api-medic

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