> ## Documentation Index
> Fetch the complete documentation index at: https://langchain-5e9cc07a-preview-opensw-1781706951-9d0138e.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Build

> Build agents with LangChain, LangGraph, and Deep Agents using Python.

<div class="home-page mx-auto max-w-8xl px-0 lg:px-5" style={{ paddingBottom: "8rem" }}>
  <div class="mdx-content prose prose-gray dark:prose-invert mx-4 pt-10">
    <h1 class="flex whitespace-pre-wrap group font-semibold text-2xl sm:text-3xl mt-8">Build</h1>

    The LangChain open source stack provides the building blocks you need to design, test, and ship agents in Python.

    <h2 class="flex whitespace-pre-wrap group font-semibold">Choose your starting point</h2>

    Deep Agents, LangChain, and LangGraph share the same stack, so choose based on how much control you need:

    <CardGroup cols={3}>
      <Card title="Deep Agents" cta="Get started" href="/oss/python/deepagents/overview" icon="https://mintcdn.com/langchain-5e9cc07a-preview-opensw-1781706951-9d0138e/5vjJtocmNHh4nqnN/images/brand/deep-agents-icon.png?fit=max&auto=format&n=5vjJtocmNHh4nqnN&q=85&s=96112038f04c526076f496ef737909bf" width="195" height="195" data-path="images/brand/deep-agents-icon.png">
        Build agents for complex, long-running tasks. A complete agent harness with planning, subagents, a virtual filesystem, and long-term memory built in. The fastest way to start.
      </Card>

      <Card title="LangChain" cta="Get started" href="/oss/python/langchain/overview" icon="https://mintcdn.com/langchain-5e9cc07a-preview-opensw-1781706951-9d0138e/5vjJtocmNHh4nqnN/images/brand/langchain-icon.png?fit=max&auto=format&n=5vjJtocmNHh4nqnN&q=85&s=15ed77a517b90eea9fbfd7e9e7bd6b58" width="195" height="195" data-path="images/brand/langchain-icon.png">
        A minimal, configurable agent framework. Compose exactly what you need from models, tools, prompts, and middleware.
      </Card>

      <Card title="LangGraph" cta="Get started" href="/oss/python/langgraph/overview" icon="https://mintcdn.com/langchain-5e9cc07a-preview-opensw-1781706951-9d0138e/5vjJtocmNHh4nqnN/images/brand/langgraph-icon.png?fit=max&auto=format&n=5vjJtocmNHh4nqnN&q=85&s=b10e0dc8b4ddfeb67d0195462bb0c2c4" width="195" height="195" data-path="images/brand/langgraph-icon.png">
        Low-level orchestration for stateful, long-running agents: durable execution, streaming, memory, and human-in-the-loop.
      </Card>
    </CardGroup>

    <h2 class="flex whitespace-pre-wrap group font-semibold">Explore</h2>

    <CardGroup cols={4}>
      <Card title="Integrations" cta="Browse providers" href="/oss/python/integrations/providers/overview" icon="plug">
        Connect to model providers, vector stores, retrievers, and other components.
      </Card>

      <Card title="Learn" cta="View tutorials" href="/oss/python/learn" icon="book">
        Follow tutorials and conceptual guides for common agent patterns and use cases.
      </Card>

      <Card title="Reference" cta="View reference" href="/oss/python/reference/overview" icon="code">
        API references, error codes, release notes, and migration guides.
      </Card>

      <Card title="Contribute" cta="Start contributing" href="/oss/python/contributing/overview" icon="heart-plus">
        Contribute documentation, code, and integrations to the LangChain ecosystem.
      </Card>
    </CardGroup>
  </div>
</div>

***

<div className="source-links">
  <Callout icon="terminal-2">
    [Connect these docs](/use-these-docs) to Claude, VSCode, and more via MCP for real-time answers.
  </Callout>

  <Callout icon="edit">
    [Edit this page on GitHub](https://github.com/langchain-ai/docs/edit/main/src/oss/python/build-overview.mdx) or [file an issue](https://github.com/langchain-ai/docs/issues/new/choose).
  </Callout>
</div>