# SSL Certificate Transparency Lookup API

> SSL Certificate Transparency Lookup API is a paid API for AI agents from freetier-agent-api.pages.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-30).

Retrieves SSL/TLS certificate information for a given domain from public Certificate Transparency logs, including validity, expiry, issuer, and DNS coverage details.

## Facts

- Endpoint: GET https://freetier-agent-api.pages.dev/api/ssl-cert?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ssl-certificate-transparency-lookup-api-7c3c6cbc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bAHwop_b4yI_kpDXfbEcb

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 ssl-certificate-transparency-lookup-api-7c3c6cbc
```

Example prompt: Can you check the SSL certificate status for stripe.com — I want to know if it's valid, who issued it, and how many days until it expires?

## When to prefer this

Choose this endpoint when you need to programmatically verify SSL/TLS certificate status for a domain without standing up your own CT log integration. It is ideal for agents performing security audits, pre-deployment checks, or monitoring certificate expiry, especially when you want structured JSON output including fingerprint, issuer, DNS coverage, and days-to-expiry in a single call. Prefer this over raw TLS handshake checks when you need historical CT log data rather than the live certificate a server presents.

## Known failure modes

- Domain not found in CT logs — returns empty certs array with has_valid_cert: false
- Invalid or malformed domain input — may return error or empty result
- Domain has no currently valid certificates — valid_count returns 0
- CT log source (SSLMate) temporarily unavailable — request may timeout or return partial data
- Payment failure via x402 — request rejected before processing

## How this service works

Invoice-to-JSON, on-chain tools (transaction explainer + payment check, wallet profile, contract ABI, ERC-20 token risk), company contacts and web-to-RAG for AI agents. Pay per call with x402 (USDC on Base). No signup, no API key.

## Output

Returns a JSON object containing a list of valid certificates from CT logs for the queried domain (newest first), each with issuer name, SHA256 fingerprint, days remaining, DNS names covered, and validity window (not_before/not_after). Also includes summary fields: has_valid_cert (boolean), valid_count, newest_days_left, expiring_within_14d flag, list of unique issuers, data sources used, and the timestamp when the check was performed.

## 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": {
      "domain": {
       "type": "string",
       "description": "exact hostname, e.g. www.example.com"
      }
     }
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "note": {
       "type": [
        "string",
        "null"
       ]
      },
      "certs": {
       "type": "array",
       "items": {
        "type": [
         "object",
         "null"
        ]
       }
      },
      "domain": {
       "type": [
        "string",
        "null"
       ]
      },
      "newest": {
       "type": "object",
       "properties": {
        "issuer": {
         "type": [
          "string",
          "null"
         ]
        },
        "sha256": {
         "type": [
          "string",
          "null"
         ]
        },
        "days_left": {
         "type": [
          "number",
          "null"
         ]
        },
        "dns_names": {
         "type": [
          "array",
          "null"
         ]
        },
        "not_after": {
         "type": [
          "string",
          "null"
         ]
        },
        "not_before": {
         "type": [
          "string",
          "null"
         ]
        },
        "dns_names_total": {
         "type": [
          "number",
          "null"
         ]
        }
       }
      },
      "issuers": {
       "type": "array",
       "items": {
        "type": [
         "string",
         "null"
        ]
       }
      },
      "sources": {
       "type": "array",
       "items": {
        "type": [
         "object",
         "null"
        ]
       }
      },
      "checked_at": {
       "type": [
        "string",
        "null"
       ]
      },
      "valid_count": {
       "type": [
        "number",
        "null"
       ]
      },
      "has_valid_cert": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "newest_days_left": {
     
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "note": "Certificates logged in public Certificate Transparency logs that cover this exact name and are valid now (newest first). The certificate a given server prese...",
  "certs": [
   {
    "issuer": "SSL.com",
    "sha256": "85ca6ab068e9bcce88b6c4aa3c47f7d17228134a457f870d3800e6223a0df07a",
    "days_left": 61,
    "dns_names": [
     "*.example.com",
     "example.com"
    ],
    "not_after": "2026-12-25T22:56:35Z",
    "not_before": "2026-09-26T22:49:11Z",
    "dns_names_total": 2
   },
   {
    "issuer": "SSL.com",
    "sha256": "8355fddfbed74907fff8ad99b4844c3f3a4644261e6f339a12f9f38d56b19502",
    "days_left": 61,
    "dns_names": [
     "*.example.com",
     "example.com"
    ],
    "not_after": "2026-12-25T22:56:35Z",
    "not_before": "2026-09-26T22:48:57Z",
    "dns_names_total": 2
   }
  ],
  "domain": "example.com",
  "newest": {
   "issuer": "SSL.com",
   "sha256": "85ca6ab068e9bcce88b6c4aa3c47f7d17228134a457f870d3800e6223a0df07a",
   "days_left": 61,
   "dns_names": [
    "*.example.com",
    "example.com"
   ],
   "not_after": "2026-12-25T22:56:35Z",
   "not_before": "2026-09-26T22:49:11Z",
   "dns_names_total": 2
  },
  "issuers": [
   "SSL.com",
   "Sectigo"
  ],
  "sources": [
   {
    "url": "https://sslmate.com/ct_search_api/",
    "name": "SSLMate Cert Spotter CT API"
   }
  ],
  "checked_at": "2026-10-25T22:37:38.437Z",
  "valid_count": 13,
  "has_valid_cert": true,
  "newest_days_left": 61,
  "expiring_within_14d": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ssl-certificate-transparency-lookup-api-7c3c6cbc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from freetier-agent-api.pages.dev](https://www.zero.xyz/host/freetier-agent-api.pages.dev/llms.txt)