GitHub Contribution Chart Generator vs Metabase

This is a keyless JSON API (not an image-rendering service, despite the name) with a single route, `/api/v1/{username}`, that returns a GitHub user's daily/yearly contribution counts — confirmed by inspecting the project's own source tree, which contains only one API file (`src/pages/api/v1/[username].js`); the actual chart image is drawn client-side from that JSON by a separate canvas library. A live unauthenticated GET returned a 200 JSON payload with no `Access-Control-Allow-Origin` header at all, correcting cors from "yes" to "no" (the header only appears on Vercel's default 404 page, not on the real route). Free and open-source, self-hostable on Vercel.

Metabase is a self-hosted (or Metabase Cloud) open-source BI tool whose REST API is documented via an interactive OpenAPI/Scalar reference at `/docs/latest/api`; current docs describe generating an `x-api-key` from Admin settings for programmatic access, correcting auth from "None" to "API Key" (the older session-cookie login flow still exists but keyed API access is now the documented path). Its own `MB_DISABLE_CORS_ON_LOCALHOST` config option (default `false`) confirms the server sends CORS headers by default, consistent with cors "yes". The core server is free and open-source to self-host, with paid Pro, Enterprise, and hosted Cloud tiers layered on top.