity.pop(task_id, None)
+        _bt._recording_sessions.discard(task_id)
+    if session_info:
+        _bt._release_session_resources(task_id, session_info)
+    _bt._drop_last_active_binding(task_id)
+
+
+def _cleanup_single_browser_session(task_id: str) -> None:
+    """Internal: reap a single browser session by its exact session key."""
+    # Stop the CDP supervisor for this task FIRST so we close our WebSocket
+    # before the backend tears down the underlying CDP endpoint.
+    _bt = _origin()
+    _bt._stop_cdp_supervisor(task_id)
+
+    # Also clean up Camofox session if running in Camofox mode.
+    # Skip full close when managed persistence is enabled — the browser
+    # profile (and its session cookies) must survive across agent tasks.
+    # The inactivity reaper still frees idle resources.
+    if _bt._is_camofox_mode():
+        try:
+            from tools.browser_camofox import camofox_close, camofox_soft_cleanup
+            if not camofox_soft_cleanup(task_id):
+                camofox_close(task_id)
+        except Exception as e:
+            _bt.logger.debug("Camofox cleanup for task %s: %s", task_id, e)
+
+    _bt.logger.debug("cleanup_browser called for task_id: %s", task_id)
+    _bt.logger.debug("Active sessions: %s", list(_bt._active_sessions.keys()))
+
+    # Check if session exists (under lock), but don't remove yet -
+    # _run_browser_command needs it to build the close command.
+    with _bt._cleanup_lock:
+        session_info = _bt._active_sessions.get(task_id)
+
+    if session_info:
+        bb_session_id = session_info.get("bb_session_id", "unknown")
+        _bt.logger.debug("Found session for task %s: bb_session_id=%s", task_id, bb_session_id)
+
+        # Stop auto-recording before closing (saves the file)
+        _bt._maybe_stop_recording(task_id)
+
+        # A Lightpanda session is a process Hermes spawned itself (Browser
+        # Use mode); there is no agent-browser daemon to send ``close`` to.
+        # An expired cloud CDP URL cannot accept an agent-browser close command.
+        # Avoid feeding it back through _get_session_info(), which would try to
+        # renew the session recursively while cleanup is still in progress.
+        if (session_info.get("features") or {}).get("lightpanda"):
+            try:
+                from tools.browser_lightpanda import stop_lightpanda
+
+                stop_lightpanda(session_info.get("session_name", ""))
+            except Exception as e:
+                _bt.logger.warning("lightpanda stop failed for task %s: %s", task_id, e)
+        elif _bt._session_has_expired(session_info):
+            _bt.logger.debug(
+                "Skipping agent-browser close for expired session %s", task_id
+            )
+        else:
+            try:
+                _bt._run_browser_command(task_id, "close", [], timeout=10)
+                _bt.logger.debug(
+                    "agent-browser close command completed for task %s", task_id
+                )
+            except Exception as e:
+                _bt.logger.warning("agent-browser close failed for task %s: %s", task_id, e)
+
+        _bt._release_session_resources(task_id, session_info)
+
+        _bt.logger.debug("Removed task %s from active sessions", task_id)
+    else:
+        _bt.logger.debug("No active session found for task_id: %s", task_id)
+
+
+def cleanup_all_browsers() -> None:
+    """
+    Clean up all active browser sessions.
+
+    Useful for cleanup on shutdown.
+    """
+    _bt = _origin()
+    with _bt._cleanup_lock:
+        task_ids = list(_bt._active_sessions.keys())
+    for task_id in task_ids:
+        _bt.cleanup_browser(task_id)
+
+    # Tear down CDP supervisors for all tasks so background threads exit.
+    try:
+        from tools.browser_supervisor import SUPERVISOR_REGISTRY  # type: ignore[import-not-found]
+        SUPERVISOR_REGISTRY.stop_all()
+    except Exception:
+        pass
+
+    # Reset cached lookups so they are re-evaluated on next use.
+    _bt._cached_agent_browser = None
+    _bt._agent_browser_resolved = False
+    _bt._discover_homebrew_node_dirs.cache_clear()
+    # Flip the resolved flag BEFORE nulling the cache so a concurrent
+    # reader never sees ``resolved=True`` with ``cache=None``.
+    _bt._command_timeout_resolved = False
+    _bt._cached_command_timeout = None
+    _bt._snapshot_threshold_resolved = False
+    _bt._cached_snapshot_threshold = None
+    _bt._cached_chromium_installed = None
+    _bt._chromium_autoinstall_attempted = False
+    _bt._cached_browser_engine = None
+    _bt._browser_engine_resolved = False
diff --git a/tools/browser_tool_lightpanda_fallback.py b/tools/browser_tool_lightpanda_fallback.py
index 3f13c402bf..15cadb5765 100644
--- a/tools/browser_tool_lightpanda_fallback.py
+++ b/tools/browser_tool_lightpanda_fallback.py
@@ -58,8 +58,7 @@ def lightpanda_engine_status() -> Tuple[bool, str]:
     if bu_mode:
         try:
             from tools.browser_use_cli import (
-                _read_browser_cfg,
-                is_legacy_browser_use_cloud_config,
+                _read_browser_cfg, is_legacy_browser_use_cloud_config
             )
 
             if is_legacy_browser_use_cloud_config(_read_browser_cfg()):
@@ -131,16 +130,13 @@ def _needs_lightpanda_fallback(engine: str, command: str, result: Dict[str, Any]
 def _annotate_lightpanda_fallback(result: Dict[str, Any], reason: str) -> Dict[str, Any]:
     """Add a user-visible Chrome fallback warning to a browser command result."""
     warning = (
-        "⚠ Lightpanda fallback: Chrome was used for this browser action. "
-        f"{reason}"
+        "⚠ Lightpanda fallback: Chrome was used for this browser action. " f"{reason}"
     )
     annotated = dict(result)
     annotated["fallback_warning"] = warning
     annotated["browser_engine"] = "chrome"
     annotated["browser_engine_fallback"] = {
-        "from": "lightpanda",
-        "to": "chrome",
-        "reason": reason,
+        "from": "lightpanda", "to": "chrome", "reason": reason
     }
     data = annotated.get("data")
     if isinstance(data, dict):
@@ -148,8 +144,7 @@ def _annotate_lightpanda_fallback(result: Dict[str, Any], reason: str) -> Dict[s
         data.setdefault("fallback_warning", warning)
         data.setdefault("browser_engine", "chrome")
         data.setdefault(
-            "browser_engine_fallback",
-            {"from": "lightpanda", "to": "chrome", "reason": reason},
+            "browser_engine_fallback", {"from": "lightpanda", "to": "chrome", "reason": reason}
         )
         annotated["data"] = data
     return annotated
@@ -165,10 +160,7 @@ def _copy_fallback_warning(target: Dict[str, Any], result: Dict[str, Any]) -> Di
 
 
 def _run_chrome_fallback_command(
-    task_id: str,
-    command: str,
-    args: List[str],
-    timeout: int,
+    task_id: str, command: str, args: List[str], timeout: int
 ) -> Dict[str, Any]:
     """Run a browser command in a temporary Chrome session at the current URL.
 
@@ -259,9 +251,7 @@ def _run_chrome_fallback_command(
 
 
 def _chrome_fallback_screenshot(
-    task_id: str,
-    args: List[str],
-    timeout: int,
+    task_id: str, args: List[str], timeout: int
 ) -> Dict[str, Any]:
     """Take a screenshot using a temporary Chrome session."""
     _bt = _origin()
diff --git a/tools/browser_tool_origin.py b/tools/browser_tool_origin.py
index 6d5ebf2288..b6cf05fec7 100644
--- a/tools/browser_tool_origin.py
+++ b/tools/browser_tool_origin.py
@@ -60,7 +60,10 @@ def origin_module():
        (``from tools import browser_tool`` in a test that calls the helper directly);
     3. ``sys.modules`` / the ``tools`` package attribute / a fresh import.
     """
-    start = sys._getframe(2)
+    try:
+        start = sys._getframe(2)
+    except ValueError:  # called directly by the interpreter (atexit callback)
+        start = None
     frame = start
     while frame is not None:
         if frame.f_globals.get("__name__") == _ORIGIN_NAME:
diff --git a/tools/browser_tool_real_profile.py b/tools/browser_tool_real_profile.py
index 6d3f67d6c7..29a976d63b 100644
--- a/tools/browser_tool_real_profile.py
+++ b/tools/browser_tool_real_profile.py
@@ -332,10 +332,7 @@ def _real_profile_cdp() -> tuple:
         )
 
     from hermes_cli.browser_connect import (
-        chromium_executable,
-        detect_default_chromium,
-        real_profile_copy_dir,
-        snapshot_real_profile,
+        chromium_executable, detect_default_chromium, real_profile_copy_dir, snapshot_real_profile
     )
 
