LangChain
langchain.comframeworkself-hosted
LangChain is a self-hosted framework in the Agent Frameworks layer of the AI stack. Composable abstractions for model calls, tools and state.
By Lattice editorial · Facts verified · method
- licence
- MIT
- language
- Python
- cost
- free
- owned by
- Applied Engineering
Verified 2026-09build refuses it from 2027-04
Use LangChain when
Tool use and state, in an ecosystem where the answers already exist.
Skip LangChain when
You want a thin, legible core — this is a large surface.
Turns a model call into a multi-step program. — that is what this layer of the stack is answerable for. See the full Agent Frameworks section for the rest of the options.
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[](https://lattice.kunjshah.in/agent-frameworks/langchain)Quick answers
- Is LangChain open source?
- Yes. LangChain is open source under the MIT licence. It is free to use.
- What are the alternatives to LangChain?
- The closest alternatives to LangChain are LlamaIndex, Pydantic AI and CrewAI.
Compared in
Reading on agents
Alternatives to LangChain
compare 3 →Listed as an alternative to
- LlamaIndexLlamaIndexData-centric framework for retrieval and agent workflows.Use when Data-centric work where retrieval is the centre of the problem.Skip when You need agent orchestration more than data access.MIT · self-hosted · free
- Pydantic AIPydantic AIType-safe agent framework that leans on Pydantic models.Use when Type-safe agents where schema correctness is the priority.Skip when You want a batteries-included ecosystem.MIT · self-hosted · free
- AutoGenAutoGenMicrosoft research project for conversable multi-agent systems.Use when Research into conversable multi-agent systems.Skip when You need something stable and documented for production.MIT · self-hosted · free
- CrewAICrewAIRole-based orchestration where agents collaborate as a crew.Use when Role-based orchestration where agents are framed as a team.Skip when You want direct control over the loop itself.MIT · self-hosted · free
- Semantic KernelSemantic KernelMicrosoft SDK for embedding AI steps into .NET and Python apps.Use when Embedding AI steps into an existing .NET estate.Skip when Your stack is not .NET.MIT · self-hosted · free
Also in agents
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- Pydantic AIPydantic AIType-safe agent framework that leans on Pydantic models.Use when Type-safe agents where schema correctness is the priority.Skip when You want a batteries-included ecosystem.MIT · self-hosted · free
- AutoGenAutoGenMicrosoft research project for conversable multi-agent systems.Use when Research into conversable multi-agent systems.Skip when You need something stable and documented for production.MIT · self-hosted · free
- CrewAICrewAIRole-based orchestration where agents collaborate as a crew.Use when Role-based orchestration where agents are framed as a team.Skip when You want direct control over the loop itself.MIT · self-hosted · free
- Semantic KernelSemantic KernelMicrosoft SDK for embedding AI steps into .NET and Python apps.Use when Embedding AI steps into an existing .NET estate.Skip when Your stack is not .NET.MIT · self-hosted · free
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