---
title: "Inspect a TLS certificate (issuer, validity, fingerprint, alt names, chain)"
method: POST
path: "/ssl-check.php"
tags: ["data"]
---

# Inspect a TLS certificate (issuer, validity, fingerprint, alt names, chain)

`POST /ssl-check.php`

## Request

- Base URL: `https://mate.tools/api/v1`
- URL: `https://mate.tools/api/v1/ssl-check.php`
- Auth: none declared

Connects to {domain}:{port} over TLS and inspects the leaf certificate plus the full chain the server presents. Returns subject, issuer, validity dates, days remaining until expiry, alt names, signature algorithm, serial, SHA-256 fingerprint, negotiated protocol and cipher. SSRF-protected: refuses to connect if the host resolves to a private/loopback/link-local/cloud-metadata IP. 5s connect timeout.

## Request body

- object
  - `domain` string, required: Hostname only - no scheme, no path. e.g. example.com
  - `port` integer

## Response `200`

Success

## Other responses

- `400`: Malformed request
- `429`: Rate limit exceeded (60/min, 600/hour per IP). Includes Retry-After header.
- `502`: TLS handshake failed (connection refused, timeout, etc.)

---

[API](https://skmtc.dev/mate/apis/mate-tools-api.md) · [All operations](https://skmtc.dev/mate/apis/mate-tools-api/llms.txt) · [OpenAPI document](https://skmtc.dev/mate/apis/mate-tools-api/revisions/874670b78962?raw)