     with _bt._real_profile_cdp_lock:
diff --git a/tools/browser_tool_session.py b/tools/browser_tool_session.py
new file mode 100644
index 0000000000..bf6d3f56a3
--- /dev/null
+++ b/tools/browser_tool_session.py
@@ -0,0 +1,809 @@
+"""agent-browser session management: daemon spawn, per-backend session creation (local/lightpanda/cdp/cloud), cached session lookup, command execution with timeout handling and output interpretation.
+
+Split out of ``tools/browser_tool.py``; every name is re-imported there so
+``tools.browser_tool.<name>`` keeps resolving (and monkeypatching). Origin
+symbols and module state are read/written through ``_bt`` (the origin module,
+resolved per call by :func:`tools.browser_tool_origin.origin_module`) so
+``patch("tools.browser_tool.X")`` is honoured and no import cycle exists.
+"""
+
+import json
+import logging
+import os
+import shutil
+import subprocess
+from pathlib import Path
+from typing import Any, Dict, List, Optional
+
+from tools.browser_tool_origin import origin_module as _origin
+
+
+def _needs_chromium_sandbox_bypass() -> bool:
+    """Return True when Chromium needs --no-sandbox to start reliably."""
+    _bt = _origin()
+    if hasattr(os, "geteuid") and os.geteuid() == 0:
+        return True
+    if _bt._running_in_docker():
+        return True
+    userns_restrict = "/proc/sys/kernel/apparmor_restrict_unprivileged_userns"
+    try:
+        with open(userns_restrict, encoding="utf-8") as f:
+            if f.read().strip() == "1":
+                return True
+    except OSError:
+        pass
+    return False
+
+
+def _apply_chromium_sandbox_args(browser_env: Dict[str, str]) -> None:
+    """Add required Chromium sandbox flags without overriding user settings."""
+    _bt = _origin()
+    if (
+        "AGENT_BROWSER_ARGS" not in browser_env
+        and "AGENT_BROWSER_CHROME_FLAGS" not in browser_env
+        and _bt._needs_chromium_sandbox_bypass()
+    ):
+        _bt.logger.debug(
+            "browser: sandbox bypass needed (root/docker/AppArmor userns) — "
+            "injecting --no-sandbox"
+        )
+        browser_env["AGENT_BROWSER_ARGS"] = "--no-sandbox,--disable-dev-shm-usage"
+
+
+def _read_command_output_files(stdout_path: str, stderr_path: str) -> tuple[str, str]:
+    """Best-effort read of agent-browser stdout/stderr temp files."""
+    stdout = stderr = ""
+    for path, slot in ((stdout_path, "stdout"), (stderr_path, "stderr")):
+        try:
+            with open(path, "r", encoding="utf-8") as f:
+                text = f.read().strip()
+        except OSError:
+            continue
+        if slot == "stdout":
+            stdout = text
+        else:
+            stderr = text
+    return stdout, stderr
+
+
+def _unlink_command_output_files(*paths: str) -> None:
+    for path in paths:
+        try:
+            os.unlink(path)
+        except OSError:
+            pass
+
+
+def _format_browser_timeout_error(
+    command: str, timeout: int, stdout: str, stderr: str
+) -> str:
+    """Build an actionable timeout message from captured daemon output."""
+    _bt = _origin()
+    parts = [f"Command timed out after {timeout} seconds"]
+    detail = (stderr or stdout or "").strip()
+    if detail:
+        parts.append(detail[:1500])
+
+    combined = f"{stderr}\n{stdout}".lower()
+    hints: list[str] = []
+    if "sandbox" in combined:
+        hints.append(
+            "Chromium sandbox launch failed. Set AGENT_BROWSER_ARGS="
+            "'--no-sandbox,--disable-dev-shm-usage' in your environment, "
+            "or run: npx agent-browser install --with-deps"
+        )
+    elif command == "open" and _bt._is_local_mode():
+        if _bt._running_in_docker():
+            hints.append(
+                "The browser daemon may still be starting or Chromium may be "
+                "missing. Pull the latest image: "
+                "docker pull ghcr.io/nousresearch/hermes-agent:latest"
+            )
+        else:
+            hints.append(
+                "The browser daemon may still be starting, or Chromium may be "
+                "missing system libraries. Install/repair with: "
+                "npx agent-browser install --with-deps "
+                "(or: npx playwright install --with-deps chromium)"
+            )
+    if hints:
+        parts.extend(hints)
+    return "\n".join(parts)
+
+
+def _agent_browser_argv(browser_cmd: str) -> list:
+    """Command prefix to invoke agent-browser (concrete binary or npx sentinel).
+
+    Concrete executable paths stay a single argv item (spaces intact); only the
+    synthetic npx sentinel expands. npx is resolved through the same
+    PATH + extended-PATH cascade ``_find_agent_browser`` uses — a bare
+    ``shutil.which("npx")`` would let a broken system npx shadow a healthy
+    Hermes-managed one. If npx isn't found at all (Termux, bare container) the
+    bare name is used so Popen raises a readable ``FileNotFoundError: 'npx'``.
+    ``--ignore-scripts``: AGENT_BROWSER_NPX_SPEC is a floating range, not an
+    exact pin — a compromised future patch must not run install-time scripts.
+    """
+    _bt = _origin()
+    if _bt._is_npx_agent_browser_sentinel(browser_cmd):
+        _npx_bin = _bt._resolve_npx_bin() or "npx"
+        return [_npx_bin, "--ignore-scripts", "--prefer-offline", "-y", _bt.AGENT_BROWSER_NPX_SPEC]
+    return [browser_cmd]
+
+
+def _prepare_session_socket_dir(session_name: str) -> str:
+    """Create the per-session agent-browser socket dir and claim it with our PID.
+
+    Each session gets its own dir so parallel workers don't fight over the
+    default socket path ("Failed to create socket directory: Permission
+    denied"). The owner_pid file is written BEFORE first use: another hermes
+    process's orphan reaper rmtree's any agent-browser-* dir in the shared
+    tmpdir that carries no live owner, which would delete this one mid-command.
+    """
+    _bt = _origin()
+    socket_dir = os.path.join(_bt._socket_safe_tmpdir(), f"agent-browser-{session_name}")
+    os.makedirs(socket_dir, mode=0o700, exist_ok=True)
+    _bt._write_owner_pid(socket_dir, session_name)
+    return socket_dir
+
+
+def _agent_browser_command_env(socket_dir: str) -> Dict[str, str]:
+    """Credential-scrubbed env for one agent-browser command.
+
+    Adds the discovery-time PATH fallbacks, the session socket dir, and the
+    daemon-side idle self-termination (``AGENT_BROWSER_IDLE_TIMEOUT_MS``,
+    agent-browser 0.24+) mirroring the Python-side inactivity janitor —
+    unless the user set the idle timeout explicitly.
+    """
+    _bt = _origin()
+    env = _bt._build_browser_env()
+    env["PATH"] = _bt._merge_browser_path(env.get("PATH", ""))
+    env["AGENT_BROWSER_SOCKET_DIR"] = socket_dir
+    if "AGENT_BROWSER_IDLE_TIMEOUT_MS" not in env:
+        env["AGENT_BROWSER_IDLE_TIMEOUT_MS"] = str(_bt.BROWSER_SESSION_INACTIVITY_TIMEOUT * 1000)
+    return env
+
+
+def _popen_agent_browser(argv: List[str], env: Dict[str, str], socket_dir: str, tag: str) -> "subprocess.Popen":
+    """Spawn agent-browser with stdout/stderr redirected to ``socket_dir/_stdout_<tag>``.
+
+    Temp files instead of pipes: the CLI forks a background daemon that inherits
+    its fds, so with pipes ``communicate()`` never sees EOF until the timeout.
+    Windows: CREATE_NO_WINDOW only (NOT CREATE_NEW_PROCESS_GROUP, which on
+    Python 3.11 cancels asyncio's running loop task and surfaces as
+    KeyboardInterrupt in the CLI), STARTF_USESTDHANDLES so CreateProcess hands
+    the child ONLY our three handles (leaked parent console handles make the
+    Rust binary's daemon grandchild die silently), close_fds=True for the rest.
+    Returns the Popen; the caller reads/unlinks the two files.
+    """
+    _bt = _origin()
+    stdout_path = os.path.join(socket_dir, f"_stdout_{tag}")
+    stderr_path = os.path.join(socket_dir, f"_stderr_{tag}")
+    stdout_fd = os.open(stdout_path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
+    stderr_fd = os.open(stderr_path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
+    try:
+        _popen_extra: dict = {}
+        if os.name == "nt":
+            _popen_extra["creationflags"] = _bt.windows_hide_flags()
+            _popen_extra["close_fds"] = True
+            _si = subprocess.STARTUPINFO()
+            _si.dwFlags |= subprocess.STARTF_USESTDHANDLES
+            _popen_extra["startupinfo"] = _si
+        return subprocess.Popen(
+            argv, stdout=stdout_fd, stderr=stderr_fd,
+            stdin=subprocess.DEVNULL, env=env, **_popen_extra,
+        )
+    finally:
+        os.close(stdout_fd)
+        os.close(stderr_fd)
+
+
+def _create_local_session(task_id: str, allow_real_profile: bool = True) -> Dict[str, str]:
+    _bt = _origin()
+    import uuid
+
+    # Real-profile consent: attach this local session (via CDP) to the user's
+    # browser running on a hermes-owned SNAPSHOT of their real profile, logins
+    # included. Fail closed on resolver/launch errors — a consented user must
+    # never be silently downgraded to a throwaway. The hybrid private-URL
+    # sidecar passes allow_real_profile=False: handing the user's cookie jar to
+    # an arbitrary internal host the model chose is a larger, unconsented
+    # exposure than the routing rule protects against (and a real-profile
+    # failure must not break private-URL routing).
+    if allow_real_profile:
+        cdp_url, err = _bt._real_profile_cdp()
+        if err:
+            raise RuntimeError(err)
+        if cdp_url:
+            session_name = f"rp_{uuid.uuid4().hex[:10]}"
+            _bt.logger.info(
+                "Created real-profile local session %s for task %s", session_name, task_id
+            )
+            return {
+                "session_name": session_name,
+                "bb_session_id": None,
+                "cdp_url": _bt._resolve_cdp_override(cdp_url),
+                "features": {"local": True, "real_profile": True},
+            }
+
+    # Browser Use mode drives whatever CDP endpoint it is handed; with
+    # ``browser.engine: lightpanda`` that endpoint is a Hermes-spawned
+    # ``lightpanda serve``. The built-in tools never reach this branch —
+    # they are hidden in Browser Use mode — and keep driving Lightpanda via
+    # ``agent-browser --engine lightpanda`` on the plain local session below.
+    if _bt._is_browser_use_cli_mode() and _bt._using_lightpanda_engine():
+        return _bt._create_lightpanda_session(task_id)
+
+    session_name = f"h_{uuid.uuid4().hex[:10]}"
+    _bt.logger.info("Created local browser session %s for task %s",
+                session_name, task_id)
+    return {
+        "session_name": session_name,
+        "bb_session_id": None,
+        "cdp_url": None,
+        "features": {"local": True},
+    }
+
+
+def _create_lightpanda_session(task_id: str) -> Dict[str, Any]:
+    """Spawn ``lightpanda serve`` for this session key (Browser Use mode)."""
+    _bt = _origin()
+    import uuid
+    from tools.browser_lightpanda import launch_lightpanda
+
+    session_name = f"lp_{uuid.uuid4().hex[:10]}"
+    server, err = launch_lightpanda(
+        session_name, block_private_networks=not _bt._is_local_backend()
+    )
+    if err:
+        raise RuntimeError(err)
+    _bt.logger.info(
+        "Created Lightpanda session %s (port %s) for task %s", session_name, server.port, task_id
+    )
+    return {
+        "session_name": session_name,
+        "bb_session_id": None,
+        "cdp_url": server.cdp_url,
+        "features": {"local": True, "lightpanda": True},
+    }
+
+
+def _local_backend_process_dead(session_info: Dict[str, Any]) -> bool:
+    """True for a Lightpanda session whose ``lightpanda serve`` is gone."""
+    if not (session_info.get("features") or {}).get("lightpanda"):
+        return False
+    from tools.browser_lightpanda import get_server
+
+    server = get_server(session_info.get("session_name", ""))
+    return server is None or not server.is_alive()
+
+
+def _create_cdp_session(task_id: str, cdp_url: str) -> Dict[str, str]:
+    """Create a session that connects to a user-supplied CDP endpoint."""
+    _bt = _origin()
+    import uuid
+    session_name = f"cdp_{uuid.uuid4().hex[:10]}"
+    _bt.logger.info("Created CDP browser session %s → %s for task %s",
+                session_name, _bt._sanitize_url_for_logs(cdp_url), task_id)
+    return {
+        "session_name": session_name,
+        "bb_session_id": None,
+        "cdp_url": cdp_url,
+        "features": {"cdp_override": True},
+    }
+
+
+def _create_cloud_session_or_fallback(task_id: str, provider) -> Dict[str, Any]:
+    """Create a cloud session; fall back to local Chromium (marked degraded) on failure.
+
+    Some cloud providers (Browser-Use v3) return an HTTP CDP discovery URL
+    instead of a raw websocket endpoint, so ``cdp_url`` is resolved here.
+    """
+    _bt = _origin()
+    try:
+        session_info = provider.create_session(task_id)
+        if not session_info or not isinstance(session_info, dict):
+            raise ValueError(f"Cloud provider returned invalid session: {session_info!r}")
+        if session_info.get("cdp_url"):
+            session_info = dict(session_info)
+            session_info["cdp_url"] = _bt._resolve_cdp_override(str(session_info["cdp_url"]))
+        return session_info
+    except Exception as e:
+        provider_name = type(provider).__name__
+        _bt.logger.warning(
+            "Cloud provider %s failed (%s); attempting fallback to local "
+            "Chromium for task %s",
+            provider_name, e, task_id,
+            exc_info=True,
+        )
+        try:
+            session_info = _bt._create_local_session(task_id)
+        except Exception as local_error:
+            raise RuntimeError(
+                f"Cloud provider {provider_name} failed ({e}) and local "
+                f"fallback also failed ({local_error})"
+            ) from e
+        # Mark session as degraded for observability
+        if isinstance(session_info, dict):
+            session_info = dict(session_info)
+            session_info["fallback_from_cloud"] = True
+            session_info["fallback_reason"] = str(e)
+            session_info["fallback_provider"] = provider_name
+        return session_info
+
+
+def _create_session_for_key(task_id: str, force_local: bool) -> Dict[str, Any]:
+    """Create a fresh session for ``task_id`` (runs OUTSIDE the lock: cloud mode makes a network call).
+
+    Precedence: CDP override > hybrid local sidecar > cloud provider > local.
+    The hybrid private-URL sidecar NEVER gets the real profile — presenting real
+    cookies to an arbitrary LAN host the model routed there is unconsented
+    exposure (see ``_create_local_session``).
+    """
+    _bt = _origin()
+    cdp_override = _bt._get_cdp_override()
+    if cdp_override and not force_local:
+        return _bt._create_cdp_session(task_id, cdp_override)
+    if force_local:
+        return _bt._create_local_session(task_id, allow_real_profile=False)
+    provider = _bt._get_cloud_provider()
+    if provider is None:
+        return _bt._create_local_session(task_id)
+    return _bt._create_cloud_session_or_fallback(task_id, provider)
