agentsdir.

LangChain

Last verified: 2026-06-15

Orchestration framework for building agent chains — MCP-native integrations, Python & TypeScript SDKs.

SupervisedCodeLangChainMCP compatible
Try LangChain

LangChain is an open-source orchestration framework for building applications powered by LLM agents, chains, and tool calls. It's for developers who need composable building blocks — prompt templates, memory, retrievers, and agent executors — rather than a fully managed platform. What sets it apart from raw API calls is a large ecosystem of pre-built integrations (vector stores, document loaders, MCP servers) and a standardized agent-executor loop, at the cost of added abstraction overhead.

Pricing

TierPriceNotes
Open source$0Self-hosted, MIT licensed
LangSmith Plus$39/mo per seatObservability & tracing add-on
EnterpriseContact usSSO, dedicated support, on-prem

Best for / Not ideal for

Best for
  • Teams building custom multi-step agent pipelines in Python or TypeScript
  • Projects needing a large library of pre-built retriever/tool integrations
  • Developers who want LangSmith tracing for debugging agent runs
Not ideal for
  • Solo developers who want a minimal, dependency-light agent loop
  • Teams that find the abstraction layer adds more overhead than it saves

Technical specs

LanguagesPython, TypeScript
DeploymentSelf-hosted, LangGraph Platform (managed)
IntegrationsOpenAI, Anthropic, Pinecone, MCP servers

Alternatives to LangChain

LlamaIndex

Data framework for connecting LLM agents to private and structured knowledge sources.

CopilotAPILlamaIndex

CrewAI

Role-based multi-agent orchestration framework for collaborative task automation.

SupervisedCodeCustom

Frequently asked questions

Is LangChain free to use?

Yes, the core LangChain framework is open source and free under the MIT license. LangSmith (observability) has a paid tier starting at $39/month per seat.

What is the best free alternative to LangChain?

LlamaIndex and CrewAI are both open source and free, with lighter abstraction layers for simpler agent pipelines.

Does LangChain support MCP?

Yes, LangChain has native support for Model Context Protocol servers as a tool source for agents.

Can I use LangChain in production?

Yes, LangChain is widely used in production, though many teams pair it with LangGraph for more deterministic control flow at scale.

Does LangChain require Python?

No, LangChain ships official SDKs for both Python and TypeScript/JavaScript.