> ## Documentation Index
> Fetch the complete documentation index at: https://cndoc-langchain.site/llms.txt
> Use this file to discover all available pages before exploring further.

# 回调集成

> 使用 LangChain JavaScript 进行回调集成。

<Columns cols={3}>
  <Card title="Datadog Tracer" icon="link" href="/oss/javascript/integrations/callbacks/datadog_tracer" arrow="true" cta="查看指南" />

  <Card title="Upstash Rate Limit" icon="link" href="/oss/javascript/integrations/callbacks/upstash_ratelimit_callback" arrow="true" cta="查看指南" />
</Columns>

***

<div className="source-links">
  <Callout icon="terminal-2">
    [通过 MCP 将这些文档](/use-these-docs)连接到 Claude、VSCode 等，以获取实时答案。
  </Callout>

  <Callout icon="edit">
    [在 GitHub 上编辑此页面](https://github.com/langchain-ai/docs/edit/main/src/oss/javascript/integrations/callbacks/index.mdx) 或 [提交问题](https://github.com/langchain-ai/docs/issues/new/choose)。
  </Callout>
</div>