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

# MCP access

> Connect Terrapin to Claude or ChatGPT via the Model Context Protocol.

The Terrapin API is available as a [Model Context Protocol](https://modelcontextprotocol.io) (MCP) server. Once connected, Claude or ChatGPT can call every API endpoint as a tool (bond search, pricing, documents, and more) without you writing any integration code.

Every MCP request uses the same [API key](/authentication) as a direct HTTP call. Requests count against your [rate limits and quotas](/rate-limits-and-quotas) the same way.

**MCP server URL:** `https://terrapinfinance.com/mcp`

## Claude

<Steps>
  <Step title="Open Connectors">
    In [claude.ai](https://claude.ai), click **Customize** in the top-right corner of the chat window, then click **Connectors**.
  </Step>

  <Step title="Add a custom connector">
    Click the **+** button and select **Add custom connector**.
  </Step>

  <Step title="Fill in the connector details">
    * **Name:** `Terrapin`
    * **URL:** `https://terrapinfinance.com/mcp`
  </Step>

  <Step title="Add your API key">
    Expand **Advanced settings** and paste your Terrapin API key into the **OAuth Client Secret** field. The **OAuth Client ID** field accepts any non-empty string.
  </Step>

  <Step title="Save">
    Click **Add**. The Terrapin connector appears under your web connectors and can be toggled on per conversation.
  </Step>

  <Step title="Allow terrapinfinance.com (sandboxed environments only)">
    If Claude runs in a container or an agent sandbox with a domain allowlist, add `terrapinfinance.com` as described in [Network access](/mcp/network-access). Skip this on an ordinary network.
  </Step>
</Steps>

<Note>
  Claude's custom connector UI requires OAuth credentials even though Terrapin authenticates with a bearer token. We map the OAuth client credentials flow onto your existing API key: the client secret you paste is used directly as the bearer token on every MCP request.
</Note>

## ChatGPT

ChatGPT connects to remote MCP servers as custom connectors (also called **Plugins**). You need **Developer Mode** enabled, which is available on Plus, Business, Enterprise, and Edu plans.

<Steps>
  <Step title="Add a plugin">
    In [ChatGPT](https://chatgpt.com/), open Settings → Plugins → Add → **Add custom MCP server**
  </Step>

  <Step title="Fill in the plugin details">
    * **Name:** `Terrapin`
    * **Connection URL:** `https://terrapinfinance.com/mcp`
  </Step>

  <Step title="Add your API key">
    Expand **Advanced OAuth settings** and paste your Terrapin API key into the
    **OAuth Client Secret** field. The **OAuth Client ID** field accepts any
    non-empty string, for example `Terrapin`.
  </Step>

  <Step title="Sign in and verify">
    Click **Create as plugin**. When ChatGPT redirects you to authorize the
    connection, sign in to your Terrapin account. ChatGPT then calls
    `tools/list` and shows the available Terrapin tools. Enable the plugin in a
    new chat via the tool picker.
  </Step>
</Steps>

Running in a container, an agent sandbox, or behind a corporate proxy? See [Network access](/mcp/network-access) for the host to allow, or the assistant will find documents it cannot open.

## Example prompts

Once connected, you can ask things like:

* *"Search for general obligation bonds from California issued after 2020"*
* *"Get the latest pricing for CUSIP 912810TM0"*
* *"Retrieve the official statement for ISIN US3733832070"*

The assistant calls the matching Terrapin API endpoints and returns the results in the conversation.


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