Chat Langchain
Freelocally hosted chatbot specifically focused on question answering over the LangChain documentation 
FreeFree tier
Inputs: textOutputs: text
About Chat Langchain
Chat LangChain is an open-source documentation assistant agent that answers questions about LangChain, LangGraph, and LangSmith. It demonstrates a production-ready agent architecture using Managed Deep Agents, LangChain Agents, and guardrails. Features include documentation search via MCP, support knowledge base search via Pylon, link validation, and off-topic query filtering. The repository provides a Next.js frontend and supports local or managed deployment.
Key Features
Documentation search via managed MCP connector
Support KB search using Pylon for known issues
Link validation before including URLs in responses
Guardrails to filter off-topic queries
Managed Deep Agent deployment with identity and connectors
Next.js frontend for public chat UI
Configurable model (Anthropic API key example)
Supports local development with uv or pip
Pros & Cons
Pros
- Open source and free to use
- Modular architecture with managed deployment options
- Integrates official docs and support KB for accurate answers
- Includes guardrails to maintain topic relevance
- Active development under langchain-ai organization
Cons
- Limited to LangChain ecosystem (LangChain, LangGraph, LangSmith)
- Requires setup of API keys (e.g., Anthropic, Pylon) and environment configuration
- Not a general-purpose chatbot; focused strictly on LangChain documentation
- Documentation on running locally may require familiarity with Python and Next.js
Best For
Answering questions about LangChain documentationTroubleshooting known issues from support knowledge baseValidating URLs before providing them in answersKeeping conversations on-topic with guardrails
FAQ
What is Chat LangChain?
It is an open-source documentation assistant agent that answers questions about LangChain, LangGraph, and LangSmith, using a managed agent architecture.
How do I run Chat LangChain locally?
Clone the repository, install dependencies with uv or pip, copy the .env.example to .env and fill in required API keys (e.g., ANTHROPIC_API_KEY), then run 'uv run mda dev .' for the backend and 'npm ci && npm run dev:local' for the frontend.
What are the prerequisites?
Python 3.11+ and either uv (recommended) or pip. For the frontend, Node.js and npm are needed.
Does Chat LangChain guard against off-topic queries?
Yes, it includes guardrails middleware that checks if the query is related to LangChain before processing.