Base classes and types for persistent key-value stores.
Stores provide long-term memory that persists across threads and conversations. Supports hierarchical namespaces, key-value storage, and optional vector search.
Core types:
BaseStore: Store interface with sync/async operationsItem: Stored key-value pairs with metadataOp: Get/Put/Search/List operationsType for asynchronous embedding functions.
Similar to EmbeddingsFunc, but returns an awaitable that resolves to the embeddings.
Type for synchronous embedding functions.
The function should take a sequence of strings and return a list of embeddings, where each embedding is a list of floats. The dimensionality of the embeddings should be consistent for all inputs.
Specifies how to match namespace paths.
Ensure that an embedding function conforms to LangChain's Embeddings interface.
This function wraps arbitrary embedding functions to make them compatible with LangChain's Embeddings interface. It handles both synchronous and asynchronous functions.
Extract text from an object using a path expression or pre-tokenized path.
Tokenize a path into components.
A tuple representing a namespace path that can include wildcards.
("users",) # Exact users namespace
("documents", "*") # Any sub-namespace under documents
("cache", "*", "v1") # Any cache category with v1 versionSentinel singleton.
Represents a stored item with metadata.
Represents an item returned from a search operation with additional metadata.
Operation to store, update, or delete an item in the store.
This class represents a single operation to modify the store's contents, whether adding new items, updating existing ones, or removing them.
Provided namespace is invalid.
Configuration for TTL (time-to-live) behavior in the store.
Configuration for indexing documents for semantic search in the store.
If not provided to the store, the store will not support vector search.
In that case, all index arguments to put() and aput() operations will be ignored.
Abstract base class for persistent key-value stores.
Stores enable persistence and memory that can be shared across threads,
scoped to user IDs, assistant IDs, or other arbitrary namespaces.
Some implementations may support semantic search capabilities through
an optional index configuration.
Utilities for batching operations in a background task.
Utilities for working with embedding functions and LangChain's Embeddings interface.
This module provides tools to wrap arbitrary embedding functions (both sync and async) into LangChain's Embeddings interface. This enables using custom embedding functions with LangChain-compatible tools while maintaining support for both synchronous and asynchronous operations.
Operation to retrieve a specific item by its namespace and key.
This operation allows precise retrieval of stored items using their full path (namespace) and unique identifier (key) combination.
Basic item retrieval:
GetOp(namespace=("users", "profiles"), key="user123")
GetOp(namespace=("cache", "embeddings"), key="doc456")Operation to search for items within a specified namespace hierarchy.
This operation supports both structured filtering and natural language search within a given namespace prefix. It provides pagination through limit and offset parameters.
Natural language search support depends on your store implementation.
Search with filters and pagination:
SearchOp(
namespace_prefix=("documents",),
filter={"type": "report", "status": "active"},
limit=5,
offset=10
)
Natural language search:
SearchOp(
namespace_prefix=("users", "content"),
query="technical documentation about APIs",
limit=20
)Represents a pattern for matching namespaces in the store.
This class combines a match type (prefix or suffix) with a namespace path pattern that can include wildcards to flexibly match different namespace hierarchies.
Prefix matching:
MatchCondition(match_type="prefix", path=("users", "profiles"))
Suffix matching with wildcard:
MatchCondition(match_type="suffix", path=("cache", "*"))
Simple suffix matching:
MatchCondition(match_type="suffix", path=("v1",))Operation to list and filter namespaces in the store.
This operation allows exploring the organization of data, finding specific collections, and navigating the namespace hierarchy.
List all namespaces under the "documents" path:
ListNamespacesOp(
match_conditions=(MatchCondition(match_type="prefix", path=("documents",)),),
max_depth=2
)
List all namespaces that end with "v1":
ListNamespacesOp(
match_conditions=(MatchCondition(match_type="suffix", path=("v1",)),),
limit=50
)