SSL Certificate Check Skill

Overview

An SSL checker API and certificate verification API for expiry monitoring, domain audits and CI checks: send a hostname, get its live SSL certificate back as JSON. SSL Checker opens a real TLS connection to the site, reads the certificate and the chain the server sends, and validates it the way a client does (trusted root, hostname match, expiry), returning the verifier's error code such as CERT_HAS_EXPIRED or UNABLE_TO_VERIFY_LEAF_SIGNATURE when it fails. Alongside issuer, subject, key type, key size and signature algorithm, it reports the TLS protocol and cipher negotiated, the Strict-Transport-Security policy, OCSP stapling and embedded Certificate Transparency SCTs, plus derived checks: days until expiry, an expiring-soon flag and self-signed detection. To see which TLS versions a server still accepts, pair it with TLS Checker.

Live Test SSL Certificate Check Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as SSLCertificateCheckSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

{
  "name": "SSLCertificateCheckSkill",
  "arguments": {
    "domain": "ebay.com"
  }
}

You do not name the tool yourself; the model picks it. Asking about ebay.com in the terms this skill covers is enough for it to reach for SSLCertificateCheckSkill on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

https://api.vervekit.com/v1/mcp

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

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{
  "status": "ok",
  "error": null,
  "data": {
    "subject": {
      "C": "US",
      "ST": "California",
      "O": "eBay, Inc.",
      "CN": "ebay.com"
    },
    "issuer": {
      "C": "GB",
      "O": "Sectigo Limited",
      "CN": "Sectigo Public Server Authentication CA OV R40"
    },
    "subjectaltname": "DNS:ebay.com, DNS:befr.ebay.be, DNS:benl.ebay.be, DNS:cafr.ebay.ca, DNS:e-bay.com, DNS:e-bay.it, DNS:ebay.at, DNS:ebay.be, DNS:ebay.ca, DNS:ebay.ch, DNS:ebay.co.nz, DNS:ebay.co.uk, DNS:ebay.com.au, DNS:ebay.com.cn, DNS:ebay.com.hk, DNS:ebay.com.my, DNS:ebay.com.ph, DNS:ebay.com.sg, DNS:ebay.de, DNS:ebay.es, DNS:ebay.fr, DNS:ebay.ie, DNS:ebay.in, DNS:ebay.io, DNS:ebay.it, DNS:ebay.nl, DNS:ebay.ph, DNS:ebay.pl, DNS:ebay.us, DNS:ebay.vn, DNS:shorturiweb.ebay.com, DNS:wwww.ebay.co.uk, DNS:wwww.ebay.com, DNS:wwww.ebay.com.au, DNS:wwww.ebay.de, DNS:wwww.ebay.in, DNS:wwww.ebay.it",
    "infoAccess": {
      "CA Issuers - URI": [
        "http://crt.sectigo.com/SectigoPublicServerAuthenticationCAOVR40.crt"
      ],
      "OCSP - URI": [
        "http://ocsp.sectigo.com"
      ]
    },
    "ca": false,
    "bits": 2048,
    "valid_from": "Oct  6 00:00:00 2026 GMT",
    "valid_to": "Apr 22 23:59:59 2027 GMT",
    "serialNumber": "19FD41E42C169CF248511D2BEE660A83",
    "domain": "ebay.com",
    "isExpired": false,
    "isValid": true,
    "daysUntilExpiry": 182,
    "isExpiringSoon": false,
    "isSelfSigned": false,
    "protocol": "TLSv1.3",
    "cipher": "TLS_AES_128_GCM_SHA256",
    "isTrusted": true,
    "trustError": null,
    "hostnameMatches": true,
    "chain": [
      {
        "subject": "ebay.com",
        "issuer": "Sectigo Public Server Authentication CA OV R40",
        "validTo": "Apr 22 23:59:59 2027 GMT",
        "isCA": false
      },
      {
        "subject": "Sectigo Public Server Authentication CA OV R40",
        "issuer": "Sectigo Public Server Authentication Root R46",
        "validTo": "May 13 23:59:59 2040 GMT",
        "isCA": true
      },
      {
        "subject": "Sectigo Public Server Authentication Root R46",
        "issuer": "USERTrust RSA Certification Authority",
        "validTo": "Jan 18 23:59:59 2038 GMT",
        "isCA": true
      },
      {
        "subject": "USERTrust RSA Certification Authority",
        "issuer": "USERTrust RSA Certification Authority",
        "validTo": "Jan 18 23:59:59 2038 GMT",
        "isCA": true
      }
    ],
    "keyType": "RSA",
    "signatureAlgorithm": "sha256WithRSAEncryption",
    "hasEmbeddedSCTs": true,
    "ocspStapled": true,
    "hsts": {
      "present": true,
      "maxAge": 31536000,
      "includeSubDomains": false,
      "preload": false
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

A call costs 10 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

SSL Monitoring and Expiry Alerts

DevOps teams check their domains daily from a cron job or uptime monitor, alerting on certificates close to expiry, failed chain validation or a hostname mismatch before browsers start showing warnings.

Customer Domain Audits

When clients point custom hostnames to a SaaS platform, automated onboarding scripts verify validity status and key strength before activating traffic.

Certificate Chain and Key Audits

Security teams sweep corporate web properties for setups that need fixing: certificates that fail validation, servers missing an intermediate, RSA keys under 2048 bits, SHA-1 signatures or no HSTS policy.

Partner Domain Verification

To prevent broken checkouts, e-commerce marketplaces inspect partner payment gateways to confirm validity windows before routing shopper transactions.

Other ways to use SSL Certificate Check Skill

Set up SSL Certificate Check Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

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