# TLS Certificate Lookup via Certificate Transparency

> TLS Certificate Lookup via Certificate Transparency is a paid API for AI agents from flat-rate-llm.kikoribera03.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Returns all currently valid TLS certificates publicly issued for a domain, read from Certificate Transparency logs, including issuer details, validity windows, days to expiry, revocation status, and covered hostnames.

## Facts

- Endpoint: POST https://flat-rate-llm.kikoribera03.workers.dev/v1/red/cert
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tls-certificate-lookup-via-certificate-transparency-aad9660e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_l1EAS6gw7E7_9Gy0oVYMe

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 tls-certificate-lookup-via-certificate-transparency-aad9660e -d '<json body>'
```

Example prompt: Can you look up all currently valid TLS certificates that have been issued for example.com in the Certificate Transparency logs, including any subdomains, so I can see the issuers, expiry dates, and every hostname they cover?

## When to prefer this

Choose this endpoint when you need to discover what TLS certificates have been publicly issued for a domain — especially to find certificates you didn't provision yourself, enumerate subdomains via CT logs, check expiry timelines, or audit issuers. It reads from Certificate Transparency logs (what was issued), not from a live TLS handshake (what the server serves today), making it ideal for security reconnaissance and shadow-certificate detection. No API key or account needed; pay per call with USDC.

## Known failure modes

- Domain not found in CT logs returns found:false with count:0
- Malformed domain input is coerced from full URLs or emails but invalid strings may return an error
- CT log data may lag by minutes to hours for very recently issued certificates
- Revocation status may not be real-time; relies on CT log publication
- Rate limiting or worker downtime may return 5xx HTTP errors
- Payment failure (402) if USDC balance is insufficient

## How this service works

60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.

## Output

Returns a JSON object with: total certificate count, whether any certificates were found, the queried domain, the data source, details on the current certificate (issuer, validity, days to expiry, revocation status), an array of all issuers found, an array of all hostnames/SANs covered by those certificates, and a list of certificates expiring soon.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "domain"
 ],
 "properties": {
  "domain": {
   "type": "string",
   "description": "The domain to look up. A full URL or an email address is accepted and reduced to its host."
  },
  "subdomains": {
   "type": "boolean",
   "description": "Also return certificates issued for subdomains. Defaults to false."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "count": {
   "type": "number"
  },
  "found": {
   "type": "boolean"
  },
  "domain": {
   "type": "string"
  },
  "source": {
   "type": "string"
  },
  "current": {
   "type": "object"
  },
  "issuers": {
   "type": "array",
   "items": {
    "type": "object"
   }
  },
  "hostnames": {
   "type": "array",
   "items": {
    "type": "object"
   }
  },
  "expiringSoon": {
   "type": "array",
   "items": {
    "type": "object"
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tls-certificate-lookup-via-certificate-transparency-aad9660e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from flat-rate-llm.kikoribera03.workers.dev](https://www.zero.xyz/host/flat-rate-llm.kikoribera03.workers.dev/llms.txt)