+
+
+def _get_session_info(task_id: Optional[str] = None) -> Dict[str, Any]:
+    """Get or create session info for a session key (thread-safe).
+
+    ``task_id`` may carry the ``::local`` suffix (hybrid local sidecar), which
+    forces a local Chromium even when a cloud provider is configured. Also
+    starts the inactivity cleanup thread and touches activity tracking.
+    Returns a dict with ``session_name`` (always) plus ``bb_session_id`` /
+    ``cdp_url`` for cloud sessions.
+    """
+    _bt = _origin()
+    if task_id is None:
+        task_id = "default"
+
+    # Start the cleanup thread if not running (handles inactivity timeouts)
+    _bt._start_browser_cleanup_thread()
+
+    # Update activity timestamp for this session
+    _bt._update_session_activity(task_id)
+
+    with _bt._cleanup_lock:
+        # Check if we already have a session for this task
+        existing_session = _bt._active_sessions.get(task_id)
+
+    # Suspect-session recycle: a previous command
+    # timeout marked this cached session suspect via the SuspectableBackend
+    # adapter.  ensure_healthy() tears it down here, at next use, and we fall
+    # through to create a fresh session — the expensive recycle lives on this
+    # path, not on the timeout path (mark must stay cheap).
+    if existing_session is not None and not _bt._browser_session_backend(task_id).ensure_healthy():
+        # Teardown removes the activity entry; the replacement must be
+        # tracked by the inactivity reaper like an initial session.
+        _bt._update_session_activity(task_id)
+        with _bt._cleanup_lock:
+            replacement = _bt._active_sessions.get(task_id)
+        if replacement is not None and replacement is not existing_session:
+            # Another thread already recycled and re-created it.
+            return replacement
+        existing_session = None
+
+    if existing_session is not None:
+        if (
+            not _bt._session_has_expired(existing_session)
+            and not _bt._local_backend_process_dead(existing_session)
+        ):
+            return existing_session
+
+        _bt.logger.info(
+            "Replacing expired or dead browser session for task %s", task_id
+        )
+        _bt._cleanup_single_browser_session(task_id)
+        # Cleanup removes the activity entry. The replacement session must be
+        # tracked by the inactivity reaper just like an initial session.
+        _bt._update_session_activity(task_id)
+
+        # Guard against a concurrent replacement: another thread may have
+        # already cleaned up the expired session and created a fresh one
+        # while we were waiting.  If so, return the live replacement instead
+        # of falling through to create yet another session.
+        with _bt._cleanup_lock:
+            replacement = _bt._active_sessions.get(task_id)
+        if replacement is not None and replacement is not existing_session:
+            return replacement
+
+    # Hybrid routing: session keys ending with ``::local`` force a local
+    # Chromium regardless of the globally-configured cloud provider.  Public
+    # URLs in the same conversation continue to use the cloud session under
+    # the bare task_id key.
+    force_local = _bt._is_local_sidecar_key(task_id)
+    session_info = _bt._create_session_for_key(task_id, force_local)
+
+    with _bt._cleanup_lock:
+        # Double-check: another thread may have created a session while we
+        # were doing the network call. Use the existing one to avoid leaking
+        # orphan cloud sessions.
+        if task_id in _bt._active_sessions:
+            return _bt._active_sessions[task_id]
+        session_info = dict(session_info)
+        session_info.setdefault("session_key", task_id)
+        session_info.setdefault("owner_task_id", _bt._bare_task_id_for_session_key(task_id))
+        _bt._active_sessions[task_id] = session_info
+        # A brand-new session is healthy by definition — drop any stale
+        # suspect flag left by a wedged-path eviction of its predecessor.
+        _bt._suspect_browser_sessions.pop(task_id, None)
+
+    # Lazy-start the CDP supervisor now that the session exists (if the
+    # backend surfaces a CDP URL via override or session_info["cdp_url"]).
+    # Idempotent; swallows errors. See _ensure_cdp_supervisor for details.
+    # Skip for local sidecars — they have no CDP URL — and for Lightpanda
+    # sessions: those only exist in Browser Use mode, where the browser_*
+    # tools that consume supervisor state are hidden, so the supervisor
+    # would just hold an idle second CDP connection to the process.
+    if not force_local and not (session_info.get("features") or {}).get("lightpanda"):
+        _bt._ensure_cdp_supervisor(task_id)
+
+    return session_info
+
+
+def _discard_timed_out_browser_session(
+    task_id: str, session_info: Dict[str, Any], task_socket_dir: str
+) -> None:
+    """Drop a stuck client generation without losing cloud cleanup state."""
+    _bt = _origin()
+    with _bt._cleanup_lock:
+        if _bt._active_sessions.get(task_id) is not session_info:
+            return
+        _bt._stop_cdp_supervisor(task_id)
+        if session_info.get("bb_session_id") or session_info.get("cdp_url"):
+            import uuid
+            replacement = dict(session_info)
+            replacement["session_name"] = f"h_{uuid.uuid4().hex[:10]}"
+            replacement.pop("_first_nav", None)
+            _bt._active_sessions[task_id] = replacement
+        else:
+            _bt._active_sessions.pop(task_id, None)
+            _bt._session_last_activity.pop(task_id, None)
+
+        bare_task_id = _bt._bare_task_id_for_session_key(task_id)
+        if _bt._last_active_session_key.get(bare_task_id) == task_id:
+            _bt._last_active_session_key.pop(bare_task_id, None)
+
+    session_name = str(session_info.get("session_name") or "")
+    if session_name:
+        pid_file = os.path.join(task_socket_dir, f"{session_name}.pid")
+        if os.path.isfile(pid_file):
+            try:
+                daemon_pid = int(Path(pid_file).read_text(encoding="utf-8").strip())
+                if not _bt._verify_reapable_browser_daemon(daemon_pid, task_socket_dir, session_name):
+                    return
+                # Tree-kill: the daemon spawns Chromium
+                # children; terminating only the daemon PID leaks the whole
+                # Chromium tree.  agent.deadline.kill_process_tree escalates
+                # SIGTERM → SIGKILL across the tree.
+                from agent import deadline as _deadline
+
+                _deadline.kill_process_tree(daemon_pid)
+            except (ProcessLookupError, ValueError, PermissionError, OSError):
+                _bt.logger.debug("Could not kill timed-out browser daemon for %s", session_name)
+                return
+    shutil.rmtree(task_socket_dir, ignore_errors=True)
+
+
+def _read_browser_daemon_pid(task_socket_dir: str, session_name: str) -> Optional[int]:
+    """Read the agent-browser daemon PID for a session (best-effort)."""
+    pid_file = os.path.join(task_socket_dir, f"{session_name}.pid")
+    try:
+        return int(Path(pid_file).read_text(encoding="utf-8").strip())
+    except (OSError, ValueError):
+        return None
+
+
+def _browser_daemon_responsive(task_socket_dir: str, probe_timeout_s: float = 1.0) -> bool:
+    """Cheap liveness probe: connect to the daemon's unix control socket.
+
+    A successful connect proves the accept loop is alive (the command wedged on
+    the page/CDP side, not the daemon). Windows uses named pipes — no probe is
+    possible, so report unresponsive (tree-kill + respawn is the safe recovery).
+    """
+    if os.name == "nt":
+        return False
+    import socket as socket_mod
+
+    if not hasattr(socket_mod, "AF_UNIX"):
+        return False
+    try:
+        entries = os.listdir(task_socket_dir)
+    except OSError:
+        return False
+    sock_paths = [
+        os.path.join(task_socket_dir, e) for e in entries if e.endswith(".sock")
+    ]
+    for sock_path in sock_paths:
+        try:
+            with socket_mod.socket(socket_mod.AF_UNIX, socket_mod.SOCK_STREAM) as s:
+                s.settimeout(probe_timeout_s)
+                s.connect(sock_path)
+                return True
+        except OSError:
+            continue
+    return False
+
+
+def _handle_browser_command_timeout(
+    task_id: str, session_info: Dict[str, Any], task_socket_dir: str
+) -> None:
+    """Recover session state after a browser command timeout.
+
+    * Cloud / CDP sessions: no local daemon to probe — replace the stuck client
+      generation now (fresh ``session_name``, same ``bb_session_id`` so cloud
+      cleanup still works).
+    * Local daemon alive (PID live, identity-verified, control socket accepts):
+      only the *command* wedged; mark the session suspect and let the next use
+      recycle it via ``ensure_healthy`` → clean ``close`` → fresh session.
+    * Local daemon wedged/dead: it cannot service a clean close and its Chromium
+      children would leak — tree-kill and evict now; the next call respawns.
+
+    Both local branches ``mark_suspect`` first (cheap, lock-free) so the
+    poisoned-cache invariant holds even if eviction races another thread's
+    replacement (the flag then costs one harmless no-op teardown).
+    """
+    _bt = _origin()
+    if session_info.get("bb_session_id") or session_info.get("cdp_url"):
+        _bt._discard_timed_out_browser_session(task_id, session_info, task_socket_dir)
+        return
+
+    _bt._browser_session_backend(task_id).mark_suspect(
+        "browser command timed out; session may be poisoned"
+    )
+
+    session_name = str(session_info.get("session_name") or "")
+    daemon_pid = _bt._read_browser_daemon_pid(task_socket_dir, session_name) if session_name else None
+    daemon_alive = (
+        daemon_pid is not None
+        and _bt._pid_exists(daemon_pid)
+        and _bt._verify_reapable_browser_daemon(daemon_pid, task_socket_dir, session_name)
+        and _bt._browser_daemon_responsive(task_socket_dir)
+    )
+    if daemon_alive:
+        _bt.logger.warning(
+            "browser daemon for %s is alive after command timeout; session "
+            "marked suspect and will be recycled at next use", task_id,
+        )
+        return
+
+    _bt.logger.warning(
+        "browser daemon for %s is wedged or dead after command timeout; "
+        "tree-killing and evicting the session", task_id,
+    )
+    _bt._discard_timed_out_browser_session(task_id, session_info, task_socket_dir)
+    # The poisoned entry is gone (evicted, or superseded by a concurrent
+    # replacement discard refused to touch) — either way the cache no longer
+    # holds the timed-out session, so drop the flag: it must not poison a
+    # session created later under the same key.
+    _bt._suspect_browser_sessions.pop(task_id, None)
+
+
+def _interpret_browser_command_output(command: str, stdout: str, stderr: str, returncode: int) -> Dict[str, Any]:
+    """Turn a finished agent-browser process's output into a result dict.
+
+    Empty stdout with rc=0 is a broken state (stale daemon) and is reported as
+    failure rather than a silent ``{"success": True, "data": {}}`` — except for
+    commands in ``_EMPTY_OK_COMMANDS``. Non-JSON output is an error, except
+    for ``screenshot`` where the saved path is recovered from the prose.
+    """
+    _bt = _origin()
+    if stderr and stderr.strip():
+        level = logging.WARNING if returncode != 0 else logging.DEBUG
+        _bt.logger.log(level, "browser '%s' stderr: %s", command, stderr.strip()[:500])
+
+    stdout_text = stdout.strip()
+    if not stdout_text and returncode == 0 and command not in _bt._EMPTY_OK_COMMANDS:
+        _bt.logger.warning("browser '%s' returned empty output (rc=0)", command)
+        return {"success": False, "error": f"Browser command '{command}' returned no output"}
+    if not stdout_text:
+        if returncode != 0:
+            error_msg = stderr.strip() if stderr else f"Command failed with code {returncode}"
+            _bt.logger.warning("browser '%s' failed (rc=%s): %s", command, returncode, error_msg[:300])
+            return {"success": False, "error": error_msg}
+        return {"success": True, "data": {}}
+
+    try:
+        parsed = json.loads(stdout_text)
+    except json.JSONDecodeError:
+        raw = stdout_text[:2000]
+        _bt.logger.warning("browser '%s' returned non-JSON output (rc=%s): %s",
+                       command, returncode, raw[:500])
+        if command == "screenshot":
+            stderr_text = (stderr or "").strip()
+            combined_text = "\n".join(part for part in [stdout_text, stderr_text] if part)
+            recovered_path = _bt._extract_screenshot_path_from_text(combined_text)
+            if recovered_path and Path(recovered_path).exists():
+                _bt.logger.info(
+                    "browser 'screenshot' recovered file from non-JSON output: %s", recovered_path
+                )
+                return {"success": True, "data": {"path": recovered_path, "raw": raw}}
+        return {"success": False, "error": f"Non-JSON output from agent-browser for '{command}': {raw}"}
+
+    # Empty snapshot content is a common sign of daemon/CDP issues.
+    if command == "snapshot" and parsed.get("success"):
+        snap_data = parsed.get("data", {})
+        if not snap_data.get("snapshot") and not snap_data.get("refs"):
+            _bt.logger.warning("snapshot returned empty content. "
+                           "Possible stale daemon or CDP connection issue. "
+                           "returncode=%s", returncode)
+    return parsed
+
+
+def _run_browser_command(
+    task_id: str,
+    command: str,
+    args: List[str] = None,
+    timeout: Optional[int] = None,
+    _engine_override: Optional[str] = None,
+) -> Dict[str, Any]:
+    """Run one agent-browser CLI command against the task's session; returns its parsed JSON.
+
+    ``timeout=None`` reads ``browser.command_timeout`` (default 30s).
+    ``_engine_override`` forces an engine for this call only (the Lightpanda
+    fallback uses it to retry with Chrome without touching global state).
+    """
+    _bt = _origin()
+    if timeout is None:
+        timeout = _bt._safe_command_timeout()
+    args = args or []
+
+    # Build the command
+    try:
+        browser_cmd = _bt._find_agent_browser()
+    except FileNotFoundError as e:
+        _bt.logger.warning("agent-browser CLI not found: %s", e)
+        return {"success": False, "error": str(e)}
+
+    if _bt._requires_real_termux_browser_install(browser_cmd):
+        error = _bt._termux_browser_install_error()
+        _bt.logger.warning("browser command blocked on Termux: %s", error)
+        return {"success": False, "error": error}
+
+    # Local mode with no Chromium on disk: fail fast with an actionable
+    # message instead of hanging for _command_timeout seconds per call.
+    # Skip when engine=lightpanda — LP doesn't need Chromium for navigation.
+    if (
+        _bt._is_local_mode()
+        and not _bt._chromium_installed()
+        and _bt._get_browser_engine() != "lightpanda"
