fix(fts): scope memories_fts update triggers to indexed columns

db/migrations/083_fts_trigger_scope.sql

@@ -0,0 +1,31 @@
+-- Migration 083: scope memories_fts update triggers (issue #152)
+--
+-- The unscoped AFTER UPDATE triggers fired on every metadata write, so each
+-- memory_search (via _retrieval_practice_boost) eroded the external-content
+-- FTS5 index. Scope them to the indexed columns. The one-time rebuild
+-- repairs indexes already corrupted in the field.
+--
+-- Rollback:
+--   restore the unscoped triggers from migration 052
+--   DELETE FROM schema_version WHERE version = 83;
+--
+-- IDEMPOTENT.
+
+DROP TRIGGER IF EXISTS memories_fts_update_delete;
+DROP TRIGGER IF EXISTS memories_fts_update_insert;
+
+CREATE TRIGGER memories_fts_update_delete AFTER UPDATE OF content, category, tags, indexed, retired_at ON memories WHEN old.indexed = 1 BEGIN
+    INSERT INTO memories_fts(memories_fts, rowid, content, category, tags)
+    VALUES ('delete', old.id, old.content, old.category, old.tags);
+END;
+
+CREATE TRIGGER memories_fts_update_insert AFTER UPDATE OF content, category, tags, indexed, retired_at ON memories WHEN new.indexed = 1 AND new.retired_at IS NULL BEGIN
+    INSERT INTO memories_fts(rowid, content, category, tags)
+    VALUES (new.id, new.content, new.category, new.tags);
+END;
+
+INSERT INTO memories_fts(memories_fts) VALUES('rebuild');
+
+INSERT OR IGNORE INTO schema_version (version, description, applied_at)
+VALUES (83, 'scope memories_fts update triggers (issue #152)',
+        strftime('%Y-%m-%dT%H:%M:%S', 'now'));

src/agentmemory/db/init_schema.sql

@@ -132,19 +132,15 @@ CREATE TRIGGER memories_fts_insert AFTER INSERT ON memories WHEN new.indexed = 1
     INSERT INTO memories_fts(rowid, content, category, tags) VALUES (new.id, new.content, new.category, new.tags);
 END;
 
--- Split into two triggers so 0→1 promotion correctly adds to FTS without double-delete.
--- Added `NEW.retired_at IS NULL` guard on the INSERT leg so retire UPDATEs
--- (retired_at NULL → non-NULL) do not re-insert the row. The companion
--- trg_memories_fts_purge_on_retire trigger near the end of this file does
--- the actual DELETE at the retire transition; without this guard, the
--- 'delete' command issued there is silently no-op'd by FTS5 statement-level
--- batching against the pending INSERT.
-CREATE TRIGGER memories_fts_update_delete AFTER UPDATE ON memories WHEN old.indexed = 1 BEGIN
+-- Update triggers scoped to FTS columns (plus indexed, retired_at) so
+-- metadata-only updates don't churn the index (issue #152). The
+-- retired_at IS NULL guard drops the re-insert at the retire transition.
+CREATE TRIGGER memories_fts_update_delete AFTER UPDATE OF content, category, tags, indexed, retired_at ON memories WHEN old.indexed = 1 BEGIN
     INSERT INTO memories_fts(memories_fts, rowid, content, category, tags)
     VALUES ('delete', old.id, old.content, old.category, old.tags);
 END;
 
-CREATE TRIGGER memories_fts_update_insert AFTER UPDATE ON memories WHEN new.indexed = 1 AND new.retired_at IS NULL BEGIN
+CREATE TRIGGER memories_fts_update_insert AFTER UPDATE OF content, category, tags, indexed, retired_at ON memories WHEN new.indexed = 1 AND new.retired_at IS NULL BEGIN
     INSERT INTO memories_fts(rowid, content, category, tags)
     VALUES (new.id, new.content, new.category, new.tags);
 END;

src/agentmemory/mcp_server.py

@@ -346,10 +346,44 @@ def _ensure_fts_index_consistent(conn) -> bool:
             return False
     except sqlite3.Error:
         return False
-
     return False
 
