diff --git a/agent/memory_manager.py b/agent/memory_manager.py
index 850a9bb410..d7f9caa632 100644
--- a/agent/memory_manager.py
+++ b/agent/memory_manager.py
@@ -16,7 +16,7 @@ from concurrent.futures import Future, ThreadPoolExecutor, wait
 from functools import partial
 from typing import Any, Callable, Dict, List, Optional
 
-from agent.memory_provider import MemoryProvider, PRE_COMPRESS_CHECKPOINT_API_VERSION
+from agent.memory_provider import MemoryProvider, PRE_COMPRESS_CHECKPOINT_API_VERSION, ctx_bound, spawn_context_thread
 from agent.skill_commands import extract_user_instruction_from_skill_message
 from tools.hook_output_spill import get_spill_config, spill_if_oversized
 from tools.registry import tool_error
@@ -59,12 +59,6 @@ def _accepts_require_checkpoint(fn: Callable[..., Any]) -> bool:
     return _has_var_kwargs(params) or kind in (inspect.Parameter.KEYWORD_ONLY, inspect.Parameter.POSITIONAL_OR_KEYWORD)
 
 
-def _ctx_bound(fn: Callable[[], Any]) -> Callable[[], Any]:
-    """Bind ``fn`` to the CALLER's contextvars for another thread: profile isolation is a
-    ContextVar-scoped HERMES_HOME override, and an unbound worker would silently use the default profile."""
-    return partial(contextvars.copy_context().run, fn)
-
-
 # -- Tool-schema plumbing -----------------------------------------------------
 
 def normalize_tool_schema(schema: Any) -> Optional[Dict[str, Any]]:
@@ -421,7 +415,7 @@ class MemoryManager:
             except Exception as exc:  # pragma: no cover - re-raised by caller
                 result_box["error"] = exc
 
-        thread = threading.Thread(target=_ctx_bound(_run), daemon=True, name=f"memory-prefetch-{provider.name}")
+        thread = spawn_context_thread(_run, name=f"memory-prefetch-{provider.name}")
         with self._external_prefetch_lock:
             existing = self._external_prefetch_threads.get(provider.name)
             if existing is not None and existing.is_alive():
@@ -511,9 +505,9 @@ class MemoryManager:
 
     def _submit_background(self, fn, *, kind: str = "write") -> None:
         """Queue ``fn`` on the serialized worker (created lazily; None once shutting down) and track its
-        durability class. Runs under the caller's contextvars (``_ctx_bound``). If the executor is
+        durability class. Runs under the caller's contextvars (``ctx_bound``). If the executor is
         unavailable outside shutdown, run inline — the historical fail-safe."""
-        fn = _ctx_bound(fn)
+        fn = ctx_bound(fn)
         executor = None if self._shutting_down else self._sync_executor
         if executor is None and not self._shutting_down:
             with self._sync_executor_lock:
diff --git a/agent/memory_provider.py b/agent/memory_provider.py
index 9d698ada7a..b5a9d2edc5 100644
--- a/agent/memory_provider.py
+++ b/agent/memory_provider.py
@@ -7,14 +7,31 @@ prefetch / sync_turn per turn -> tool dispatch -> shutdown, plus optional ``on_*
 
 from __future__ import annotations
 
+import contextvars
 import logging
 import re
+import threading
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
-from typing import Any, Dict, List, Optional
+from typing import Any, Callable, Dict, List, Optional
 
 logger = logging.getLogger(__name__)
 
+
+def ctx_bound(fn: Callable[..., Any]) -> Callable[..., Any]:
+    """Bind ``fn`` to the CALLER's contextvars for another thread/executor. Profile isolation
+    is a ContextVar-scoped HERMES_HOME override plus the per-turn secret scope; a worker started
+    with an empty context silently lands on the default profile (or fails closed on secrets)."""
+    ctx = contextvars.copy_context()
+    return lambda *args, **kwargs: ctx.run(fn, *args, **kwargs)
+
+
+def spawn_context_thread(target: Callable[..., Any], *, name: str, daemon: bool = True,
+                         args: tuple = ()) -> threading.Thread:
+    """Unstarted thread running *target* under the spawner's contextvars (see :func:`ctx_bound`).
+    Every memory-provider background job (prefetch, sync, writer loops) must go through this."""
+    return threading.Thread(target=ctx_bound(target), args=args, name=name, daemon=daemon)
+
 # v1 = best-effort on_pre_compress() with the raw message list; v2 = opt-in fail-closed
 # checkpoint (normalized evidence handoff + strict-mode failure propagation).
 PRE_COMPRESS_CHECKPOINT_API_VERSION = 2
diff --git a/plugins/memory/byterover/__init__.py b/plugins/memory/byterover/__init__.py
index 6d81225bf5..42c2684b48 100644
--- a/plugins/memory/byterover/__init__.py
+++ b/plugins/memory/byterover/__init__.py
@@ -17,7 +17,7 @@ import threading
 from pathlib import Path
 from typing import Any, Dict, List, Optional
 
-from agent.memory_provider import MemoryProvider
+from agent.memory_provider import MemoryProvider, spawn_context_thread
 from tools.registry import tool_error
 
 logger = logging.getLogger(__name__)
@@ -171,7 +171,7 @@ class ByteRoverMemoryProvider(MemoryProvider):
             except Exception as e:
                 logger.debug("ByteRover %s failed: %s", what, e)
 
