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Check a certificate

mttr_ssl_checkAny key

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What does mttr_ssl_check do?

Checks one public host’s SSL certificate with a single TLS handshake: whether it is valid for the name, who issued it, the days left, the chain as sent and whether it verifies, the TLS version agreed, whether TLS 1.0 and 1.1 are still let in, and whether http:// moves to https:// with HSTS. Any key may make this call, on any public site.

When to use it

  • Before a certificate expires, or after it was renewed, to see the new one is served.
  • A browser, a crawler or an app refuses the site and you want to know why.

What you ask

You say“Is the certificate on example.com valid, and when does it expire?”

Your assistant calls
mttr_ssl_check({
  host: "host"
})
ArgumentTypeNeededWhat it is
hostTextYesThe host to check, such as example.com or www.example.com. A full address is taken too, and only its host is used.

What comes back

  • Each finding with its state in a word, and what to do when something is wrong.
  • The certificate: names it covers, issuer, dates, key and signature.
  • The chain as sent, and the version and cipher agreed.
  • Only the handshake is sent on port 443; public addresses only.
What it answersSample
CheckStateWhat it means
NameMatchesThe certificate names example.com
DatesExpires soonRenew it within 18 days
ChainTrustedIt verifies to a trusted root
TLS 1.0 and 1.1RefusedAs they should be

Made-up sites and figures, to show the shape of the answer. The answer itself is JSON.

Over HTTP

It is GET /api/v1/check/ssl, with your key as a bearer token:

HTTP
curl "https://mttr.si/api/v1/check/ssl?host=host" \
  -H "Authorization: Bearer $MTTR_KEY"

When it fails

WhenStatusWhat to do
Your assistant has no key yet401 over MCPSign up with mttr_signup, then connect again with the key it gives.
The key has used this hour’s free checks429The answer says ssl checks are limited to an hourly allowance. Try again within the hour.

Every error’s wording is in the API reference.

The call in full, with its HTTP address, each argument’s type, who may make it and the call in four languages, is mttr_ssl_check in the API reference.

Goes with

Sources