+        and not _bt._maybe_autoinstall_chromium()
+    ):
+        if _bt._running_in_docker():
+            hint = (
+                "Chromium browser is missing. You're running in Docker — pull "
+                "the latest image to get the bundled Chromium: "
+                "docker pull ghcr.io/nousresearch/hermes-agent:latest"
+            )
+        else:
+            hint = (
+                "Chromium browser is missing. Install it with: "
+                "npx agent-browser install --with-deps "
+                "(or: npx playwright install --with-deps chromium)"
+            )
+        _bt.logger.warning("browser command blocked: %s", hint)
+        return {"success": False, "error": hint}
+
+    from tools.interrupt import is_interrupted
+    if is_interrupted():
+        return {"success": False, "error": "Interrupted"}
+
+    # Get session info (creates Browserbase session with proxies if needed)
+    try:
+        session_info = _bt._get_session_info(task_id)
+    except Exception as e:
+        _bt.logger.warning("Failed to create browser session for task=%s: %s", task_id, e)
+        return {"success": False, "error": f"Failed to create browser session: {str(e)}"}
+    # Cleanup stops the supervisor before closing the backend; keep it stopped.
+    if command != "close" and session_info.get("cdp_url"):
+        _bt._ensure_cdp_supervisor(task_id)
+
+    # Build the command with the appropriate backend flag.
+    # Cloud mode: --cdp <websocket_url> connects to Browserbase.
+    # Local mode: --session <name> launches a local headless Chromium.
+    # The rest of the command (--json, command, args) is identical.
+    if session_info.get("cdp_url"):
+        # Cloud mode — connect to remote Browserbase browser via CDP
+        # IMPORTANT: Do NOT use --session with --cdp. In agent-browser >=0.13,
+        # --session creates a local browser instance and silently ignores --cdp.
+        backend_args = ["--cdp", session_info["cdp_url"]]
+    else:
+        # Local mode — launch Chromium (headless by default, headed when configured)
+        backend_args = ["--session", session_info["session_name"]]
+        if _bt._is_headed_mode():
+            backend_args.append("--headed")
+
+    # Lightpanda engine injection (local mode only, agent-browser v0.25.3+).
+    # Use the resolved session backend rather than global cloud-provider state:
+    # hybrid private-URL routing can create a local sidecar while a cloud
+    # provider remains configured for public URLs.
+    engine = _engine_override or _bt._get_browser_engine()
+    if engine != "auto" and not _bt._is_camofox_mode() and not session_info.get("cdp_url"):
+        backend_args += ["--engine", engine]
+
+    cmd_parts = _bt._agent_browser_argv(browser_cmd) + backend_args + ["--json", command] + args
+
+    try:
+        task_socket_dir = _bt._prepare_session_socket_dir(session_info["session_name"])
+        _bt.logger.debug("browser cmd=%s task=%s socket_dir=%s (%d chars)",
+                     command, task_id, task_socket_dir, len(task_socket_dir))
+        browser_env = _bt._agent_browser_command_env(task_socket_dir)
+
+        # Chromium-only launch flags are rejected by Lightpanda. Strip both
+        # the current and legacy variables for Lightpanda commands; explicit
+        # Chrome commands and fallback use the shared Chromium policy.
+        if engine == "lightpanda":
+            _stripped_args = browser_env.pop("AGENT_BROWSER_ARGS", None)
+            _stripped_flags = browser_env.pop("AGENT_BROWSER_CHROME_FLAGS", None)
+            if _stripped_args is not None or _stripped_flags is not None:
+                _bt.logger.debug(
+                    "browser: stripped Chromium-only AGENT_BROWSER_ARGS/"
+                    "AGENT_BROWSER_CHROME_FLAGS for Lightpanda command %s "
+                    "(agent-browser rejects them with --engine lightpanda)",
+                    command,
+                )
+        else:
+            _bt._apply_chromium_sandbox_args(browser_env)
+
+        stdout_path = os.path.join(task_socket_dir, f"_stdout_{command}")
+        stderr_path = os.path.join(task_socket_dir, f"_stderr_{command}")
+        proc = _bt._popen_agent_browser(cmd_parts, browser_env, task_socket_dir, command)
+
+        try:
+            proc.wait(timeout=timeout)
+        except subprocess.TimeoutExpired:
+            proc.kill()
+            proc.wait()
+            stdout, stderr = _bt._read_command_output_files(stdout_path, stderr_path)
+            _bt._unlink_command_output_files(stdout_path, stderr_path)
+            _bt._handle_browser_command_timeout(task_id, session_info, task_socket_dir)
+            if stderr and stderr.strip():
+                _bt.logger.warning(
+                    "browser '%s' stderr after timeout: %s", command, stderr.strip()[:500]
+                )
+            _bt.logger.warning("browser '%s' timed out after %ds (task=%s, socket_dir=%s)",
+                           command, timeout, task_id, task_socket_dir)
+            result = {
+                "success": False,
+                "error": _bt._format_browser_timeout_error(command, timeout, stdout, stderr),
+            }
+            # Fall through to fallback check below
+        else:
+            with open(stdout_path, "r", encoding="utf-8") as f:
+                stdout = f.read()
+            with open(stderr_path, "r", encoding="utf-8") as f:
+                stderr = f.read()
+            _bt._unlink_command_output_files(stdout_path, stderr_path)
+            result = _bt._interpret_browser_command_output(command, stdout, stderr, proc.returncode)
+
+    except Exception as e:
+        _bt.logger.warning("browser '%s' exception: %s", command, e, exc_info=True)
+        result = {"success": False, "error": str(e)}
+
+    # --- Lightpanda automatic Chrome fallback ---
+    # If engine is lightpanda and the result looks broken, retry with Chrome.
+    # This runs for ALL exit paths (timeout, empty, non-JSON, nonzero rc, parsed).
+    fallback_reason = _bt._lightpanda_fallback_reason(engine, command, result)
+    if fallback_reason:
+        _bt.logger.info(
+            "Lightpanda fallback: retrying '%s' with Chrome (task=%s): %s",
+            command,
+            task_id,
+            fallback_reason,
+        )
+        # For screenshots, use the dedicated Chrome fallback helper
+        # (spins up a separate Chrome session to the same URL).
+        if command == "screenshot":
+            fallback_result = _bt._chrome_fallback_screenshot(task_id, args or [], timeout)
+        else:
+            fallback_result = _bt._run_chrome_fallback_command(task_id, command, args, timeout)
+        return _bt._annotate_lightpanda_fallback(fallback_result, fallback_reason)
+
+    return result
diff --git a/tools/browser_tool_vision.py b/tools/browser_tool_vision.py
new file mode 100644
index 0000000000..10430fb37d
--- /dev/null
+++ b/tools/browser_tool_vision.py
@@ -0,0 +1,180 @@
+"""browser_vision helpers: Lightpanda pre-route, native provider vision, auxiliary-LLM screenshot analysis.
+
+Split out of ``tools/browser_tool.py``; every name is re-imported there so
+``tools.browser_tool.<name>`` keeps resolving (and monkeypatching). Origin
+symbols and module state are read/written through ``_bt`` (the origin module,
+resolved per call by :func:`tools.browser_tool_origin.origin_module`) so
+``patch("tools.browser_tool.X")`` is honoured and no import cycle exists.
+"""
+
+import os
+import shutil
+from pathlib import Path
+from typing import Any, Dict, Optional, Tuple
+
+from tools.browser_tool_origin import origin_module as _origin
+
+
+def _vision_mode_label() -> str:
+    _bt = _origin()
+    _cp = _bt._get_cloud_provider()
+    return "local" if _cp is None else f"cloud ({_cp.provider_name()})"
+
+
+def _lightpanda_vision_preroute(
+    effective_task_id: str, annotate: bool, screenshot_path: Path,
+) -> Tuple[bool, Optional[str], Path]:
+    """Capture the vision screenshot through the Chrome fallback when Lightpanda is the engine.
+
+    Lightpanda has no graphical renderer, so the normal path would fail with a
+    CDP error or return a placeholder PNG. Returns ``(prerouted, fallback_warning,
+    screenshot_path)``; on fallback failure ``prerouted`` is False and the caller
+    takes the normal screenshot path (forcing Chrome) so ``_run_browser_command``
+    still produces the standard fallback metadata/error.
+    """
+    _bt = _origin()
+    engine = _bt._get_browser_engine()
+    if engine != "lightpanda" or not _bt._should_inject_engine(engine):
+        return False, None, screenshot_path
+    _bt.logger.debug("browser_vision: pre-routing screenshot to Chrome (engine=lightpanda)")
+    screenshot_args = ["--annotate"] if annotate else []
+    fb_result = _bt._chrome_fallback_screenshot(effective_task_id, screenshot_args, _bt._get_command_timeout())
+    fb_result = _bt._annotate_lightpanda_fallback(fb_result, _bt._LP_VISION_FALLBACK_REASON)
+    if not fb_result.get("success"):
+        _bt.logger.warning("Lightpanda Chrome fallback vision screenshot failed: %s", fb_result.get("error"))
+        return False, None, screenshot_path
+    fb_path = fb_result.get("data", {}).get("path", "")
+    if fb_path and os.path.exists(fb_path):
+        import uuid as uuid_mod
+        from hermes_constants import get_hermes_dir
+
+        screenshots_dir = get_hermes_dir("cache/screenshots", "browser_screenshots")
+        screenshots_dir.mkdir(parents=True, exist_ok=True)
+        persistent_path = screenshots_dir / f"browser_screenshot_{uuid_mod.uuid4().hex}.png"
+        shutil.copy2(fb_path, persistent_path)
+        screenshot_path = persistent_path
+    return True, fb_result.get("fallback_warning"), screenshot_path
+
+
+def _native_vision_result(
+    screenshot_path: Path, question: str, annotate: bool,
+    result: Dict[str, Any], lp_fallback_warning: Optional[str],
+) -> Dict[str, Any]:
+    """Multimodal tool-result envelope: the main model inspects the pixels itself.
+
+    History-reuse cap: this embed is baked into the tool result and re-sent on
+    every later turn, exactly like vision_analyze's native path — apply the same
+    proactive resize so full-res screenshots can't enter immutable history
+    uncapped. The helper's stat/dimension quick-estimate skips the resize when
+    already under both caps; without Pillow it fails open to the raw bytes.
+    """
+    from tools.vision_tools import (
+        _EMBED_MAX_DIMENSION,
+        _EMBED_TARGET_BYTES,
+        _build_native_vision_tool_result,
+        _resize_image_for_vision,
+    )
+
+    data_url = _resize_image_for_vision(
+        screenshot_path,
+        mime_type="image/png",
+        max_base64_bytes=_EMBED_TARGET_BYTES,
+        max_dimension=_EMBED_MAX_DIMENSION,
+        force_jpeg=True,
+    )
+    native_result = _build_native_vision_tool_result(
+        image_url=str(screenshot_path),
+        question=question,
+        image_data_url=data_url,
+        image_size_bytes=screenshot_path.stat().st_size,
+    )
+    meta = native_result.setdefault("meta", {})
+    meta["screenshot_path"] = str(screenshot_path)
+    if lp_fallback_warning:
+        meta["fallback_warning"] = lp_fallback_warning
+    if annotate and result.get("data", {}).get("annotations"):
+        meta["annotations"] = result["data"]["annotations"]
+    native_result["text_summary"] = (
+        f"{native_result.get('text_summary', '')} " f"Screenshot path: {screenshot_path}"
+    ).strip()
+    return native_result
+
+
+def _analyze_screenshot_with_aux_llm(screenshot_path: Path, question: str) -> str:
+    """One-shot aux vision-LLM analysis (not baked into history), secret-redacted.
+
+    Encodes at full resolution; on a size-related provider rejection the image
+    is downscaled once and retried. Timeout/temperature come from
+    ``auxiliary.vision.*`` — local vision models (llama.cpp, ollama) can take
+    well over 30s, so the default timeout is generous.
+    """
+    _bt = _origin()
+    import base64
+
+    vision_prompt = (
+        f"You are analyzing a screenshot of a web browser.\n\n"
+        f"User's question: {question}\n\n"
+        f"Provide a detailed and helpful answer based on what you see in the screenshot. "
+        f"If there are interactive elements, describe them. If there are verification challenges "
+        f"or CAPTCHAs, describe what type they are and what action might be needed. "
+        f"Focus on answering the user's specific question."
+    )
+    _screenshot_bytes = screenshot_path.read_bytes()
+    _screenshot_b64 = base64.b64encode(_screenshot_bytes).decode("ascii")
+    data_url = f"data:image/png;base64,{_screenshot_b64}"
+    vision_model = _bt._get_vision_model()
+    _bt.logger.debug("browser_vision: analysing screenshot (%d bytes)",
+                 len(_screenshot_bytes))
+
+    vision_timeout = 120.0
+    vision_temperature = 0.1
+    try:
+        from hermes_cli.config import load_config
+        _vision_cfg = _bt.cfg_get(load_config(), "auxiliary", "vision", default={})
+        _vt = _vision_cfg.get("timeout")
+        if _vt is not None:
+            vision_timeout = float(_vt)
+        _vtemp = _vision_cfg.get("temperature")
+        if _vtemp is not None:
+            vision_temperature = float(_vtemp)
+    except Exception:
+        pass
+
+    call_kwargs = {
+        "task": "vision",
+        "messages": [
+            {
+                "role": "user",
+                "content": [
+                    {"type": "text", "text": vision_prompt},
+                    {"type": "image_url", "image_url": {"url": data_url}},
+                ],
+            }
+        ],
+        "temperature": vision_temperature,
+        "timeout": vision_timeout,
+    }
+    if vision_model:
+        call_kwargs["model"] = vision_model
+    try:
+        response = _bt._lazy_call_llm(**call_kwargs)
+    except Exception as _api_err:
+        from tools.vision_tools import (
+            _is_image_size_error, _resize_image_for_vision, _RESIZE_TARGET_BYTES,
+        )
+        if not (_is_image_size_error(_api_err) and len(data_url) > _RESIZE_TARGET_BYTES):
+            raise
+        _bt.logger.info(
+            "Vision API rejected screenshot (%.1f MB); "
+            "auto-resizing to ~%.0f MB and retrying...",
+            len(data_url) / (1024 * 1024),
+            _RESIZE_TARGET_BYTES / (1024 * 1024),
+        )
+        data_url = _resize_image_for_vision(screenshot_path, mime_type="image/png")
+        call_kwargs["messages"][0]["content"][1]["image_url"]["url"] = data_url
+        response = _bt._lazy_call_llm(**call_kwargs)
+
+    analysis = (response.choices[0].message.content or "").strip()
+    # Redact secrets the vision LLM may have read from the screenshot.
+    from agent.redact import redact_sensitive_text
+    return redact_sensitive_text(analysis)
diff --git a/tools/browser_use_cli.py b/tools/browser_use_cli.py
index d79bd6cd5a..7ce293f898 100644
--- a/tools/browser_use_cli.py
+++ b/tools/browser_use_cli.py
@@ -4,6 +4,7 @@ When browser.backend is "browser-use", the model gets ``browser_exec`` tool
 instead of default browser tools
 """
 