-        t = threading.Thread(target=_work, daemon=True, name=name)
+        t = spawn_context_thread(_work, name=name)
         t.start()
         return t
 
diff --git a/plugins/memory/hindsight/__init__.py b/plugins/memory/hindsight/__init__.py
index 25e663e761..1cc6d708bc 100644
--- a/plugins/memory/hindsight/__init__.py
+++ b/plugins/memory/hindsight/__init__.py
@@ -13,7 +13,6 @@ from __future__ import annotations
 import asyncio
 import atexit
 import contextlib
-import contextvars
 import json
 import logging
 import os
@@ -25,12 +24,13 @@ from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any, Callable, Dict, List, Optional
 
-from agent.memory_provider import MemoryProvider, RecallStatus
+from agent.memory_provider import MemoryProvider, RecallStatus, spawn_context_thread
 from agent.secret_scope import get_secret
 from hermes_cli.config import cfg_get
 from hermes_constants import get_hermes_home
 from hermes_time import now as _hermes_now
 from tools.registry import tool_error
+from utils import read_json_or_empty
 
 from .embedded import (
     _RETRIABLE_CONNECTION_MARKERS, _build_embedded_profile_env,
@@ -185,14 +185,6 @@ def _run_sync(coro, timeout: float = _DEFAULT_TIMEOUT):
     return future.result(timeout=timeout)
 
 
-def _context_thread(target, name: str) -> threading.Thread:
-    """Daemon thread running *target* in a snapshot of the spawner's contextvars.
-    Threads start with an EMPTY Context; under multiplex_profiles get_secret fails
-    closed without the profile's secret scope + HERMES_HOME override. (The shared
-    loop needs no wrap: run_coroutine_threadsafe inherits the submitter's context.)"""
-    return threading.Thread(target=contextvars.copy_context().run, args=(target,), daemon=True, name=name)
-
-
 RETAIN_SCHEMA = {
     "name": "hindsight_retain",
     "description": (
@@ -244,8 +236,7 @@ def _load_config() -> dict:
     (legacy, shared), else environment variables."""
     for path in (get_hermes_home() / "hindsight" / "config.json", Path.home() / ".hindsight" / "config.json"):
         if path.exists():
-            with contextlib.suppress(Exception):
-                return json.loads(path.read_text(encoding="utf-8"))
+            return read_json_or_empty(path)
     # Mode, bank (the data partition), endpoint and retain shaping are per-profile .env values like
     # the key beside them: read through the secret scope so a multiplexed secondary never inherits
     # the default profile's bank/mode. Tuning knobs (timeouts, budget) stay process-global.
@@ -389,13 +380,7 @@ class HindsightMemoryProvider(MemoryProvider):
         """Merge *values* into $HERMES_HOME/hindsight/config.json."""
         from utils import atomic_json_write
         config_path = Path(hermes_home) / "hindsight" / "config.json"
-        config_path.parent.mkdir(parents=True, exist_ok=True)
-        existing = {}
-        if config_path.exists():
-            with contextlib.suppress(Exception):
-                existing = json.loads(config_path.read_text(encoding="utf-8"))
-        existing.update(values)
-        atomic_json_write(config_path, existing, mode=0o600)
+        atomic_json_write(config_path, {**read_json_or_empty(config_path), **values}, mode=0o600)
 
     def post_setup(self, hermes_home: str, config: dict) -> None:
         """Custom setup wizard — installs only the deps needed for the selected mode."""
@@ -519,7 +504,7 @@ class HindsightMemoryProvider(MemoryProvider):
             return
         # A previous writer may have exited after shutdown(); allow the fresh one to drain.
         self._shutting_down.clear()
-        thread = _context_thread(self._writer_loop, "hindsight-writer")
+        thread = spawn_context_thread(self._writer_loop, name="hindsight-writer")
         self._writer_thread = self._sync_thread = thread
         thread.start()
 
@@ -805,7 +790,7 @@ class HindsightMemoryProvider(MemoryProvider):
                 print(f"  ⚠ {msg}", file=sys.stderr, flush=True)
             self._mode = "disabled"
             return
-        _context_thread(self._daemon_start_worker, "hindsight-daemon-start").start()
+        spawn_context_thread(self._daemon_start_worker, name="hindsight-daemon-start").start()
 
     def _daemon_start_worker(self) -> None:
         import traceback
@@ -951,7 +936,7 @@ class HindsightMemoryProvider(MemoryProvider):
                 with self._prefetch_lock:
                     self._prefetch_result, self._prefetch_count = text, count
 
-        self._prefetch_thread = _context_thread(_run, "hindsight-prefetch")
+        self._prefetch_thread = spawn_context_thread(_run, name="hindsight-prefetch")
         self._prefetch_thread.start()
 
     # -- retain ------------------------------------------------------------------
diff --git a/plugins/memory/holographic/__init__.py b/plugins/memory/holographic/__init__.py
index 8ff1d0ce9a..aede5a1323 100644
--- a/plugins/memory/holographic/__init__.py
+++ b/plugins/memory/holographic/__init__.py
@@ -113,16 +113,10 @@ class HolographicMemoryProvider(MemoryProvider):
 
     def save_config(self, values, hermes_home):
         """Write config to config.yaml under plugins.hermes-memory-store."""
-        config_path = Path(hermes_home) / "config.yaml"
-        try:
-            import yaml
-            from hermes_cli.config import read_user_config_raw  # raw read: merged defaults must not be persisted
-            existing = read_user_config_raw(config_path)
-            existing.setdefault("plugins", {})["hermes-memory-store"] = values
-            with open(config_path, "w", encoding="utf-8") as f:
-                yaml.dump(existing, f, default_flow_style=False)
-        except Exception:
-            pass
+        # The canonical writer: config lock, managed-mode refusal, default stripping, atomic replace.
+        # ``merge_existing`` keeps every other section; *hermes_home* is the active profile already.
+        from hermes_cli.config import save_config
+        save_config({"plugins": {"hermes-memory-store": dict(values)}}, merge_existing=True)
 
