api-medic

About

api-medic is an HTTP API troubleshooting tool that lives in your browser's DevTools. When an API request misbehaves — fails TLS, returns the wrong content-type, hits a CORS wall, or just runs slowly — open the api-medic panel, pick the request from the captured list, click Analyze, and read a plain-English diagnostic report.

How to use it
1. Open DevTools (F12 or right-click → Inspect).
2. Switch to the "api-medic" tab alongside Network and Console.
3. Reproduce the request — refresh the page, click the broken button, etc. The panel captures it automatically.
4. Select the request, click Analyze, and the diagnostic report appears inline.

What it diagnoses
- TLS handshake failures and certificate issues, including upcoming expiry
- DNS resolution failures
- Redirect loops and excessive redirect chains
- Auth header issues — expired or malformed JWTs, malformed Authorization headers
- Content-type mismatches between request and response
- Slow responses, with a breakdown of where time was spent
- Malformed JSON payloads
- CORS misconfiguration — preflight failures, missing or incorrect headers
- Rate limit responses and Retry-After interpretation
- Body / status-code inconsistencies

Privacy — please read before installing
Analysis runs on a hosted demo server (api-medic.markandrewmarquez.com), not locally in your browser. When you click Analyze, the selected request — URL, headers, bodies, and timing — is sent to that server. The server is stateless: nothing is persisted, no database writes, no logs of request bodies. If you don't want to send captured traffic to an external server, the same analyzer runs as a local web UI and CLI from the GitHub repo.

Open source, MIT licensed
The full source — extension, web UI, CLI, and analysis engine — is at https://github.com/marky224/api-medic. The audience this was originally built for is technical support engineers triaging customer-reported API issues, but the tool is general-purpose: it works on any HTTP(S) request DevTools can see.

Privacy policy: see PRIVACY.md in the repo.
Source: https://github.com/marky224/api-medic