+import contextlib
 import importlib
 import json
 import logging
@@ -91,14 +92,20 @@ _URL_RE = re.compile(r"https?://[^\s'\"\\)]+", re.IGNORECASE)
 _FHS_BIN_DIRS = ("/usr/local/sbin", "/usr/local/bin", "/usr/sbin", "/usr/bin", "/sbin", "/bin")
 
 
+def _quiet(fn: Callable[[], Any], default: Any, log_prefix: str = "") -> Any:
+    """``fn()``, or ``default`` on any exception (debug-logged when ``log_prefix`` is set)."""
+    try:
+        return fn()
+    except Exception as e:
+        if log_prefix:
+            logger.debug("%s: %s", log_prefix, e)
+        return default
+
+
 def _lazy_call(module: str, name: str, default: Any, log_prefix: str) -> Any:
     """Call ``module.name()`` resolved at call time (so tests can stub the module or
     patch the attribute); on any failure log ``log_prefix`` and return ``default``."""
-    try:
-        return getattr(importlib.import_module(module), name)()
-    except Exception as e:
-        logger.debug("%s: %s", log_prefix, e)
-        return default
+    return _quiet(lambda: getattr(importlib.import_module(module), name)(), default, log_prefix)
 
 
 def _camofox_active(context: str = "") -> bool:
@@ -106,6 +113,16 @@ def _camofox_active(context: str = "") -> bool:
     return _lazy_call("tools.browser_camofox", "is_camofox_mode", False, f"Camofox activity check failed{context}")
 