     def get_config_schema(self):
         from hermes_constants import display_hermes_home
diff --git a/plugins/memory/honcho/__init__.py b/plugins/memory/honcho/__init__.py
index 834cc0e48e..261018b7c3 100644
--- a/plugins/memory/honcho/__init__.py
+++ b/plugins/memory/honcho/__init__.py
@@ -17,9 +17,9 @@ import time
 from typing import Any, Callable, Dict, List, Optional
 
 from agent.memory_manager import sanitize_context
-from agent.memory_provider import MemoryProvider, is_trivial_prompt
+from agent.memory_provider import MemoryProvider, is_trivial_prompt, spawn_context_thread
 from agent.turn_author import a2a_key
-from plugins.memory.honcho.client import HonchoClientConfig, resolve_config_path, spawn_context_thread
+from plugins.memory.honcho.client import HonchoClientConfig, resolve_config_path
 from plugins.memory.honcho.dialectic import DialecticMixin
 from plugins.memory.honcho.session_peers import assistant_peer_id_for, sanitize_peer_id
 from plugins.memory.honcho.tool_schemas import ALL_TOOL_SCHEMAS
@@ -168,14 +168,9 @@ class HonchoMemoryProvider(DialecticMixin, MemoryProvider):
     def save_config(self, values, hermes_home):
         """Merge ``values`` into $HERMES_HOME/honcho.json (Honcho SDK native format)."""
         from pathlib import Path
-        from utils import atomic_json_write
-        from plugins.memory.honcho.client import _read_config
+        from utils import atomic_json_write, read_json_or_empty
         config_path = Path(hermes_home) / "honcho.json"
-        try:
-            existing = _read_config(config_path)
-        except Exception:
-            existing = {}
-        atomic_json_write(config_path, {**existing, **values}, mode=0o600)
+        atomic_json_write(config_path, {**read_json_or_empty(config_path), **values}, mode=0o600)
 
     def get_config_schema(self):
         return [
diff --git a/plugins/memory/honcho/cli.py b/plugins/memory/honcho/cli.py
index eda74badd7..722390f83e 100644
--- a/plugins/memory/honcho/cli.py
+++ b/plugins/memory/honcho/cli.py
@@ -10,6 +10,7 @@ from pathlib import Path
 from hermes_constants import get_hermes_home
 from plugins.memory.honcho.client import _first_parsed, _host_block, profile_host_key, resolve_active_host, resolve_config_path, HOST
 from hermes_cli.config import cfg_get
+from utils import read_json_or_empty
 
 RULE = "─" * 40
 REASONING_LEVELS = ("minimal", "low", "medium", "high", "max")
@@ -66,10 +67,7 @@ def _local_config_path() -> Path:
 
 
 def _read_config() -> dict:
-    try:
-        return json.loads(_config_path().read_text(encoding="utf-8"))
-    except Exception:
-        return {}
+    return read_json_or_empty(_config_path())
 
 
 def _write_config(cfg: dict, path: Path | None = None) -> None:
diff --git a/plugins/memory/honcho/client.py b/plugins/memory/honcho/client.py
index 035173688a..2b18e870aa 100644
--- a/plugins/memory/honcho/client.py
+++ b/plugins/memory/honcho/client.py
@@ -17,7 +17,6 @@ import os
 # replacing the single process-wide slot that pinned the first profile's workspace and bearer for every
 # later profile in multi-profile processes (#69123 multiplexed gateway, #74065 dashboard). The legacy names
 # above are retained only for reset bookkeeping.
-import threading as _threading
 from dataclasses import dataclass, field
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Callable
@@ -507,16 +506,6 @@ class HonchoClientConfig:
         return self.workspace_id
 
 
-def spawn_context_thread(target, *, name: str, daemon: bool = True, args: tuple = ()) -> "_threading.Thread":
-    """Thread that inherits the caller's contextvars: profile isolation is a ContextVar
-    (set_hermes_home_override) and a plain Thread starts EMPTY, so ambient resolution on it
-    would silently land on the default profile."""
-    import contextvars
-
-    ctx = contextvars.copy_context()
-    return _threading.Thread(target=lambda: ctx.run(target, *args), name=name, daemon=daemon)
-
-
 def get_honcho_client(config: HonchoClientConfig | None = None) -> Honcho:
     """Get or create the Honcho client for this config's identity. Clients are cached PER
     IDENTITY (host, workspace, provenance paths, credential fingerprint, timeout) so
diff --git a/plugins/memory/honcho/dialectic.py b/plugins/memory/honcho/dialectic.py
index eaaca19fd1..1a49353339 100644
--- a/plugins/memory/honcho/dialectic.py
+++ b/plugins/memory/honcho/dialectic.py
@@ -7,7 +7,7 @@ import re
 import threading
 import time
 
-from plugins.memory.honcho.client import spawn_context_thread
+from agent.memory_provider import spawn_context_thread
 
 logger = logging.getLogger("plugins.memory.honcho")
 
diff --git a/plugins/memory/honcho/oauth.py b/plugins/memory/honcho/oauth.py
index 7de658ca34..b78227a340 100644
--- a/plugins/memory/honcho/oauth.py
+++ b/plugins/memory/honcho/oauth.py
@@ -21,6 +21,7 @@ from pathlib import Path
 from typing import Any
 
 from agent.redact import redact_sensitive_text, register_redaction_patterns
+from utils import read_json_or_empty
 
 logger = logging.getLogger(__name__)
 
