> ## 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>
</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 **Apps**). You need **Developer Mode** enabled — available on Plus, Pro, Team, Enterprise, and Edu plans.

<Steps>
  <Step title="Enable Developer Mode">
    In ChatGPT, open **Settings → Apps & connectors → Advanced** and turn on **Developer Mode**.
  </Step>

  <Step title="Create a connector">
    Go to **Connectors** (or **Apps**) and click **Create** (or **Add custom connector**).
  </Step>

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

  <Step title="Authenticate">
    Choose one of the following:

    * **API key** — paste your Terrapin API key. This is the simplest option.
    * **OAuth** — select OAuth as the authentication method. When ChatGPT redirects you to authorize the connection, sign in to your Terrapin account. If prompted for an OAuth client secret during setup, use your Terrapin API key.
  </Step>

  <Step title="Save and verify">
    Click **Create** (or **Save**). ChatGPT calls `tools/list` and shows the available Terrapin tools. Enable the connector in a new chat via the tool picker.
  </Step>
</Steps>

## 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.