> ## Documentation Index
> Fetch the complete documentation index at: https://nango.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Circleback (MCP)

> Integrate your application with the Circleback MCP API

## 🚀 Quickstart

Connect to Circleback (MCP) with Nango and start calling tools in minutes. Circleback MCP uses OAuth 2.0 with dynamic client registration, meaning no app registration is required.

<Steps>
  <Step title="Create the integration">
    In Nango ([free signup](https://app.nango.dev)), go to [Integrations](https://app.nango.dev/dev/integrations) -> *Configure New Integration* -> *Circleback (MCP)*.
  </Step>

  <Step title="Authorize Circleback">
    Go to [Connections](https://app.nango.dev/dev/connections) -> *Add Test Connection* -> *Authorize*, then log in to Circleback. Later, you'll let your users do the same directly from your app.
  </Step>

  <Step title="Call the Circleback MCP API">
    Make your first MCP request (e.g. list available tools). Replace the placeholders below with your [secret key](https://app.nango.dev/dev/environment-settings), [integration ID](https://app.nango.dev/dev/integrations), and [connection ID](https://app.nango.dev/dev/connections):

    <Tabs>
      <Tab title="cURL">
        ```bash theme={null}
        curl "https://api.nango.dev/mcp" \
          -X POST \
          -H "Authorization: Bearer <NANGO-SECRET-KEY>" \
          -H "Provider-Config-Key: <INTEGRATION-ID>" \
          -H "Connection-Id: <CONNECTION-ID>" \
          -H "Content-Type: application/json" \
          -d '{
            "jsonrpc": "2.0",
            "id": 2,
            "method": "tools/list",
            "params": {}
        }'
        ```
      </Tab>

      <Tab title="Node">
        Install Nango's backend SDK with `npm i @nangohq/node`. Then run:

        ```typescript theme={null}
        import { Nango } from '@nangohq/node';

        const nango = new Nango({ secretKey: '<NANGO-SECRET-KEY>' });

        const res = await nango.post({
            endpoint: '/api/mcp',
            providerConfigKey: '<INTEGRATION-ID>',
            connectionId: '<CONNECTION-ID>',
            body: {
                jsonrpc: '2.0',
                id: 2,
                method: 'tools/list',
                params: {}
            }
        });

        console.log(res.data);
        ```
      </Tab>
    </Tabs>

    ✅ You're connected! Check the [Logs](https://app.nango.dev/dev/logs) tab in Nango to inspect requests.
  </Step>

  <Step title="Implement Nango in your app">
    Follow our [Auth implementation guide](/guides/primitives/auth) to integrate Nango in your app.
  </Step>
</Steps>

## 📚 Circleback (MCP) Integration Guides

Nango uses **dynamic client registration** with Circleback's OAuth server. You do not need to register an MCP application, just create the integration in Nango and authorize with your Circleback account.

Official docs: [Circleback MCP](https://support.circleback.ai/en/articles/13249081-circleback-mcp)

***