@@ -106,15 +107,9 @@ def _mark_grant_dead(key: tuple[str, str], cred: OAuthCredential) -> None:
     _dead_grants[key] = hashlib.sha256(cred.refresh_token.encode("utf-8")).hexdigest()
     _reauth_check_cache.pop(key, None)  # verdict changed without a config rewrite
 
-def _read_config(path: Path) -> dict[str, Any]:
-    try:
-        return json.loads(path.read_text(encoding="utf-8"))
-    except (OSError, json.JSONDecodeError):
-        return {}
-
 def _load_cred(path: Path, host: str, raw: dict[str, Any] | None = None) -> OAuthCredential | None:
     """Credential from ``host``'s block in ``raw`` (or the file at ``path``)."""
-    source = raw if raw is not None else _read_config(path)
+    source = raw if raw is not None else read_json_or_empty(path)
     return OAuthCredential.from_host_block((source.get("hosts") or {}).get(host) or {})
 
 def reauth_required(path: Path, host: str) -> bool:
@@ -284,7 +279,7 @@ def _persist_credential(path: Path, host: str, cred: OAuthCredential, raw: dict[
     the file's current content), leaving the rest intact; marks the grant live."""
     from utils import atomic_json_write
 
-    raw = _read_config(path) if raw is None else raw
+    raw = read_json_or_empty(path) if raw is None else raw
     block = raw.setdefault("hosts", {}).setdefault(host, {})
     block["apiKey"], block["oauth"] = cred.access_token, cred.oauth_block()
     atomic_json_write(path, raw, mode=0o600)
@@ -360,7 +355,7 @@ def install_grant(
     ``apiKey`` and ``oauth`` block. ``apply_config=False`` stores tokens only."""
     now = time.time() if now is None else now
     cred = OAuthCredential.from_token_response(grant, now=now, client_id=client_id, token_endpoint=token_endpoint)
-    raw = _read_config(path)
+    raw = read_json_or_empty(path)
     granted_config = grant.get("config")
     if isinstance(granted_config, dict):
         cred.consent_peer_name = granted_config.get("peerName")
diff --git a/plugins/memory/honcho/recall_sync.py b/plugins/memory/honcho/recall_sync.py
index 9c25d1a1e6..6c93f51b8d 100644
--- a/plugins/memory/honcho/recall_sync.py
+++ b/plugins/memory/honcho/recall_sync.py
@@ -7,7 +7,7 @@ import math
 import threading
 import time
 
-from plugins.memory.honcho.client import spawn_context_thread
+from agent.memory_provider import spawn_context_thread
 
 logger = logging.getLogger("plugins.memory.honcho")
 
diff --git a/plugins/memory/honcho/session.py b/plugins/memory/honcho/session.py
index 3c04e19b45..2c8b6e6280 100644
--- a/plugins/memory/honcho/session.py
+++ b/plugins/memory/honcho/session.py
@@ -10,7 +10,8 @@ from dataclasses import dataclass, field
 from datetime import datetime
 from typing import Any, TYPE_CHECKING
 
-from plugins.memory.honcho.client import get_honcho_client, spawn_context_thread
+from agent.memory_provider import spawn_context_thread
+from plugins.memory.honcho.client import get_honcho_client
 from plugins.memory.honcho.session_auth import HonchoAuthError, SessionAuthMixin
 from plugins.memory.honcho.session_context import SessionContextMixin
 from plugins.memory.honcho.session_migration import SessionMigrationMixin
diff --git a/plugins/memory/mem0/__init__.py b/plugins/memory/mem0/__init__.py
index d873167e0d..f5ec6770f5 100644
--- a/plugins/memory/mem0/__init__.py
+++ b/plugins/memory/mem0/__init__.py
@@ -18,9 +18,10 @@ from contextlib import suppress
 from pathlib import Path
 from typing import Any, Dict, List
 
-from agent.memory_provider import MemoryProvider
+from agent.memory_provider import MemoryProvider, spawn_context_thread
 from agent.secret_scope import UnscopedSecretError, get_secret
 from tools.registry import tool_error
+from utils import atomic_json_write, read_json_or_empty
 
 logger = logging.getLogger(__name__)
 
@@ -72,14 +73,6 @@ def _is_client_error(exc: Exception) -> bool:
     return type(exc).__name__ in _CLIENT_ERROR_TYPES or any(s in err_str for s in ("404", "not found", "valid uuid"))
 
 
-def _read_mem0_json(config_path: Path) -> dict:
-    """Best-effort read of mem0.json; missing/corrupt file -> {}."""
-    if config_path.exists():
-        with suppress(Exception):
-            return json.loads(config_path.read_text(encoding="utf-8"))
-    return {}
-
-
 def _scoped_env(name: str) -> str:
     """Profile-scoped read of a non-secret mem0 setting; no scope under multiplex = unset (never
     ``os.environ``). Only the API key may fail closed — OSS mode has none to read (#99121)."""
@@ -100,7 +93,7 @@ def _load_config() -> dict:
               "agent_id": _scoped_env("MEM0_AGENT_ID") or "hermes", "oss": {}}
     if user_id := _scoped_env("MEM0_USER_ID"):  # only when explicitly configured, so initialize() can fall back to the gateway-native id
         config["user_id"] = user_id
-    file_cfg = _read_mem0_json(get_hermes_home() / "mem0.json")
+    file_cfg = read_json_or_empty(get_hermes_home() / "mem0.json")
     config.update({k: v for k, v in file_cfg.items() if v is not None and v != ""})
     # MEM0_API_KEY authenticates the Platform and self-hosted HTTP backends; pure OSS mode builds its
     # backend from the local ``oss`` config and has no platform credential to resolve. Decide after
@@ -161,9 +154,8 @@ class Mem0MemoryProvider(MemoryProvider):
 
