diff --git a/tests/tui_gateway/test_session_agent_cwd.py b/tests/tui_gateway/test_session_agent_cwd.py
new file mode 100644
index 0000000000..46695fae78
--- /dev/null
+++ b/tests/tui_gateway/test_session_agent_cwd.py
@@ -0,0 +1,184 @@
+"""Workspace changes reach new Codex threads without rebinding memory or prompts."""
+
+import socket
+import threading
+from types import SimpleNamespace
+from unittest.mock import MagicMock
+
+import pytest
+
+from agent import codex_runtime, runtime_cwd
+from agent.transports import codex_app_server_session
+from hermes_state import SessionDB
+from plugins.memory.honcho import HonchoMemoryProvider
+from plugins.memory.honcho.client import HonchoClientConfig
+from run_agent import AIAgent
+from tools import terminal_tool
+
+
+@pytest.fixture
+def workspace_runtime(monkeypatch, tmp_path):
+    # server imports start a background GitHub update check; disable it before import.
+    monkeypatch.setattr("hermes_cli.banner.prefetch_update_check", lambda: None)
+    from tui_gateway import server
+
+    old, new, other = (tmp_path / name for name in ("old-repo", "new-repo", "other-repo"))
+    for path in (old, new, other):
+        path.mkdir()
+    monkeypatch.chdir(other)
+    monkeypatch.setenv("TERMINAL_CWD", str(other))
+    monkeypatch.setattr(server, "_sessions", {})
+    monkeypatch.setattr(terminal_tool, "_task_env_overrides", {})
+    monkeypatch.setattr(server, "_load_cfg", lambda: {})
+    monkeypatch.setattr(server, "_emit", lambda *a, **k: None)
+    monkeypatch.setattr(server, "_session_info", lambda agent, session: {"cwd": session["cwd"]})
+    monkeypatch.setattr(server, "_persist_session_git_meta", lambda *a, **k: None)
+    monkeypatch.setattr("tools.terminal_tool_lifecycle.cleanup_vm", lambda *a: None)
+    monkeypatch.setattr("model_tools.get_tool_definitions", lambda *a, **k: [])
+    monkeypatch.setattr("model_tools.check_toolset_requirements", lambda *a, **k: {})
+    monkeypatch.setattr("agent.process_bootstrap.OpenAI", MagicMock())
+    monkeypatch.setattr("hermes_cli.config.load_config_readonly", lambda: {"memory": {"provider": "honcho"}})
+    # Real Honcho initialization/routing, but tools-only lazy mode never creates peers.
+    config = HonchoClientConfig(
+        enabled=True, api_key="test-key", session_strategy="per-directory",
+        recall_mode="tools", init_on_session_start=False,
+    )
+    monkeypatch.setattr(HonchoClientConfig, "from_global_config", lambda *a, **k: config)
+    providers, agents, starts, network_attempts = [], [], [], []
+
+    def load_provider(*a, **k):
+        provider = HonchoMemoryProvider()
+        providers.append(provider)
+        return provider
+
+    def blocked_connect(self, address):
+        network_attempts.append(address)
+        raise AssertionError(f"unexpected network access: {address}")
+
+    class CodexClient:
+        def __init__(self, **kwargs):
+            pass
+
+        def initialize(self, **kwargs):
+            pass
+
+        def request(self, method, params, **kwargs):
+            assert method == "thread/start"
+            starts.append(params["cwd"])
+            return {"thread": {"id": "test-thread"}}
+
+        def close(self):
+            pass
+
+    monkeypatch.setattr("plugins.memory.load_memory_provider", load_provider)
+    monkeypatch.setattr(socket.socket, "connect", blocked_connect)
+    monkeypatch.setattr(codex_app_server_session, "CodexAppServerClient", CodexClient)
+    db = SessionDB(tmp_path / "state.db")
+    monkeypatch.setattr(server, "_get_db", lambda: db)
+
+    def build(cwd, key="conversation"):
+        agent = AIAgent(
+            model="test-model", api_key="test-key", base_url="https://example.invalid/v1",
+            quiet_mode=True, skip_context_files=True, skip_background_review=True,
+            save_trajectories=False, platform="gui", session_id=key, session_db=db,
+            cwd=cwd,
+        )
+        agents.append(agent)
+        agent._cached_system_prompt = f"Stable prompt for {key}"
+        return agent
+
+    def move(action, session, cwd):
+        if action == "project-tool":
+            server._apply_project_workspace(session["session_key"], str(cwd))
+        else:
+            response = server._methods[action]("move", {
+                "session_id": "ui-session", "session_key": session["session_key"], "cwd": str(cwd),
+            })
+            assert "error" not in response, response
+        assert session["cwd"] == str(cwd)
+
+    try:
+        yield SimpleNamespace(old=old, new=new, other=other, build=build, move=move,
+                              providers=providers, starts=starts, server=server)
+    finally:
+        for agent in agents:
+            codex_runtime._close_codex_session(agent)
+            agent.close()
+        db.close()
+        assert not network_attempts
+
+
+@pytest.mark.parametrize("action", ["project-tool", "session.cwd.set", "session.workspace.move"])
+@pytest.mark.parametrize("restart", [False, True], ids=["first-thread", "restarted-thread"])
+def test_explicit_workspace_moves_reach_new_codex_threads(workspace_runtime, action, restart):
+    runtime = workspace_runtime
+    server = runtime.server
+    agent = runtime.build(str(runtime.old))
+    neighbor = runtime.build(str(runtime.other), key="neighbor")
+    session = {"agent": agent, "session_key": agent.session_id, "cwd": str(runtime.old), "source": "desktop"}
+    server._sessions["ui-session"] = session
+    provider = runtime.providers[0]
+    prompt, memory_key = agent._cached_system_prompt, provider._session_key
+    assert memory_key == runtime.old.name
+    existing = None
+    if restart:
+        codex_runtime._ensure_codex_session(agent)
+        agent._codex_session.ensure_started()
+        assert runtime.starts[-1] == str(runtime.old)
+        existing = agent._codex_session
+    runtime.move(action, session, runtime.new)
+    if restart:
+        # Moving the workspace must not replace an already-running Codex thread.
