# TLS Certificate Inspector

> TLS Certificate Inspector is a paid API for AI agents from tls.openverbs.com, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-14).

Opens a TLS connection to a given hostname and returns its certificate details: issuer, subject, validity window, days remaining, SANs, fingerprint, and trust status.

## Facts

- Endpoint: POST https://tls.openverbs.com/v1/inspect
- Price: $0.006/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-inspector-b317172d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ffPXrbxCM5C-0n6_La7bh

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-inspector-b317172d -d '<json body>'
```

Example prompt: Can you inspect the TLS certificate for api.mycompany.com on port 443 and tell me who issued it, when it expires, and how many days are left?

## When to prefer this

Use this endpoint when you need to programmatically retrieve raw TLS certificate details — expiry, issuer, SANs, fingerprint, and trust status — for any hostname, including non-standard ports or custom SNI names. Prefer this over generic HTTPS-check tools when you need structured certificate metadata rather than just a pass/fail status.

## Known failure modes

- Host unreachable or connection refused — returns error indicating the host could not be connected to
- TLS handshake failure — if the server does not support TLS or the handshake fails
- Invalid hostname format — if the host field is empty or malformed
- Port out of range — if port is not between 1 and 65535
- Self-signed or untrusted certificate — returned in trust status field rather than as an error
- SNI mismatch — cert returned may not match the servername if misconfigured

## How this service works

Open a TLS connection to a host and report its certificate — issuer, subject, validity window, days remaining, SANs, fingerprint and trust status.

## Output

Returns TLS certificate metadata for the given host, including the issuer (CA), subject (domain name), validity window (not-before and not-after dates), days remaining until expiry, Subject Alternative Names (SANs), certificate fingerprint, and trust status indicating whether the cert chains to a trusted root.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "host"
     ],
     "properties": {
      "host": {
       "type": "string",
       "maxLength": 253,
       "minLength": 1,
       "description": "Hostname to connect to, e.g. \"github.com\"."
      },
      "port": {
       "type": "integer",
       "maximum": 65535,
       "minimum": 1,
       "description": "TLS port. Defaults to 443."
      },
      "servername": {
       "type": "string",
       "description": "SNI server name, if different from host."
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tls-certificate-inspector-b317172d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tls.openverbs.com](https://www.zero.xyz/host/tls.openverbs.com/llms.txt)