# X402 Host Inspector

> X402 Host Inspector is a paid API for AI agents from x402.feld-feder.at, paid per call via x402, $0.005/call, status down (last checked 2026-09-15).

Inspects a target URL's DNS resolution, TLS certificate, and HTTP reachability in a single pay-per-request call.

## Facts

- Endpoint: POST https://x402.feld-feder.at/v1/host/inspect
- Price: $0.005/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-host-inspector-a6c88845
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PNVNyqoFgdwG_oacdekds

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 x402-host-inspector-a6c88845 -d '<json body>'
```

Example prompt: Can you inspect the host at https://api.myservice.com — I need to see its DNS resolution, TLS certificate details, and whether HTTP is reachable?

## When to prefer this

Choose this endpoint when you need a combined DNS + TLS + HTTP probe in a single call without setting up your own infrastructure. Ideal for AI agents that need to validate external hosts, audit certificates, or diagnose connectivity issues on-demand with micropayment billing (no subscription required). Prefer over manual curl/dig workflows when the agent needs structured, machine-readable output about a host's network posture.

## Known failure modes

- Invalid or unreachable URL returns null for TLS and HTTP fields with warnings populated
- Malformed URL input fails schema validation before reaching the network
- DNS resolution failure results in empty addresses array and warnings
- TLS handshake failure returns null tls field with warning details
- Payment of 0.005 USDC not provided causes HTTP 402 rejection before inspection runs
- URL exceeding 4096 characters rejected by schema validation

## How this service works

Pay-per-request data tools for AI agents.

## Output

Returns a structured JSON object containing: the resolved DNS hostname, port, and IP addresses; TLS details including protocol version, cipher suite, ALPN protocol, peer address, and full certificate info (subject, issuer, serial number, validity dates, SANs); HTTP response details; and a list of any warnings encountered during inspection.

## 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",
     "title": "WebUrlRequest",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "title": "Url",
       "maxLength": 4096,
       "minLength": 1
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "ResponseEnvelope[HostInspectionResult]",
     "required": [
      "data"
     ],
     "properties": {
      "ok": {
       "type": "boolean",
       "const": true,
       "title": "Ok",
       "default": true
      },
      "data": {
       "type": "object",
       "title": "HostInspectionResult",
       "required": [
        "target_url",
        "dns",
        "tls",
        "http",
        "warnings"
       ],
       "properties": {
        "dns": {
         "type": "object",
         "title": "HostDnsResult",
         "required": [
          "hostname",
          "port",
          "addresses"
         ],
         "properties": {
          "port": {
           "type": "integer",
           "title": "Port",
           "maximum": 65535,
           "minimum": 1
          },
          "hostname": {
           "type": "string",
           "title": "Hostname"
          },
          "addresses": {
           "type": "array",
           "items": {
            "type": "string"
           },
           "title": "Addresses"
          }
         },
         "additionalProperties": false
        },
        "tls": {
         "anyOf": [
          {
           "type": "object",
           "title": "HostTlsResult",
           "required": [
            "protocol",
            "cipher",
            "alpn_protocol",
            "peer_address",
            "certificate"
           ],
           "properties": {
            
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "data": {
   "dns": {
    "port": 443,
    "hostname": "example.com",
    "addresses": [
     "93.184.216.34"
    ]
   },
   "tls": null,
   "http": null,
   "warnings": [],
   "target_url": "https://example.com"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-host-inspector-a6c88845/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.feld-feder.at](https://www.zero.xyz/host/x402.feld-feder.at/llms.txt)