GitHub ReadMe Stats vs Metabase

GitHub Readme Stats generates SVG stat/language/pin cards for GitHub profile READMEs; its handler explicitly sets `Content-Type: image/svg+xml` and, per its own README, the shared public demo at `github-readme-stats.vercel.app/api` is "best-effort and can be unreliable due to rate limits and traffic spikes" (confirmed today: it returned a `DEPLOYMENT_PAUSED` 503) — the project itself is very much alive (58k+ GitHub stars, commits within the last week) and explicitly recommends self-hosting or a GitHub Actions workflow instead of relying on the shared instance. Neither the Vercel serverless handlers nor Vercel's platform add a CORS header by default, correcting cors from "yes" to "no". Free and open-source, self-hostable.

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.