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The Terrapin API is available as a Model Context Protocol (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 as a direct HTTP call. Requests count against your rate limits and quotas the same way. MCP server URL: https://terrapinfinance.com/mcp

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Claude

1

Open Connectors

In claude.ai, click Customize in the top-right corner of the chat window, then click Connectors.
2

Add a custom connector

Click the + button and select Add custom connector.
3

Fill in the connector details

  • Name: Terrapin
  • URL: https://terrapinfinance.com/mcp
4

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.
5

Save

Click Add. The Terrapin connector appears under your web connectors and can be toggled on per conversation.
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.

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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.
1

Enable Developer Mode

In ChatGPT, open Settings → Apps & connectors → Advanced and turn on Developer Mode.
2

Create a connector

Go to Connectors (or Apps) and click Create (or Add custom connector).
3

Fill in the connector details

  • Name: Terrapin
  • MCP server URL: https://terrapinfinance.com/mcp
4

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.
5

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.

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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.