 
+def _real_profile_consented() -> bool:
+    """Whether the user opted in to real-profile local browsing (config read)."""
+    return _lazy_call("tools.browser_tool", "_use_real_profile", False, "real-profile consent lookup failed")
+
+
+def _lightpanda_engine_in_use() -> bool:
+    return _lazy_call("tools.browser_tool", "lightpanda_engine_status", (False, ""),
+                      "lightpanda engine status unavailable")[0]
+
+
 def _set_cdp_env(env: dict, cdp: str) -> None:
     """Export a CDP endpoint under the BU_CDP_* contract (http(s) → URL, else WS)."""
     env["BU_CDP_URL" if cdp.startswith(("http://", "https://")) else "BU_CDP_WS"] = cdp
@@ -142,9 +159,9 @@ def _blocked_url_in_code(code: str) -> Optional[str]:
 def _base_subprocess_env() -> dict:
     from tools.browser_tool import _build_browser_env
     env = _build_browser_env()
-    # The CLI runs under its own Python (uv tool / uvx); inherited
-    # PYTHONPATH/PYTHONHOME (Hermes's venv) win over its site-packages → wrong-ABI
-    # C-extensions (pydantic_core) and a crash. Strip both.
+    # The CLI runs under its own Python (uv tool / uvx); inherited PYTHONPATH/PYTHONHOME
+    # (Hermes's venv) win over its site-packages → wrong-ABI C-extensions (pydantic_core)
+    # and a crash. Strip both.
     env.pop("PYTHONPATH", None)
     env.pop("PYTHONHOME", None)
     env["PATH"] = _floor_subprocess_path(env.get("PATH", ""))
@@ -153,24 +170,18 @@ def _base_subprocess_env() -> dict:
 
