OpenViking/integrations/langchain

langchain-openviking

langchain-openviking is the official OpenViking integration package for LangChain and LangGraph applications. It keeps framework-specific adapters separate from the OpenViking server and communicates with remote OpenViking instances through the lightweight openviking-sdk package.

OpenViking Server requirement: examples here use the viking://~ home alias (for example viking://~/memories), which the server expands to the authenticated caller's own user space, so they require a server with viking://~ support. The uid-less viking://user/memories shorthand is rejected by newer servers; pass an explicit viking://user/<uid>/... URI when targeting another user.

Installation

For LangChain retrievers, tools, message history, and context wrappers:

pip install langchain-openviking

For the LangGraph store and middleware:

pip install "langchain-openviking[langgraph]"

Quick start

from langchain_openviking import OpenVikingRetriever
from openviking_sdk import SyncHTTPClient

client = SyncHTTPClient(
    url="http://127.0.0.1:1933",
    api_key="your-user-api-key",
)
client.initialize()
retriever = OpenVikingRetriever(
    client=client,
    target_uri="viking://~/memories",
)

try:
    documents = retriever.invoke("What deployment preferences should I remember?")
finally:
    client.close()

The package also provides OpenVikingSessionRecorder, OpenVikingContextMiddleware, OpenVikingStore, OpenVikingChatMessageHistory, and create_openviking_tools.

Client ownership

• A client supplied through client= or async_client= remains caller-owned.
• Clients created from url= are managed by the adapter and can be closed with close() or aclose() as documented by each adapter.

The previous openviking.integrations.langchain import path remains available from the full openviking distribution as a compatibility shim.

See the OpenViking documentation and the repository's examples/langchain-langgraph directory for complete examples.