     def save_config(self, values, hermes_home):
         """Merge-write config to $HERMES_HOME/mem0.json."""
-        from utils import atomic_json_write
         config_path = Path(hermes_home) / "mem0.json"
-        atomic_json_write(config_path, {**_read_mem0_json(config_path), **values}, mode=0o600)
+        atomic_json_write(config_path, {**read_json_or_empty(config_path), **values}, mode=0o600)
 
     def get_config_schema(self):
         api_key_required = _load_config().get("mode", "platform") != "oss"
@@ -299,7 +291,7 @@ class Mem0MemoryProvider(MemoryProvider):
             if self._prefetch_query == query and (self._prefetch_done or (self._prefetch_thread and self._prefetch_thread.is_alive())):
                 return
             self._prefetch_query, self._prefetch_result, self._prefetch_done = query, "", False
-            self._prefetch_thread = t = threading.Thread(target=_run, daemon=True, name="mem0-prefetch")
+            self._prefetch_thread = t = spawn_context_thread(_run, name="mem0-prefetch")
         t.start()
 
     def prefetch(self, query: str, *, session_id: str = "") -> str:
@@ -332,7 +324,7 @@ class Mem0MemoryProvider(MemoryProvider):
                 prev.join(timeout=5.0)
                 if prev.is_alive():  # still busy after the wait: skip to avoid duplicate ingestion
                     return
-            self._sync_thread = threading.Thread(target=_sync, daemon=True, name="mem0-sync")
+            self._sync_thread = spawn_context_thread(_sync, name="mem0-sync")
             self._sync_thread.start()
 
     def get_tool_schemas(self) -> List[Dict[str, Any]]:
diff --git a/plugins/memory/mem0/_setup.py b/plugins/memory/mem0/_setup.py
index 60bcbfc3ce..9db123667c 100644
--- a/plugins/memory/mem0/_setup.py
+++ b/plugins/memory/mem0/_setup.py
@@ -169,8 +169,8 @@ def _persist_provider_config(hermes_home: str, config: dict, provider_config: di
 
 def _setup_platform(hermes_home: str, config: dict, flags: dict[str, str]) -> None:
     """Platform mode setup — prompts for API key (secret -> .env), user/agent ids and rerank (-> mem0.json)."""
-    from . import _read_mem0_json
-    provider_config = _read_mem0_json(Path(hermes_home) / "mem0.json")
+    from utils import read_json_or_empty
+    provider_config = read_json_or_empty(Path(hermes_home) / "mem0.json")
     print("\n  Configuring mem0:\n")
     env_writes = _api_key_writes(flags, "Mem0 Platform API key", url="https://app.mem0.ai")
     for key, desc, default in (("user_id", "User identifier", "hermes-user"), ("agent_id", "Agent identifier", "hermes")):
@@ -205,8 +205,8 @@ def _check_selfhosted_server(host: str) -> None:
 
 def _setup_selfhosted(hermes_home: str, config: dict, flags: dict[str, str]) -> None:
     """Self-hosted mode — point at an existing Mem0 server: URL -> mem0.json, key -> .env (MEM0_API_KEY)."""
-    from . import _read_mem0_json
-    provider_config = _read_mem0_json(Path(hermes_home) / "mem0.json")
+    from utils import read_json_or_empty
+    provider_config = read_json_or_empty(Path(hermes_home) / "mem0.json")
     print("\n  Configuring mem0 (self-hosted server):\n")
     host = flags.get("host") or _prompt("Mem0 server URL (e.g. http://localhost:8888)", default=provider_config.get("host") or None)
     if not host:
@@ -238,11 +238,11 @@ def _print_oss_summary(oss_config: dict, env_writes: dict, dry_run: bool = False
 
 def _finish_oss(hermes_home: str, config: dict, oss_config: dict, env_writes: dict[str, str], user_id: str, agent_id: str, pgvector_config: dict | None = None) -> None:
     """Shared OSS tail: write secrets + mem0.json, install deps, activate, check, summarize."""
-    from . import _read_mem0_json
+    from utils import read_json_or_empty
     if env_writes:
         _write_env(Path(hermes_home) / ".env", env_writes)
     config_path = Path(hermes_home) / "mem0.json"  # merge-write, plain text (platform path uses save_config's 0600 atomic write)
-    config_path.write_text(json.dumps({**_read_mem0_json(config_path), "mode": "oss", "user_id": user_id, "agent_id": agent_id, "oss": oss_config}, indent=2) + "\n", encoding="utf-8")
+    config_path.write_text(json.dumps({**read_json_or_empty(config_path), "mode": "oss", "user_id": user_id, "agent_id": agent_id, "oss": oss_config}, indent=2) + "\n", encoding="utf-8")
     _install_provider_deps(oss_config["llm"]["provider"], oss_config["embedder"]["provider"], oss_config["vector_store"]["provider"])
     if pgvector_config:
         _ensure_pgvector_extension(pgvector_config)
diff --git a/plugins/memory/openviking/__init__.py b/plugins/memory/openviking/__init__.py
index f29341be05..97a3c255d6 100644
--- a/plugins/memory/openviking/__init__.py
+++ b/plugins/memory/openviking/__init__.py
@@ -35,10 +35,11 @@ from urllib.parse import quote, unquote, urlparse
 from urllib.request import url2pathname
 
 from agent.message_content import flatten_message_text
-from agent.memory_provider import MemoryProvider
+from agent.memory_provider import MemoryProvider, spawn_context_thread
 from agent.secret_scope import get_secret
 from agent.skill_commands import extract_user_instruction_from_skill_message
 from hermes_cli import __version__ as _HERMES_VERSION
+from hermes_constants import get_hermes_home
 from tools.registry import tool_error
 from utils import atomic_json_write, env_var_enabled
 