 
 def _floor_subprocess_path(path: str) -> str:
-    """Guarantee core system dirs survive onto the CLI subprocess PATH.
-
-    Profile workers (kanban bots, cron) can inherit a PATH of only version-manager
-    dirs; the uv browser-use binary's POSIX sh trampoline resolves
-    ``dirname``/``realpath`` through PATH and dies (exit 127) without /usr/bin.
-    Reuses browser_tool's ``_merge_browser_path`` floor, else appends FHS bin
-    dirs. Windows .cmd shims don't trampoline through PATH, so no-op there.
-    """
+    """Guarantee core system dirs survive onto the CLI subprocess PATH: profile workers
+    (kanban bots, cron) can inherit a PATH of only version-manager dirs, and the uv
+    browser-use binary's POSIX sh trampoline resolves ``dirname``/``realpath`` through
+    PATH and dies (exit 127) without /usr/bin. Reuses browser_tool's ``_merge_browser_path``
+    floor, else appends FHS bin dirs. Windows .cmd shims don't trampoline: no-op there."""
     if os.name == "nt":
         return path
-    try:
+    with contextlib.suppress(Exception):
         from tools.browser_tool import _merge_browser_path
         return _merge_browser_path(path or "")
-    except Exception:
-        pass
     parts = [p for p in (path or "").split(os.pathsep) if p]
-    existing = set(parts)
-    parts.extend(d for d in _FHS_BIN_DIRS if d not in existing and os.path.isdir(d))
+    parts.extend(d for d in _FHS_BIN_DIRS if d not in set(parts) and os.path.isdir(d))
     return os.pathsep.join(parts)
 
 
@@ -185,6 +196,10 @@ def _read_browser_cfg() -> dict:
         return {}
 
 
+def _use_gateway(browser_cfg: dict) -> bool:
+    return is_truthy_value(browser_cfg.get("use_gateway"), default=False)
+
+
 def get_browser_backend() -> str:
     """Return the configured browser backend key ("" = unset → default).
 
@@ -198,16 +213,14 @@ def get_browser_backend() -> str:
 
 
 def is_legacy_browser_use_cloud_config(browser_cfg: dict) -> bool:
-    """True for pre-CLI direct-API Browser Use cloud configs"""
+    """True for pre-CLI direct-API Browser Use cloud configs. An explicit backend or
+    a non-Browser-Use cloud_provider wins; Camofox is selected via env var, not
+    cloud_provider, so a Camofox user with a stray BROWSER_USE_API_KEY keeps it."""
     if not isinstance(browser_cfg, dict) or browser_cfg.get("backend"):
-        return False  # an explicit backend choice wins
-    provider = str(browser_cfg.get("cloud_provider") or "").strip().lower()
-    if provider not in {"browser-use", ""}:
-        return False  # explicit local/Browserbase/… choices win
-    if is_truthy_value(browser_cfg.get("use_gateway"), default=False):
         return False
-    # Camofox is selected via env var, not cloud_provider — a Camofox user
-    # with a stray BROWSER_USE_API_KEY must keep their explicit choice.
+    provider = str(browser_cfg.get("cloud_provider") or "").strip().lower()
+    if provider not in {"browser-use", ""} or _use_gateway(browser_cfg):
+        return False
     if _camofox_active(" during migration"):
         return False
     return bool(os.getenv("BROWSER_USE_API_KEY"))
@@ -217,21 +230,17 @@ def is_browser_use_cli_mode() -> bool:
     """True when the Browser Use CLI replaces the built-in browser stack.
 
     Browser Use mode is the DEFAULT: unset ``browser.backend`` ("") enables it
-    whenever the CLI is runnable (installed binary or uvx); ``browser.backend:
-    off`` (or ``/browser use off``) keeps the built-in browser_* tools. Camofox
-    always falls back to the built-in tools regardless — Firefox-based with a
-    custom HTTP API and no CDP surface, so the CDP-only harness cannot drive it.
+    whenever the CLI is runnable (installed binary or uvx), so browsing never
+    silently breaks; ``browser.backend: off`` (or ``/browser use off``) keeps the
+    built-in browser_* tools. Camofox always falls back to the built-in tools —
+    Firefox-based with a custom HTTP API and no CDP surface for the harness.
     """
     if _camofox_active():
         return False
     backend = get_browser_backend()
     if backend:
         return backend == _BACKEND_KEY
-    if is_legacy_browser_use_cloud_config(_read_browser_cfg()):
-        return True
-    # Default (backend unset): Browser Use mode when the CLI can run at all;
-    # otherwise keep the built-in tools so browsing never silently breaks.
-    return _find_cli() is not None
+    return is_legacy_browser_use_cloud_config(_read_browser_cfg()) or _find_cli() is not None
 