 
+_SCOPED_FTS_UPDATE_TRIGGERS = """
+DROP TRIGGER IF EXISTS memories_fts_update_delete;
+DROP TRIGGER IF EXISTS memories_fts_update_insert;
+CREATE TRIGGER memories_fts_update_delete AFTER UPDATE OF content, category, tags, indexed, retired_at ON memories WHEN old.indexed = 1 BEGIN
+    INSERT INTO memories_fts(memories_fts, rowid, content, category, tags)
+    VALUES ('delete', old.id, old.content, old.category, old.tags);
+END;
+CREATE TRIGGER memories_fts_update_insert AFTER UPDATE OF content, category, tags, indexed, retired_at ON memories WHEN new.indexed = 1 AND new.retired_at IS NULL BEGIN
+    INSERT INTO memories_fts(rowid, content, category, tags)
+    VALUES (new.id, new.content, new.category, new.tags);
+END;
+"""
+
+
+def _ensure_fts_triggers_scoped(conn) -> bool:
+    """Replace legacy unscoped memories_fts update triggers with column-scoped
+    ones (issue #152). Idempotent; returns True only if it rewrote them."""
+    try:
+        rows = conn.execute(
+            "SELECT sql FROM sqlite_master WHERE type='trigger' "
+            "AND name IN ('memories_fts_update_delete', 'memories_fts_update_insert')"
+        ).fetchall()
+    except sqlite3.Error:
+        return False
+    if not rows or all(r[0] and "AFTER UPDATE OF" in r[0].upper() for r in rows):
+        return False
+    try:
+        conn.executescript(_SCOPED_FTS_UPDATE_TRIGGERS)
+        conn.execute("INSERT INTO memories_fts(memories_fts) VALUES('rebuild')")
+        conn.commit()
+        return True
+    except sqlite3.Error:
+        return False
+
+
 def ensure_agent(conn, agent_id: str) -> None:
     if not agent_id:
         return
@@ -3640,6 +3674,21 @@ def _ensure_db_initialized() -> None:
             file=sys.stderr,
         )
 
+    # Heal legacy unscoped memories_fts update triggers (issue #152) on
+    # installs that predate migration 083 or never run migrations.
+    try:
+        conn = sqlite3.connect(str(db_path), timeout=10)
+        try:
+            if _ensure_fts_triggers_scoped(conn):
+                print(
+                    f"brainctl-mcp: rescoped memories_fts update triggers for {db_path}",
+                    file=sys.stderr,
+                )
+        finally:
+            conn.close()
+    except sqlite3.Error:
+        pass
+
 
 def run():
     """Synchronous entry point for pyproject.toml console_scripts."""

tests/bench/baselines/search_quality.json

@@ -2,27 +2,27 @@
   "by_category": {
     "ambiguous": {
       "count": 1,
-      "mrr": 0.0,
-      "ndcg_at_5": 0.0,
-      "p_at_1": 0.0,
-      "p_at_5": 0.0,
-      "recall_at_5": 0.0
+      "mrr": 1.0,
+      "ndcg_at_5": 1.0,
+      "p_at_1": 1.0,
+      "p_at_5": 0.6,
+      "recall_at_5": 1.0
     },
     "decision": {
       "count": 3,
-      "mrr": 0.3333,
-      "ndcg_at_5": 0.3186,
-      "p_at_1": 0.3333,
-      "p_at_5": 0.1333,
-      "recall_at_5": 0.3333
+      "mrr": 1.0,
+      "ndcg_at_5": 1.0,
+      "p_at_1": 1.0,
+      "p_at_5": 0.3333,
+      "recall_at_5": 1.0
     },
     "entity": {
       "count": 7,
-      "mrr": 0.7143,
-      "ndcg_at_5": 0.6099,
-      "p_at_1": 0.7143,
-      "p_at_5": 0.2,
-      "recall_at_5": 0.4524
+      "mrr": 1.0,
+      "ndcg_at_5": 0.8474,
+      "p_at_1": 1.0,
+      "p_at_5": 0.2857,
+      "recall_at_5": 0.6429
     },
     "negative": {
       "count": 1,
@@ -35,37 +35,37 @@
     "procedural": {
       "count": 4,
       "mrr": 0.875,
-      "ndcg_at_5": 0.6333,
+      "ndcg_at_5": 0.8032,
       "p_at_1": 0.75,
-      "p_at_5": 0.25,
-      "recall_at_5": 0.75
+      "p_at_5": 0.3,
+      "recall_at_5": 0.875
     },
     "temporal": {
       "count": 2,
-      "mrr": 1.0,
-      "ndcg_at_5": 0.8936,
-      "p_at_1": 1.0,
-      "p_at_5": 0.3,
-      "recall_at_5": 0.75
+      "mrr": 0.4167,
+      "ndcg_at_5": 0.5335,
+      "p_at_1": 0.0,
+      "p_at_5": 0.4,
+      "recall_at_5": 1.0
     },
     "troubleshooting": {
       "count": 2,
-      "mrr": 0.5,
-      "ndcg_at_5": 0.3066,
-      "p_at_1": 0.5,
-      "p_at_5": 0.1,
-      "recall_at_5": 0.25
+      "mrr": 1.0,
+      "ndcg_at_5": 1.0,
+      "p_at_1": 1.0,
+      "p_at_5": 0.3,
+      "recall_at_5": 1.0
     }
   },
   "k": 10,
   "overall": {
-    "mrr": 0.625,
+    "mrr": 0.8667,
     "n_queries": 20,
-    "ndcg_at_10": 0.5579,
-    "ndcg_at_5": 0.5579,
-    "p_at_1": 0.6,
-    "p_at_5": 0.18,
-    "recall_at_10": 0.5083,
-    "recall_at_5": 0.5083
+    "ndcg_at_10": 0.8606,
+    "ndcg_at_5": 0.8606,
+    "p_at_1": 0.8,
+    "p_at_5": 0.31,
+    "recall_at_10": 0.85,
+    "recall_at_5": 0.85
   }
 }