# AgentUtility Subdomain Enumerator

> AgentUtility Subdomain Enumerator is a paid API for AI agents from x402.agentutility.ai, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-14).

Enumerates subdomains for a given domain, returning a list of discovered hostnames and a count

## Facts

- Endpoint: POST https://x402.agentutility.ai/subdomain-enum
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentutility-subdomain-enumerator-385e8ccf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Fyobtx3K_5fHObyWjjgUA

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 agentutility-subdomain-enumerator-385e8ccf -d '<json body>'
```

Example prompt: Can you enumerate all the subdomains for tesla.com and tell me how many there are?

## When to prefer this

Use this endpoint when an agent needs to programmatically discover the subdomain landscape of a target domain — e.g. for security auditing, attack surface mapping, competitive intelligence, or OSINT. Prefer this over manual DNS brute-force tools when you need a single pay-per-call API with structured JSON output settled in USDC via x402.

## Known failure modes

- Invalid or non-existent domain returns empty subdomain list
- Malformed domain input may return an error response
- Payment failure via x402 results in 402 response before processing
- Rate limiting or timeout for domains with extremely large subdomain spaces
- Private or heavily shielded domains may return incomplete results

## How this service works

Paid x402 endpoints organized into product clusters. USDC-settled on Base. MCP-callable. ERC-8004 identity registry agentId 47167.

## Output

A JSON object containing an array of subdomain objects (each with a 'hostname' field) and a 'subdomain_count' integer indicating how many subdomains were found.

## 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": {
     "required": [
      "domain"
     ],
     "properties": {
      "domain": {
       "type": "string",
       "description": "Target domain to enumerate, e.g. 'example.com'. Normalized (scheme/www stripped)."
      },
      "include_wildcards": {
       "type": "boolean",
       "description": "Include wildcard cert entries (*.sub.example.com). Optional, default false."
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "subdomains": {
       "type": "array",
       "items": {
        "type": "object",
        "properties": {
         "hostname": {
          "type": "string"
         }
        }
       }
      },
      "subdomain_count": {
       "type": "integer"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "subdomains": [
   {
    "hostname": "www.example.com"
   }
  ],
  "subdomain_count": 12
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentutility-subdomain-enumerator-385e8ccf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.agentutility.ai](https://www.zero.xyz/host/x402.agentutility.ai/llms.txt)