 
 _NOTICE_STAMP_NAME = ".browser_use_default_notice"
@@ -246,16 +255,12 @@ def default_downgrade_notice() -> Optional[str]:
         if get_browser_backend() or _camofox_active() or _find_cli() is not None:
             return None  # explicit choice / Camofox / CLI present — nothing downgraded
         stamp = Path(get_hermes_home()) / "cache" / _NOTICE_STAMP_NAME
-        try:
+        with contextlib.suppress(OSError):
             if 0 <= time.time() - stamp.stat().st_mtime < _NOTICE_INTERVAL_S:
                 return None
-        except OSError:
-            pass
-        try:
+        with contextlib.suppress(OSError):
             stamp.parent.mkdir(parents=True, exist_ok=True)
             stamp.touch()
-        except OSError:
-            pass
         return ("Browser Use CLI not found — using the built-in browser tools. "
                 "Run `hermes tools` (Browser Automation → Browser Use) to install it, "
                 "or `browser.backend: off` in config.yaml to silence this.")
@@ -296,27 +301,25 @@ def _find_cli() -> Optional[List[str]]:
 
 
 def install_cli(timeout_s: int = 600) -> Tuple[bool, str]:
-    """Install the browser-use CLI persistently via ``uv tool install``
-    (managed uv via ``ensure_uv`` → uv on PATH), linking the binary into
-    ``$HERMES_HOME/bin`` (``UV_TOOL_BIN_DIR``) so ``_find_cli()`` resolves it for
-    every profile without touching the user's PATH. Returns ``(ok, message)``;
-    never raises.
+    """Install the browser-use CLI persistently via ``uv tool install`` (managed uv
+    via ``ensure_uv`` → uv on PATH), linking the binary into ``$HERMES_HOME/bin``
+    (``UV_TOOL_BIN_DIR``) so ``_find_cli()`` resolves it for every profile without
+    touching the user's PATH. Returns ``(ok, message)``; never raises.
+
+    MANAGED-FIRST: only the managed copy short-circuits. A browser-use on PATH is a
+    user-level side install and must NOT prevent provisioning the canonical
+    Hermes-managed copy (version drift, no updates via hermes tools).
     """
-    # MANAGED-FIRST: only the managed copy short-circuits. A browser-use on PATH
-    # is a user-level side install and must NOT prevent provisioning the
-    # canonical Hermes-managed copy (version drift, no updates via hermes tools).
     bin_dir = _managed_bin_dir()
     managed = shutil.which("browser-use", path=bin_dir)
     if managed:
         return True, f"browser-use CLI already installed ({managed})"
 
-    uv_bin: Optional[str] = None
-    try:
+    def _managed_uv() -> Optional[str]:
         from hermes_cli.managed_uv import ensure_uv
-        uv_bin = str(ensure_uv() or "") or None
-    except Exception as e:
-        logger.debug("Managed uv bootstrap unavailable: %s", e)
-    uv_bin = uv_bin or shutil.which("uv")
+        return str(ensure_uv() or "") or None
+
+    uv_bin = _quiet(_managed_uv, None, "Managed uv bootstrap unavailable") or shutil.which("uv")
     if not uv_bin:
         return False, ("uv is not available and could not be bootstrapped. Install uv "
                        "(https://docs.astral.sh/uv/) and run `uv tool install browser-use`.")
@@ -385,9 +388,9 @@ def _native_screenshot_result(result: Dict[str, Any], path: str) -> Optional[Dic
 
         if not _should_use_native_vision_fast_path():
             return None
-        # History-reuse cap: this data URL bakes into the tool result and is
-        # re-sent every later turn — same policy as the vision_analyze /
-        # browser_vision native embeds (256 KB / 1568 px, JPEG quality ladder).
+        # History-reuse cap: this data URL bakes into the tool result and is re-sent
+        # every later turn — same policy as the vision_analyze / browser_vision native
+        # embeds (256 KB / 1568 px, JPEG quality ladder).
         data_url = _resize_image_for_vision(
             Path(path), mime_type="image/png", max_base64_bytes=_EMBED_TARGET_BYTES,
             max_dimension=_EMBED_MAX_DIMENSION, force_jpeg=True,
@@ -418,13 +421,9 @@ def _resolve_lightpanda_cdp(env: dict, task_id: Optional[str], session_name: str
     private to this session and the own-tab preamble is skipped."""
     try:
         from tools.browser_tool import _get_session_info, _using_lightpanda_engine
-    except Exception as e:  # pragma: no cover — stubbed browser_tool in tests
-        logger.debug("browser_tool lightpanda resolution unavailable: %s", e)
-        return None
-    try:
         if not _using_lightpanda_engine():
             return None
-    except Exception as e:
+    except Exception as e:  # stubbed browser_tool in tests / engine lookup failure
         logger.debug("browser engine lookup failed: %s", e)
         return None
     err = _export_session_cdp(
@@ -460,29 +459,22 @@ def _resolve_backend_cdp(env: dict, task_id: Optional[str], session_name: str =
         logger.debug("browser_tool backend resolution unavailable: %s", e)
         return None
 
-    try:
-        override = _get_cdp_override()
-    except Exception:
-        override = ""
+    override = _quiet(_get_cdp_override, "")
     if override:
         _set_cdp_env(env, override)
         return None
 
-    try:
-        provider = _get_cloud_provider()
-    except Exception as e:
-        logger.debug("Cloud provider lookup failed: %s", e)
-        provider = None
+    provider = _quiet(_get_cloud_provider, None, "Cloud provider lookup failed")
     if provider is None:
         return _resolve_lightpanda_cdp(env, task_id, session_name)
 
-    # Browser Use direct-API configs: the CLI talks to BU cloud natively
-    # (BU_AUTOSPAWN / auth login) — the legacy provider would create a second,
-    # redundant session. The Nous-gateway variant (use_gateway: true) DOES resolve
-    # through the provider: the gateway provisions the browser server-side and
-    # returns its CDP URL, giving subscribers CLI mode with no raw key.
+    # Browser Use direct-API configs: the CLI talks to BU cloud natively (BU_AUTOSPAWN /
+    # auth login) — the legacy provider would create a second, redundant session. The
+    # Nous-gateway variant (use_gateway: true) DOES resolve through the provider: the
+    # gateway provisions the browser server-side and returns its CDP URL, giving
+    # subscribers CLI mode with no raw key.
     provider_key = str(getattr(provider, "name", "") or "").strip().lower()
-    if provider_key == _BACKEND_KEY and not is_truthy_value(_read_browser_cfg().get("use_gateway"), default=False):
+    if provider_key == _BACKEND_KEY and not _use_gateway(_read_browser_cfg()):
         env[_PRIVATE_BROWSER_SENTINEL] = "1"  # named BU cloud browsers are exclusive to their daemon
         return None
 
@@ -501,11 +493,6 @@ def _resolve_backend_cdp(env: dict, task_id: Optional[str], session_name: str =
     return err
 
 
-def _real_profile_consented() -> bool:
-    """Whether the user opted in to real-profile local browsing (config read)."""
-    return _lazy_call("tools.browser_tool", "_use_real_profile", False, "real-profile consent lookup failed")
-
-
 def _resolve_real_profile_cdp(env: dict, force_local: bool) -> Optional[str]:
     """Point the harness at the user's real-profile copy-browser when consented.
 
@@ -527,19 +514,14 @@ def _resolve_real_profile_cdp(env: dict, force_local: bool) -> Optional[str]:
         logger.debug("real-profile backend resolution unavailable: %s", e)
         return None
 
-    try:
-        if _get_cdp_override_raw():
-            return None
-    except Exception:
-        pass
+    if _quiet(_get_cdp_override_raw, ""):
+        return None
 
     if not force_local:
-        # Only auto-upgrade genuinely-local attaches; any cloud path (provider or
-        # legacy BU cloud config) stays on its backend unless the model passes local=true.
-        try:
-            if _get_cloud_provider() is not None:
-                return None
-        except Exception:
+        # Only auto-upgrade genuinely-local attaches; any cloud path (provider, provider
+        # lookup failure, or legacy BU cloud config) stays on its backend unless the model
+        # passes local=true.
+        if _quiet(_get_cloud_provider, object()) is not None:
             return None
         if is_legacy_browser_use_cloud_config(_read_browser_cfg()):
             return None
@@ -576,14 +558,13 @@ def _windows_popen_kwargs() -> dict:
     """Hide the console the .cmd shim would flash on Windows (as browser_tool does)."""
     if os.name != "nt":
         return {}
-    try:
+    def _flags() -> dict:
         from hermes_cli._subprocess_compat import windows_hide_flags
         si = subprocess.STARTUPINFO()
         si.dwFlags |= subprocess.STARTF_USESHOWWINDOW
         return {"creationflags": windows_hide_flags(), "startupinfo": si}
-    except Exception as e:
-        logger.debug("Windows hide-flags unavailable: %s", e)
-        return {}
+
+    return _quiet(_flags, {}, "Windows hide-flags unavailable")
 
 
 def _clamp_timeout(timeout_s: Any) -> int:
@@ -746,21 +727,12 @@ _HELPERS_DIGEST = (
 # lives with the session, not in the process-wide TTL-cached check_fn.
 
 
-def _lightpanda_engine_in_use() -> bool:
-    return _lazy_call("tools.browser_tool", "lightpanda_engine_status", (False, ""),
-                      "lightpanda engine status unavailable")[0]
-
-
 def _description_header() -> str:
     """Header tailored to whether the active model can see images natively"""
     if _lightpanda_engine_in_use():  # no screenshots at all, whatever the model can see
         return _HEADER_BASE + _HEADER_TEXT_ONLY + _HEADER_LIGHTPANDA
-    try:
-        from tools.vision_tools import _should_use_native_vision_fast_path
-        if _should_use_native_vision_fast_path():
-            return _HEADER_BASE + _HEADER_VISION
-    except Exception:
-        pass
+    if _lazy_call("tools.vision_tools", "_should_use_native_vision_fast_path", False, ""):
+        return _HEADER_BASE + _HEADER_VISION
     return _HEADER_BASE + _HEADER_TEXT_ONLY