# ssl.sh developer docs: curl, JSON API and MCP server

> Check TLS certificates from the terminal with curl, from code with the JSON API, or from AI assistants through the ssl.sh MCP server.

Source: https://ssl.sh/docs/
Last updated: 2026-11-10

ssl.sh offers the same certificate checker through three developer interfaces:

- **[Command line](devdoc:cli)**: `curl ssl.sh/example.com` prints a colored summary; `/days`, `/chain` and `/json` give script-friendly output.
- **[JSON API](devdoc:api)**: `GET /api/v1/check`, `chain`, `ct`, `caa`, `hsts`, `mixed-content` and `POST /api/v1/decode`.
- **[MCP server](devdoc:mcp)**: `https://ssl.sh/mcp` lets Claude, Cursor and other MCP clients check certificates, search CT logs and explain SSL errors.

All three share one engine: it connects to the host, reads the certificate chain the server actually sends, verifies it against the Mozilla root store, fills in missing intermediates via AIA, and grades the result.