Register for an API account at carmd.com and retrieve your API key and partner token from the developer dashboard
All requests require both an Authorization header with a Base64-encoded key and a partner-token header; construct these from your credentials before making any API call
Decode a VIN's basic info by calling GET http://api.carmd.com/v3.0/decode?vin=<VIN> to verify the vehicle is recognized before requesting diagnostic data
To check maintenance needs or predicted repairs, call GET /v3.0/maintlist?vin=<VIN>&mileage=<odometer> — the mileage parameter is required for maintenance schedule lookups
For OBD-II trouble code lookups, call GET /v3.0/repair?vin=<VIN>&dtc=<code> to retrieve repair information, estimated cost, and common fixes associated with that DTC on that specific vehicle
Known gotchas
CarMD API responses vary in completeness by vehicle age and make; older or less common vehicles may return limited or no repair data even for common DTCs — always handle empty or null repair arrays gracefully
The free tier has a low monthly request cap; plan API call volume carefully and cache responses for repeated VIN or DTC lookups since the underlying data changes infrequently
The API uses HTTP (non-TLS) endpoints in some documentation examples; always use HTTPS in production to protect the VIN and any user data in transit
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp