fix(store): honor limit parameter in Redis search operations (#30)

  The RedisStore and AsyncRedisStore search methods were hardcoded to return at most 10 results regardless of the specified limit parameter. This fix properly respects the
  user-specified limit when searching, enabling retrieval of more than 10 results when needed.

  - Modified _get_batch_search_queries to return limit and offset values
  - Updated search query creation to use Query.paging() method with the user-specified limit
  - Added integration tests to verify fix in both sync and async implementations

Author: bsbodden

langgraph/store/redis/__init__.py

@@ -367,7 +367,7 @@ def _batch_search_ops(
             query_vectors = dict(zip([idx for idx, _ in embedding_requests], vectors))
 
         # Process each search operation
-        for (idx, op), (query_str, params) in zip(search_ops, queries):
+        for (idx, op), (query_str, params, limit, offset) in zip(search_ops, queries):
             if op.query and idx in query_vectors:
                 # Vector similarity search
                 vector = query_vectors[idx]
@@ -376,7 +376,7 @@ def _batch_search_ops(
                     vector_field_name="embedding",
                     filter_expression=f"@prefix:{_namespace_to_text(op.namespace_prefix)}*",
                     return_fields=["prefix", "key", "vector_distance"],
-                    num_results=op.limit,
+                    num_results=limit,  # Use the user-specified limit
                 )
                 vector_results = self.vector_index.query(vector_query)
 
@@ -469,8 +469,10 @@ def _batch_search_ops(
                 results[idx] = items
             else:
                 # Regular search
-                query = Query(query_str)
-                # Get all potential matches for filtering
+                # Create a query with LIMIT and OFFSET parameters
+                query = Query(query_str).paging(offset, limit)
+
+                # Execute search with limit and offset applied by Redis
                 res = self.store_index.search(query)
                 items = []
                 refresh_keys = []  # Track keys that need TTL refreshed
@@ -505,10 +507,7 @@ def _batch_search_ops(
 
                     items.append(_row_to_search_item(_decode_ns(data["prefix"]), data))
 
-                # Apply pagination after filtering
-                if params:
-                    limit, offset = params
-                    items = items[offset : offset + limit]
+                # Note: Pagination is now handled by Redis, no need to slice items manually
 
                 # Refresh TTL if requested
                 if op.refresh_ttl and refresh_keys and self.ttl_config:

langgraph/store/redis/aio.py

@@ -648,7 +648,7 @@ async def _batch_search_ops(
             query_vectors = dict(zip([idx for idx, _ in embedding_requests], vectors))
 
         # Process each search operation
-        for (idx, op), (query_str, params) in zip(search_ops, queries):
+        for (idx, op), (query_str, params, limit, offset) in zip(search_ops, queries):
             if op.query and idx in query_vectors:
                 # Vector similarity search
                 vector = query_vectors[idx]
@@ -658,7 +658,7 @@ async def _batch_search_ops(
                         vector_field_name="embedding",
                         filter_expression=f"@prefix:{_namespace_to_text(op.namespace_prefix)}*",
                         return_fields=["prefix", "key", "vector_distance"],
-                        num_results=op.limit,
+                        num_results=limit,  # Use the user-specified limit
                     )
                 )
 
@@ -722,8 +722,10 @@ async def _batch_search_ops(
                 results[idx] = items
             else:
                 # Regular search
-                query = Query(query_str)
-                # Get all potential matches for filtering
+                # Create a query with LIMIT and OFFSET parameters
+                query = Query(query_str).paging(offset, limit)
+
+                # Execute search with limit and offset applied by Redis
                 res = await self.store_index.search(query)
                 items = []
 
@@ -746,12 +748,9 @@ async def _batch_search_ops(
                             continue
                     items.append(_row_to_search_item(_decode_ns(data["prefix"]), data))
 
-            # Apply pagination after filtering
-            if params:
-                limit, offset = params
-                items = items[offset : offset + limit]
+                # Note: Pagination is now handled by Redis, no need to slice items manually
 
-            results[idx] = items
+                results[idx] = items
 
     async def _batch_list_namespaces_ops(
         self,

langgraph/store/redis/base.py

@@ -398,7 +398,7 @@ def _prepare_batch_PUT_queries(
     def _get_batch_search_queries(
         self,
         search_ops: Sequence[tuple[int, SearchOp]],
-    ) -> tuple[list[tuple[str, list]], list[tuple[int, str]]]:
+    ) -> tuple[list[tuple[str, list, int, int]], list[tuple[int, str]]]:
         """Convert search operations into Redis queries."""
         queries = []
         embedding_requests = []
@@ -413,8 +413,10 @@ def _get_batch_search_queries(
                 embedding_requests.append((idx, op.query))
 
             query = " ".join(filter_conditions) if filter_conditions else "*"
-            params = [op.limit, op.offset] if op.limit or op.offset else []
-            queries.append((query, params))
+            limit = op.limit if op.limit is not None else 10
+            offset = op.offset if op.offset is not None else 0
+            params = [limit, offset]
+            queries.append((query, params, limit, offset))
 