@@ -904,15 +905,6 @@ def _local_openviking_bind(endpoint: str) -> tuple[str, int]:
     return parsed.hostname or "127.0.0.1", parsed.port or 1933
 
 
-def _hermes_home_path() -> Path:
-    try:
-        from hermes_constants import get_hermes_home
-        return get_hermes_home()
-    except Exception:
-        env_home = os.environ.get("HERMES_HOME")
-        return Path(env_home).expanduser() if env_home else Path.home() / ".hermes"
-
-
 def _local_openviking_port_is_open(host: str, port: int) -> bool:
     """Pre-spawn guard: a successful connect proves a listener owns the port (so a
     second openviking-server would lose the data-dir lock); says nothing about health."""
@@ -976,7 +968,7 @@ def _start_local_openviking_server(endpoint: str) -> tuple[str, str]:
     server_cmd = shutil.which("openviking-server")
     if not server_cmd:
         return _LOCAL_SERVER_FAILED, "openviking-server was not found on PATH. Start it manually, then retry."
-    log_path = _hermes_home_path() / _OPENVIKING_SERVER_LOG_RELATIVE_PATH
+    log_path = get_hermes_home() / _OPENVIKING_SERVER_LOG_RELATIVE_PATH
     try:
         log_path.parent.mkdir(parents=True, exist_ok=True)
         # Strip PYTHONPATH: the Desktop backend puts the Hermes venv on it, which
@@ -1316,9 +1308,9 @@ class OpenVikingMemoryProvider(MemoryProvider):
         # Caller holds _runtime_start_lock and reserved ownership via _runtime_start_pending.
         if self._runtime_start_thread and self._runtime_start_thread.is_alive():
             return
-        self._runtime_start_thread = threading.Thread(
-            target=self._finish_runtime_openviking_start, daemon=True, name="openviking-runtime-start",
-            kwargs={"endpoint": endpoint, "status_callback": status_callback, "warning_callback": warning_callback})
+        self._runtime_start_thread = spawn_context_thread(
+            lambda: self._finish_runtime_openviking_start(endpoint=endpoint, status_callback=status_callback, warning_callback=warning_callback),
+            name="openviking-runtime-start")
         self._runtime_start_thread.start()
 
     def _settings_tuple(self, endpoint: Optional[str] = None) -> tuple:
@@ -1411,7 +1403,7 @@ class OpenVikingMemoryProvider(MemoryProvider):
         self._env_refresh_enabled = True
         self._session_id = session_id
         self._turn_count = 0
-        self._hermes_home = str(kwargs.get("hermes_home") or "").strip() or str(_hermes_home_path())
+        self._hermes_home = str(kwargs.get("hermes_home") or "").strip() or str(get_hermes_home())
         self._acquire_run_lock()
         self._profile_prefetched_sessions.clear()
 
@@ -2078,7 +2070,7 @@ class OpenVikingMemoryProvider(MemoryProvider):
                     if after_discard is not None:
                         after_discard()
 
-        thread = threading.Thread(target=_run, daemon=True, name=name)
+        thread = spawn_context_thread(_run, name=name)
         with lock:
             if skip_if is not None and skip_if():
                 return
diff --git a/plugins/memory/retaindb/__init__.py b/plugins/memory/retaindb/__init__.py
index 1e421b3659..b5b236107c 100644
--- a/plugins/memory/retaindb/__init__.py
+++ b/plugins/memory/retaindb/__init__.py
@@ -22,7 +22,7 @@ from pathlib import Path
 from typing import Any, Callable
 from urllib.parse import quote
 
-from agent.memory_provider import MemoryProvider
+from agent.memory_provider import MemoryProvider, spawn_context_thread
 from agent.secret_scope import get_secret
 from agent.file_safety import raise_if_read_blocked
 from tools.registry import tool_error
@@ -186,7 +186,7 @@ class _WriteQueue:
 
     def __init__(self, client: _Client, db_path: Path):
         self._client, self._db_path, self._q = client, db_path, queue.Queue()
-        self._thread = threading.Thread(target=self._loop, name="retaindb-writer", daemon=True)
+        self._thread = spawn_context_thread(self._loop, name="retaindb-writer")
         db_path.parent.mkdir(parents=True, exist_ok=True)
         self._local = threading.local()  # one cached connection per thread, all tracked in _connections
         self._connections: set[sqlite3.Connection] = set()
@@ -346,7 +346,7 @@ class RetainDBMemoryProvider(MemoryProvider):
         soul = (home / "SOUL.md").read_text(encoding="utf-8", errors="replace").strip() if (home / "SOUL.md").exists() else ""
         if soul:  # seed agent identity from SOUL.md in background
             seed = lambda: self._client.seed_agent_identity(self._agent_id, soul, source="soul_md")  # noqa: E731
-            threading.Thread(target=_quiet, args=("soul seed", seed), name="retaindb-soul-seed", daemon=True).start()
+            spawn_context_thread(_quiet, args=("soul seed", seed), name="retaindb-soul-seed").start()
 
