> ## Documentation Index
> Fetch the complete documentation index at: https://langchain-5e9cc07a-preview-opensw-1775576783-5997353.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Middleware integrations

> Integrate with middleware using LangChain JavaScript.

Browse available middleware for different providers or contribute your own to the ecosystem. Learn more about how middleware works in the [middleware overview](/oss/javascript/langchain/middleware/overview) and how to use middleware with Deep Agents in the [Deep Agents docs](/oss/javascript/deepagents/customization#middleware).

## Share your middleware

Middleware enables context engineering, harness customization, and runtime safety controls. It is a useful extension point in LangChain and we love highlighting what the community builds with it:

<CardGroup cols={2}>
  <Card title="Add an official integration" icon="package" href="/oss/javascript/contributing/implement-langchain#middleware">
    Follow the contributing guide to build and publish a middleware package.
  </Card>

  <Card title="Share a community middleware" icon="users" href="https://github.com/langchain-ai/docs">
    Open a PR to the docs repo to add your middleware to the table below.
  </Card>
</CardGroup>

## Official integrations

| Provider                                                       | Middleware available |
| -------------------------------------------------------------- | -------------------- |
| [Anthropic](/oss/javascript/integrations/middleware/anthropic) | Prompt caching       |

## Community integrations

Have a middleware to share? [Open a PR](https://github.com/langchain-ai/docs) to add it here.

***

<div className="source-links">
  <Callout icon="edit">
    [Edit this page on GitHub](https://github.com/langchain-ai/docs/edit/main/src/oss/javascript/integrations/middleware/index.mdx) or [file an issue](https://github.com/langchain-ai/docs/issues/new/choose).
  </Callout>

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