diff --git a/navi/memory/migrate_pgvector.py b/navi/memory/migrate_pgvector.py
new file mode 100644
index 0000000..edb9c93
--- /dev/null
+++ b/navi/memory/migrate_pgvector.py
@@ -0,0 +1,76 @@
+"""Database migration script for memory system pgvector upgrade.
+
+Run this once against the PostgreSQL database after deploying the new code:
+    .venv/bin/python navi/memory/migrate_pgvector.py
+
+What it does:
+1. Verifies pgvector extension is installed
+2. Adds missing columns to memory_facts: embedding, source, confidence, expires_at, last_verified_at, source_context
+3. Creates indexes: hnsw on embedding, expires (partial), source+category
+
+Safe to run multiple times — all operations use IF NOT EXISTS.
+"""
+
+import asyncio
+import sys
+
+import asyncpg
+
+
+async def migrate(dsn: str) -> None:
+    conn = await asyncpg.connect(dsn)
+    try:
+        has_vec = bool(await conn.fetchval("SELECT 1 FROM pg_extension WHERE extname = 'vector'"))
+        print(f"pgvector available: {has_vec}")
+
+        alter_stmts: list[str] = []
+        if has_vec:
+            alter_stmts.append("ALTER TABLE memory_facts ADD COLUMN IF NOT EXISTS embedding vector(768)")
+
+        alter_stmts.extend(
+            [
+                "ALTER TABLE memory_facts ADD COLUMN IF NOT EXISTS source TEXT NOT NULL DEFAULT 'conversation'",
+                "ALTER TABLE memory_facts ADD COLUMN IF NOT EXISTS confidence SMALLINT NOT NULL DEFAULT 70",
+                "ALTER TABLE memory_facts ADD COLUMN IF NOT EXISTS expires_at TIMESTAMPTZ",
+                "ALTER TABLE memory_facts ADD COLUMN IF NOT EXISTS last_verified_at TIMESTAMPTZ",
+                "ALTER TABLE memory_facts ADD COLUMN IF NOT EXISTS source_context TEXT",
+            ]
+        )
+
+        for stmt in alter_stmts:
+            try:
+                await conn.execute(stmt)
+                print(f"  OK: {stmt[:70]}...")
+            except Exception as e:
+                print(f"  FAIL: {stmt[:70]}... - {e}")
+
+        index_stmts = [
+            "CREATE INDEX IF NOT EXISTS idx_memory_facts_expires ON memory_facts (expires_at) WHERE expires_at IS NOT NULL",
+            "CREATE INDEX IF NOT EXISTS idx_memory_facts_source_cat ON memory_facts (source, category)",
+        ]
+        if has_vec:
+            index_stmts.append(
+                "CREATE INDEX IF NOT EXISTS idx_memory_facts_embedding ON memory_facts USING hnsw (embedding vector_cosine_ops)"
+            )
+
+        for stmt in index_stmts:
+            try:
+                await conn.execute(stmt)
+                print(f"  OK: {stmt[:80]}...")
+            except Exception as e:
+                print(f"  FAIL: {stmt[:80]}... - {e}")
+
+        print("Migration complete.")
+    finally:
+        await conn.close()
+
+
+if __name__ == "__main__":
+    from navi.config import settings
+
+    dsn = settings.database_url
+    if not dsn:
+        print("No DATABASE_URL set — nothing to migrate.")
+        sys.exit(0)
+
+    asyncio.run(migrate(dsn))