     def system_prompt_block(self) -> str:
         project = self._client.project if self._client else "retaindb"
@@ -368,7 +368,7 @@ class RetainDBMemoryProvider(MemoryProvider):
                 self._client.ask_user(self._user_id, query, reasoning_level=self._reasoning_level(query)).get("answer") or "") or None),
             ("retaindb-agent-model", "agent model", "_agent_model", lambda: self._agent_model_or_none(self._client.get_agent_model(self._agent_id))),
         )
-        self._prefetch_threads = [threading.Thread(target=self._store, args=(label, attr, fetch), name=name, daemon=True)
+        self._prefetch_threads = [spawn_context_thread(self._store, args=(label, attr, fetch), name=name)
                                   for name, label, attr, fetch in jobs]
         for t in self._prefetch_threads:
             t.start()
diff --git a/plugins/memory/supermemory/__init__.py b/plugins/memory/supermemory/__init__.py
index 49e8362e92..8b4ac247cc 100644
--- a/plugins/memory/supermemory/__init__.py
+++ b/plugins/memory/supermemory/__init__.py
@@ -13,7 +13,7 @@ from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any, Callable, Dict, List, Optional
 
-from agent.memory_provider import MemoryProvider
+from agent.memory_provider import MemoryProvider, spawn_context_thread
 from agent.secret_scope import get_secret, is_multiplex_active
 from tools.registry import tool_error
 
@@ -449,8 +449,8 @@ class SupermemoryMemoryProvider(MemoryProvider):
             return
         if self._write_thread and self._write_thread.is_alive():
             self._write_thread.join(timeout=2.0)
-        self._write_thread = threading.Thread(
-            target=_quietly, daemon=False, name="supermemory-memory-write",
+        self._write_thread = spawn_context_thread(
+            _quietly, daemon=False, name="supermemory-memory-write",
             args=(lambda: self._client.add_memory(content.strip(), metadata={"target": target, "type": "explicit_memory"},
                                                   entity_context=self._entity_context), "Supermemory on_memory_write failed"))
         self._write_thread.start()
diff --git a/tests/honcho_plugin/test_client_identity_isolation.py b/tests/honcho_plugin/test_client_identity_isolation.py
index ae278c2105..cc0cf07df7 100644
--- a/tests/honcho_plugin/test_client_identity_isolation.py
+++ b/tests/honcho_plugin/test_client_identity_isolation.py
@@ -155,7 +155,7 @@ class TestBackgroundThreadIsolation:
     def test_spawn_context_thread_sees_profile_override(self, tmp_path):
         """spawn_context_thread must carry the caller's HERMES_HOME override."""
         from hermes_constants import get_hermes_home
-        from plugins.memory.honcho.client import spawn_context_thread
+        from agent.memory_provider import spawn_context_thread
 