+        codex_runtime._ensure_codex_session(agent)
+        assert agent._codex_session is existing
+        codex_runtime._close_codex_session(agent)
+    tokens = server._set_session_context(agent.session_id)
+    try:
+        assert runtime_cwd.resolve_agent_cwd() == runtime.new
+        codex_runtime._ensure_codex_session(agent)
+        agent._codex_session.ensure_started()
+        assert runtime.starts[-1] == str(runtime.new)
+    finally:
+        server._clear_session_context(tokens)
+    assert terminal_tool._task_env_overrides[agent.session_id]["cwd"] == str(runtime.new)
+    assert neighbor.session_cwd == str(runtime.other)
+    assert runtime_cwd.resolve_agent_cwd() == runtime.other
+    assert provider._session_key == memory_key
+    assert provider._lazy_init_kwargs["cwd"] == str(runtime.old)
+    assert agent._cached_system_prompt == prompt
+
+
+def test_workspace_move_during_deferred_build_reaches_first_codex_thread(workspace_runtime, monkeypatch):
+    runtime = workspace_runtime
+    server = runtime.server
+    constructed, release, ready = threading.Event(), threading.Event(), threading.Event()
+    session = {"agent": None, "agent_ready": ready, "session_key": "deferred",
+               "cwd": str(runtime.old), "source": "desktop"}
+    server._sessions["ui-session"] = session
+
+    def make_agent(sid, key, **kwargs):
+        agent = runtime.build(kwargs["cwd_override"], key)
+        constructed.set()
+        assert release.wait(timeout=15), "test did not release deferred build"
+        return agent
+
+    monkeypatch.setattr(server, "_make_agent", make_agent)
+    monkeypatch.setattr("tui_gateway.entry.ensure_mcp_discovery_started", lambda: None)
+    monkeypatch.setattr(server, "_wire_session_agent", lambda *a: False)
+    monkeypatch.setattr(server, "_announce_built_agent", lambda *a: None)
+    monkeypatch.setattr(server, "_config_model_target", lambda: ("", ""))
+    server._start_agent_build("ui-session", session)
+    try:
+        assert constructed.wait(timeout=15), "agent was not constructed"
+        runtime.move("session.workspace.move", session, runtime.new)
+    finally:
+        release.set()
+        assert ready.wait(timeout=15), "deferred build did not finish"
+    assert not session.get("agent_error")
+    agent = session["agent"]
+    codex_runtime._ensure_codex_session(agent)
+    agent._codex_session.ensure_started()
+    assert runtime.starts[-1] == str(runtime.new)
+    assert runtime.providers[0]._session_key == runtime.old.name
+    assert runtime.providers[0]._lazy_init_kwargs["cwd"] == str(runtime.old)
+    assert agent._cached_system_prompt == f"Stable prompt for {agent.session_id}"
diff --git a/tui_gateway/session_workdir.py b/tui_gateway/session_workdir.py
index fa0927656c..dd3032d00f 100644
--- a/tui_gateway/session_workdir.py
+++ b/tui_gateway/session_workdir.py
@@ -195,6 +195,10 @@ def _session_source(session: dict | None) -> str:
 def _register_session_cwd(session: dict | None) -> None:
     if not session:
         return
+    # Workspace moves must reach lazy/restarted runtimes, not just terminal tools.
+    # Do not reinitialize memory providers or invalidate the cached system prompt.
+    if (agent := session.get("agent")) is not None:
+        agent.session_cwd = session.get("cwd") or None
     with contextlib.suppress(Exception):
         from tools.terminal_tool import register_task_env_overrides
         cwd, cwd_source = _terminal_task_cwd_with_source(session)
diff --git a/website/docs/developer-guide/memory-provider-plugin.md b/website/docs/developer-guide/memory-provider-plugin.md
index a006eca911..8ddfc64796 100644
--- a/website/docs/developer-guide/memory-provider-plugin.md
+++ b/website/docs/developer-guide/memory-provider-plugin.md
@@ -123,6 +123,15 @@ context, then scoped `terminal.cwd` (carried internally as `TERMINAL_CWD`), then
 the launch directory. Construction-time workspace metadata does not require
 changing the process cwd or rebuilding an existing conversation's system prompt.
 
+Desktop/TUI workspace changes synchronize the live agent's `session_cwd` through
+`tui_gateway/session_workdir.py::_register_session_cwd`, including when a deferred
+agent is attached after a workspace move. This lets a first or restarted Codex
+app-server session use the current workspace instead of its construction-time
+cwd. It does not move an already-running Codex thread, reinitialize memory
+providers, change an existing Honcho session identity, or invalidate the cached
+system prompt. Provider initialization still receives the construction-time
+workspace; absent or empty cwd remains unpinned.
+
 ## Required Methods
 
 ### Core Lifecycle