         return queries, embedding_requests
 

tests/test_async_search_limit.py

@@ -0,0 +1,73 @@
+"""Tests for AsyncRedisStore search limits."""
+
+from __future__ import annotations
+
+import pytest
+import pytest_asyncio
+
+from langgraph.store.redis import AsyncRedisStore
+
+
+@pytest_asyncio.fixture(scope="function")
+async def async_store(redis_url) -> AsyncRedisStore:
+    """Fixture to create an AsyncRedisStore."""
+    async with AsyncRedisStore(redis_url) as store:
+        await store.setup()  # Initialize indices
+        yield store
+
+
+@pytest.mark.asyncio
+async def test_async_search_with_larger_limit(async_store: AsyncRedisStore) -> None:
+    """Test async search with limit > 10."""
+    # Create 15 test documents
+    for i in range(15):
+        await async_store.aput(
+            ("test_namespace",), f"key{i}", {"data": f"value{i}", "index": i}
+        )
+
+    # Search with a limit of 15
+    results = await async_store.asearch(("test_namespace",), limit=15)
+
+    # Should return all 15 results
+    assert len(results) == 15, f"Expected 15 results, got {len(results)}"
+
+    # Verify we have all the items
+    result_keys = {item.key for item in results}
+    expected_keys = {f"key{i}" for i in range(15)}
+    assert result_keys == expected_keys
+
+
+@pytest.mark.asyncio
+async def test_async_vector_search_with_larger_limit(redis_url) -> None:
+    """Test async vector search with limit > 10."""
+    from tests.embed_test_utils import CharacterEmbeddings
+
+    # Create vector store with embeddings
+    embeddings = CharacterEmbeddings(dims=4)
+    index_config = {
+        "dims": embeddings.dims,
+        "embed": embeddings,
+        "distance_type": "cosine",
+        "fields": ["text"],
+    }
+
+    async with AsyncRedisStore(redis_url, index=index_config) as store:
+        await store.setup()
+
+        # Create 15 test documents
+        for i in range(15):
+            # Create documents with slightly different texts
+            await store.aput(
+                ("test_namespace",), f"key{i}", {"text": f"sample text {i}", "index": i}
+            )
+
+        # Search with a limit of 15
+        results = await store.asearch(("test_namespace",), query="sample", limit=15)
+
+        # Should return all 15 results
+        assert len(results) == 15, f"Expected 15 results, got {len(results)}"
+
+        # Verify we have all the items
+        result_keys = {item.key for item in results}
+        expected_keys = {f"key{i}" for i in range(15)}
+        assert result_keys == expected_keys

tests/test_search_limit.py

@@ -0,0 +1,68 @@
+"""Tests for RedisStore search limits."""
+
+from __future__ import annotations
+
+import pytest
+
+from langgraph.store.redis import RedisStore
+
+
+@pytest.fixture(scope="function")
+def store(redis_url) -> RedisStore:
+    """Fixture to create a Redis store."""
+    with RedisStore.from_conn_string(redis_url) as store:
+        store.setup()  # Initialize indices
+        yield store
+
+
+def test_search_with_larger_limit(store: RedisStore) -> None:
+    """Test search with limit > 10."""
+    # Create 15 test documents
+    for i in range(15):
+        store.put(("test_namespace",), f"key{i}", {"data": f"value{i}", "index": i})
+
+    # Search with a limit of 15
+    results = store.search(("test_namespace",), limit=15)
+
+    # Should return all 15 results
+    assert len(results) == 15, f"Expected 15 results, got {len(results)}"
+
+    # Verify we have all the items
+    result_keys = {item.key for item in results}
+    expected_keys = {f"key{i}" for i in range(15)}
+    assert result_keys == expected_keys
+
+
+def test_vector_search_with_larger_limit(redis_url) -> None:
+    """Test vector search with limit > 10."""
+    from tests.embed_test_utils import CharacterEmbeddings
+
+    # Create vector store with embeddings
+    embeddings = CharacterEmbeddings(dims=4)
+    index_config = {
+        "dims": embeddings.dims,
+        "embed": embeddings,
+        "distance_type": "cosine",
+        "fields": ["text"],
+    }
+
+    with RedisStore.from_conn_string(redis_url, index=index_config) as store:
+        store.setup()
+
+        # Create 15 test documents
+        for i in range(15):
+            # Create documents with slightly different texts
+            store.put(
+                ("test_namespace",), f"key{i}", {"text": f"sample text {i}", "index": i}
+            )
+
+        # Search with a limit of 15
+        results = store.search(("test_namespace",), query="sample", limit=15)
+
+        # Should return all 15 results
+        assert len(results) == 15, f"Expected 15 results, got {len(results)}"
+
+        # Verify we have all the items
+        result_keys = {item.key for item in results}
+        expected_keys = {f"key{i}" for i in range(15)}
+        assert result_keys == expected_keys