         home_b = tmp_path / "profiles" / "b"
         home_b.mkdir(parents=True)
diff --git a/tests/plugins/memory/test_holographic_save_config.py b/tests/plugins/memory/test_holographic_save_config.py
new file mode 100644
index 0000000000..cf6e473551
--- /dev/null
+++ b/tests/plugins/memory/test_holographic_save_config.py
@@ -0,0 +1,39 @@
+"""``save_config`` of the holographic provider writes config.yaml through the canonical writer.
+
+The provider used to ``yaml.dump`` straight over config.yaml, bypassing the config lock, the
+managed-mode refusal and the atomic replace. Two contracts pin the canonical path: unrelated
+sections survive a provider save, and a managed install refuses the write.
+"""
+from __future__ import annotations
+
+import yaml
+
+from plugins.memory.holographic import HolographicMemoryProvider
+
+
+def _provider():
+    return HolographicMemoryProvider(config={})
+
+
+def test_save_config_merges_into_existing_yaml(tmp_path, monkeypatch):
+    monkeypatch.setenv("HERMES_HOME", str(tmp_path))
+    (tmp_path / "config.yaml").write_text("model:\n  default: keep-me\nmemory:\n  provider: holographic\n")
+
+    _provider().save_config({"db_path": "custom.db", "hrr_dim": "512"}, str(tmp_path))
+
+    raw = yaml.safe_load((tmp_path / "config.yaml").read_text())
+    assert raw["plugins"]["hermes-memory-store"] == {"db_path": "custom.db", "hrr_dim": "512"}
+    assert raw["model"]["default"] == "keep-me"
+    assert raw["memory"]["provider"] == "holographic"
+
+
+def test_save_config_respects_managed_mode(tmp_path, monkeypatch):
+    monkeypatch.setenv("HERMES_HOME", str(tmp_path))
+    before = "model:\n  default: managed\n"
+    (tmp_path / "config.yaml").write_text(before)
+    monkeypatch.setattr("hermes_cli.config.is_managed", lambda: True)
+    monkeypatch.setattr("hermes_cli.config.managed_error", lambda *_a, **_k: None)
+
+    _provider().save_config({"db_path": "custom.db"}, str(tmp_path))
+
+    assert (tmp_path / "config.yaml").read_text() == before
diff --git a/tests/plugins/memory/test_provider_threads_inherit_profile.py b/tests/plugins/memory/test_provider_threads_inherit_profile.py
new file mode 100644
index 0000000000..5f2cfda9aa
--- /dev/null
+++ b/tests/plugins/memory/test_provider_threads_inherit_profile.py
@@ -0,0 +1,111 @@
+"""Multiplex invariant: every memory provider's background thread runs under the spawner's profile.
+
+Profile isolation is a ContextVar-scoped HERMES_HOME override; a plain ``threading.Thread`` starts
+with an EMPTY context, so a provider's prefetch/sync/writer thread would silently resolve the DEFAULT
+profile's home (and fail closed on scoped secrets). Each case drives the provider's real spawn path
+with a fake backend and asserts the thread saw the parent's home.
+"""
+from __future__ import annotations
+
+import threading
+from unittest.mock import MagicMock
+
+import pytest
+
+from hermes_constants import get_hermes_home, reset_hermes_home_override, set_hermes_home_override
+
+
+def _probe_home(seen: dict, key: str = "home"):
+    def _record(*_args, **_kwargs):
+        seen[key] = get_hermes_home()
+    return _record
+
+
+def _mem0(seen, tmp_path):
+    from plugins.memory.mem0 import Mem0MemoryProvider
+
+    p = Mem0MemoryProvider()
+    p._backend = MagicMock()
+    p._config = {"mode": "platform"}
+    p._add = _probe_home(seen)
+    p.sync_turn("a long enough user message", "assistant reply")
+    return [p._sync_thread]
+
+
+def _retaindb(seen, tmp_path):
+    import plugins.memory.retaindb as retaindb
+
+    p = retaindb.RetainDBMemoryProvider()
+    p._client = MagicMock()
+    p._context_overlay = lambda query: {"context": seen.setdefault("home", get_hermes_home()) and "ctx"}
+    p._client.ask_user.return_value = {"answer": ""}
+    p._client.get_agent_model.return_value = {}
+    p.queue_prefetch("what do you know")
+    return list(p._prefetch_threads)
+
+
+def _byterover(seen, tmp_path):
+    import plugins.memory.byterover as byterover
+
+    p = byterover.ByteRoverMemoryProvider()
+    p._curate = _probe_home(seen)
+    return [p._curate_in_background("content", name="brv-test", what="test")]
+
+
+def _supermemory(seen, tmp_path):
+    import plugins.memory.supermemory as supermemory
+
+    p = supermemory.SupermemoryMemoryProvider()
+    p._active = p._write_enabled = True
+    p._client = MagicMock()
+    p._client.add_memory = _probe_home(seen)
+    p.on_memory_write("add", "user", "a fact")
+    return [p._write_thread]
+
+
+def _openviking(seen, tmp_path):
+    import plugins.memory.openviking as openviking
+
+    p = openviking.OpenVikingMemoryProvider()
+    workers: set = set()
+    p._spawn_tracked("ov-test", _probe_home(seen), threading.Lock(), lambda: workers)
+    return list(workers)
+
+
+def _hindsight(seen, tmp_path):
+    import plugins.memory.hindsight as hindsight
+
+    p = hindsight.HindsightMemoryProvider()
+    p._recall_sync, p._memory_mode, p._auto_recall, p._prefetch_waits_for_retain = False, "hybrid", True, False
+    p._do_recall = lambda query: (seen.setdefault("home", get_hermes_home()) and "text", 1)
+    p.queue_prefetch("remember this")
+    return [p._prefetch_thread]
+
+
+def _honcho(seen, tmp_path):
+    from plugins.memory.honcho import HonchoMemoryProvider
+
+    return [HonchoMemoryProvider._spawn_write(_probe_home(seen), "honcho-test", "failed %s")]
+
+
+_PROVIDERS = {
+    "mem0": _mem0, "retaindb": _retaindb, "byterover": _byterover, "supermemory": _supermemory,
+    "openviking": _openviking, "hindsight": _hindsight, "honcho": _honcho,
+}
+
+
+@pytest.mark.parametrize("name", sorted(_PROVIDERS))
+def test_provider_background_thread_sees_spawner_profile_home(name, tmp_path, monkeypatch):
+    monkeypatch.setenv("HERMES_HOME", str(tmp_path / "default"))
+    profile_home = tmp_path / "profiles" / "b"
+    profile_home.mkdir(parents=True)
+    seen: dict = {}
+    token = set_hermes_home_override(profile_home)
+    try:
+        threads = _PROVIDERS[name](seen, tmp_path)
+    finally:
+        reset_hermes_home_override(token)
+    for t in threads:
+        if t is not None:
+            t.join(timeout=10)
+    assert seen.get("home") == profile_home, f"{name}: background thread resolved {seen.get('home')}"
diff --git a/utils.py b/utils.py
index dabf197d07..d6d46489b0 100644
--- a/utils.py
+++ b/utils.py
@@ -313,6 +313,18 @@ def atomic_json_write(
                   fsync_dir=fsync_dir)
 
 
+def read_json_or_empty(path: Union[str, Path]) -> dict:
+    """The JSON object at *path*, or ``{}`` when the file is missing, unreadable, malformed or
+    not an object. The read half of every ``read → merge → atomic_json_write`` config store
+    (memory-provider ``save_config``), so a corrupt sidecar degrades to defaults instead of
+    taking the provider down."""
+    try:
+        data = json.loads(Path(path).read_text(encoding="utf-8"))
+    except (OSError, ValueError):
+        return {}
+    return data if isinstance(data, dict) else {}
+
+
 def warn_if_credential_file_broadly_readable(path: Union[str, Path], *, label: str = "", log: logging.Logger | None = None) -> bool:
     """Warn when a credential file is group/world-readable; True when a warning was emitted.