feat(hooks): add daemon-strict mode to prevent concurrent local writes

jphein · claude · jphein · commit 0e97b19d78ae · 2026-04-24T20:30:26.000-07:00
When PALACE_DAEMON_URL is set, hooks now skip all local palace writes
(both auto-ingest mining and silent-save fallback) instead of writing
to a local SQLite. The daemon at the URL is treated as the single
source of truth.

Without this, hooks fired from any session could create a second writer
on the SQLite file — under Syncthing replication this produces sync
conflicts and disk-image corruption (see incident 2026-04-24).

Set PALACE_DAEMON_STRICT=0 to opt back into the old fall-through-on-
daemon-failure behavior.

Co-Authored-By: Claude Opus 4.7 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/.claude-plugin/hooks/hooks.json b/.claude-plugin/hooks/hooks.json
@@ -16,7 +16,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "bash ${CLAUDE_PLUGIN_ROOT}/hooks/mempal-precompact-hook.sh"
+            "command": "PALACE_DAEMON_URL=http://disks.jphe.in:8085 PALACE_API_KEY=adb43b99effac3aced2c82de54827850c6da1fbf4a5e473e1938529b27c08ab3 bash ${CLAUDE_PLUGIN_ROOT}/hooks/mempal-precompact-hook.sh"
           }
         ]
       }
diff --git a/mempalace/hooks_cli.py b/mempalace/hooks_cli.py
@@ -263,8 +263,19 @@ def _spawn_mine(cmd: list) -> None:
     _MINE_PID_FILE.write_text(str(proc.pid))
 
 
+def _daemon_strict() -> bool:
+    """When PALACE_DAEMON_URL is set and STRICT mode is on, skip all local writes."""
+    return (
+        os.environ.get("PALACE_DAEMON_URL", "").strip() != ""
+        and os.environ.get("PALACE_DAEMON_STRICT", "1") != "0"
+    )
+
+
 def _maybe_auto_ingest(transcript_path: str = ""):
     """Run mempalace mine in background if a mine directory is available."""
+    if _daemon_strict():
+        _log("Skipping auto-ingest: PALACE_DAEMON_URL set, daemon owns writes")
+        return
     mine_dir = _get_mine_dir(transcript_path)
     if not mine_dir:
         return
@@ -279,6 +290,9 @@ def _maybe_auto_ingest(transcript_path: str = ""):
 
 def _mine_sync(transcript_path: str = ""):
     """Run mempalace mine synchronously (for precompact -- data must land first)."""
+    if _daemon_strict():
+        _log("Skipping sync mine: PALACE_DAEMON_URL set, daemon owns writes")
+        return
     mine_dir = _get_mine_dir(transcript_path)
     if not mine_dir:
         return
@@ -454,7 +468,18 @@ def _save_diary_direct(
                 "queued": daemon_result.get("queued", False),
             }
         except Exception as e:
-            _log(f"Daemon silent-save failed ({e}); falling through to direct write")
+            _log(f"Daemon silent-save failed ({e})")
+            # Strict mode: when PALACE_DAEMON_URL is set, NEVER fall through to direct write.
+            # Daemon is single source of truth; concurrent local writes corrupt SQLite under
+            # Syncthing replication. Drop the save and surface the error instead.
+            if os.environ.get("PALACE_DAEMON_STRICT", "1") != "0":
+                return {
+                    "count": 0,
+                    "themes": themes,
+                    "systemMessage": f"⚠ Save dropped — daemon at {daemon_url} unreachable: {e}",
+                    "queued": False,
+                }
+            _log("PALACE_DAEMON_STRICT=0 — falling through to direct write")
 
     try:
         from .mcp_server import tool_diary_write

Original file line number	Diff line number	Diff line change
`@@ -16,7 +16,7 @@`
`16`	`16`	`"hooks": [`
`17`	`17`	`{`
`18`	`18`	`"type": "command",`
`19`		`- "command": "bash ${CLAUDE_PLUGIN_ROOT}/hooks/mempal-precompact-hook.sh"`
	`19`	`+ "command": "PALACE_DAEMON_URL=http://disks.jphe.in:8085 PALACE_API_KEY=adb43b99effac3aced2c82de54827850c6da1fbf4a5e473e1938529b27c08ab3 bash ${CLAUDE_PLUGIN_ROOT}/hooks/mempal-precompact-hook.sh"`
`20`	`20`	`}`
`21`	`21`	`]`
`22`	`22`	`}`