# SiteCheck Certificate Transparency Lookup

> SiteCheck Certificate Transparency Lookup is a paid API for AI agents from api.healthtravel-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).

Retrieves SSL/TLS certificate transparency records for a domain from crt.sh/Certspotter, returning certificate details including validity periods, DNS names, and SHA-256 hashes.

## Facts

- Endpoint: GET https://api.healthtravel-api.workers.dev/api/travel/crtsh-certificate-transparency?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-certificate-transparency-lookup-4cc74a36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_F-5Yf-YVvmNe0WpdqDDyw

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability sitecheck-certificate-transparency-lookup-4cc74a36
```

Example prompt: Can you pull the certificate transparency records for example.com from crt.sh and show me up to 20 certificates, including their validity dates and which DNS names they cover?

## When to prefer this

Choose this endpoint when you need to query certificate transparency logs for a specific domain without setting up an API key or account with Certspotter/crt.sh directly. Ideal for one-off or infrequent certificate lookups in agent workflows where pay-per-call is preferred over a subscription. Useful for security audits, subdomain enumeration via CT logs, and verifying certificate integrity. Prefer this over direct crt.sh web scraping when you need structured JSON output with consistent schema.

## Known failure modes

- Invalid domain format returns an error (domain must use letters, digits, dots, hyphens only)
- limit parameter out of range (must be 1–50) may return an error or be clamped
- Domain not found in CT logs returns an empty certificates array with count 0
- Upstream Certspotter API unavailability causes a 5xx error; no charge on failed calls
- Rate limiting by upstream provider may result in delayed or empty responses

## How this service works

Certificate transparency records for a domain from the CertSpotter public CT index: certificate id, validity dates, revocation flag and the DNS names on each certificate (including subdomains). Shows issued certificates only, not live TLS configuration. crt.sh was unavailable during testing, so CertSpotter is used.

## Output

Returns a JSON object with the queried domain, a count of certificates found, the Certspotter API source URL, a timestamp of when the check was performed, and an array of certificate records each containing: certificate ID, revocation status, list of DNS names covered, notBefore/notAfter validity dates, and the SHA-256 certificate fingerprint.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "domain"
     ],
     "properties": {
      "limit": {
       "type": "string",
       "description": "Max certificates, 1 to 50 (default 10)"
      },
      "domain": {
       "type": "string",
       "description": "Domain name, e.g. wikivoyage.org (letters, digits, dots, hyphens)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 3,
  "domain": "wikivoyage.org",
  "source": "https://api.certspotter.com/v1/issuances",
  "checkedAt": "2026-10-23T09:36:41.317Z",
  "certificates": [
   {
    "id": "16313322805",
    "revoked": false,
    "dnsNames": [
     "*.m.mediawiki.org",
     "*.m.wikibooks.org"
    ],
    "notAfter": "2026-11-03T19:15:40Z",
    "notBefore": "2026-08-05T19:15:41Z",
    "certSha256": "08e0b65df41fb075ec91c1dcd2cacc4e8c7dda53b754806525117b32f7b73253"
   },
   {
    "id": "17388610453",
    "revoked": false,
    "dnsNames": [
     "*.m.mediawiki.org",
     "*.m.wikibooks.org"
    ],
    "notAfter": "2026-12-23T14:37:36Z",
    "notBefore": "2026-09-24T14:37:37Z",
    "certSha256": "9908b07ed23df45f6bd5023880863a3d023db2a4748763defed536e3162a32d2"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-certificate-transparency-lookup-4cc74a36/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.healthtravel-api.workers.dev](https://www.zero.xyz/host/api.healthtravel-api.workers.dev/llms.txt)