Connect DealScore to ChatGPT
ChatGPT Developer mode can add DealScore as a remote MCP app. The server is Streamable HTTP at https://cardealscore.com/api/mcp. Sign-in is OAuth 2.1 with PKCE, the same email link used on /keys. After you approve access, the chat can call score_deal, explain_grade, and health.
Add the app in Developer mode
Add the server from Developer mode. DealScore has no listing in the public ChatGPT app directory.
- In ChatGPT, open Settings, then Security and login, and turn on Developer mode.
- Add an app and paste the MCP URL below. Do not put an API key in the app. DealScore registers a public OAuth client and uses the email sign-in.
- When ChatGPT asks you to sign in, approve access in the browser.
- In a new chat, give a year, make, model, asking price, and mileage and ask for a grade. ChatGPT should call
score_deal.
Developer mode
https://cardealscore.com/api/mcp
Turn on Developer mode in ChatGPT settings, add an app with this MCP URL, and sign in when asked. Full setup: /integrations/chatgpt.
ChatGPT can read the tool list before sign-in. initialize and tools/list are public methods. Calling score_deal requires the OAuth grant or an API key.
Leave the API key out of the chat
Paste the MCP URL, then sign in. An API key stays on /keys for curl and scripts. The request example is on /used-car-price-api.
If the app does not connect
- Developer mode has to be on before the app can be added.
- The URL is
https://cardealscore.com/api/mcp, with no API key in the app fields. - Finish the browser sign-in when ChatGPT asks. An unfinished consent leaves
score_dealunauthorized. coverage: cannot_scoremeans the connection worked and the comps were too thin to grade.
What the agent can call
score_deal grades a deal. Send asking_price and mileage, plus a VIN or year, make, and model. trim and zip are optional. explain_grade maps a delta_pct to a grade without fetching comps. health reports coverage and limits. Free includes 5 scored calls a month and Builder is $19/mo (founding price) for 1,000 scored calls a month. Only coverage: scored counts, and explain_grade and health are never metered. Plans: /pricing. Argument details: /docs/api. Test arguments in the browser first: /try.
Other clients
Cursor, Claude Code, Claude Desktop, Codex. The REST call and a recorded response are on /used-car-price-api. Every client is also listed on /agents.