fix(core): chunk select_by_ids to stay under SQLite bound-parameter limit

src/basic_memory/repository/repository.py

@@ -23,6 +23,12 @@
 
 T = TypeVar("T", bound=Base)
 
+# SQLite caps the number of bound parameters per statement (999 on builds older
+# than 3.32.0), so id-list queries must stay below that floor. 500 leaves
+# headroom for additional binds (e.g. the project_id filter) while keeping the
+# number of round-trips low.
+SELECT_BY_IDS_CHUNK_SIZE = 500
+
 
 class Repository[T: Base]:
     """Base repository implementation with explicit caller-owned sessions."""
@@ -83,15 +89,25 @@ async def select_by_id(self, session: AsyncSession, entity_id: int) -> Optional[
         return result.scalars().one_or_none()
 
     async def select_by_ids(self, session: AsyncSession, ids: List[int]) -> Sequence[T]:
-        """Select multiple entities by IDs using an existing session."""
-        query = (
-            select(self.Model).where(self.primary_key.in_(ids)).options(*self.get_load_options())
-        )
-        # Add project filter if applicable
-        query = self._add_project_filter(query)
+        """Select multiple entities by IDs using an existing session.
 
-        result = await session.execute(query)
-        return result.scalars().all()
+        Queries in chunks so callers can pass arbitrarily large id lists
+        without hitting SQLite's bound-parameter limit (issue #1045).
+        """
+        results: list[T] = []
+        for start in range(0, len(ids), SELECT_BY_IDS_CHUNK_SIZE):
+            chunk = ids[start : start + SELECT_BY_IDS_CHUNK_SIZE]
+            query = (
+                select(self.Model)
+                .where(self.primary_key.in_(chunk))
+                .options(*self.get_load_options())
+            )
+            # Add project filter if applicable
+            query = self._add_project_filter(query)
+
+            result = await session.execute(query)
+            results.extend(result.scalars().all())
+        return results
 
     async def add(self, session: AsyncSession, model: T) -> T:
         """

tests/repository/test_repository.py

@@ -1,6 +1,8 @@
 """Test repository implementation."""
 
 from datetime import datetime, UTC
+from unittest.mock import AsyncMock
+
 import pytest
 from sqlalchemy import String, DateTime
 from sqlalchemy.orm import Mapped, mapped_column
@@ -133,6 +135,29 @@ async def test_find_by_ids(repository, session_maker):
         assert len(not_found) == 0
 
 
+@pytest.mark.asyncio
+async def test_find_by_ids_chunks_large_requests(repository, session_maker, monkeypatch):
+    """Regression test for #1045: bulk id hydration must issue bounded queries."""
+    instances = [ModelTest(id=f"test_{i}", name=f"Test {i}") for i in range(5)]
+    async with db.scoped_session(session_maker) as session:
+        await repository.add_all_no_return(session, instances)
+
+        # Use a tiny deterministic chunk size so this test proves the query is
+        # split even on SQLite builds whose real parameter cap exceeds 1,100.
+        monkeypatch.setattr(
+            "basic_memory.repository.repository.SELECT_BY_IDS_CHUNK_SIZE",
+            2,
+        )
+        execute = AsyncMock(wraps=session.execute)
+        monkeypatch.setattr(session, "execute", execute)
+
+        ids_to_find = [instance.id for instance in instances]
+        found = await repository.find_by_ids(session, ids_to_find)
+
+        assert execute.await_count == 3
+        assert sorted(e.id for e in found) == sorted(ids_to_find)
+
+
 @pytest.mark.asyncio
 async def test_delete_by_ids(repository, session_maker):
     """Test finding multiple entities by IDs."""