# agentutility — paid x402 endpoints for autonomous agents

> agentutility — paid x402 endpoints for autonomous agents is a paid API for AI agents from x402.agentutility.ai, paid per call via x402, $0.06/call, status unknown (last checked 2026-09-15).

## Facts

- Endpoint: POST https://x402.agentutility.ai/grounded-answer-check
- Price: $0.06/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/grounded-answer-check-0fcec940
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RhtZAVTypkrM021XqAiAZ

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 grounded-answer-check-0fcec940 -d '<json body>'
```

## How this service works

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

## 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": [
      "question"
     ],
     "properties": {
      "context": {
       "type": "string",
       "description": "Optional pre-written answer to GRADE instead of generating a new one via answer-web. Max 4000 chars."
      },
      "question": {
       "type": "string",
       "description": "The question to answer or to grade an answer against. Max 500 chars."
      },
      "strictness": {
       "enum": [
        "lenient",
        "strict"
       ],
       "type": "string",
       "description": "How high the support score must be to mark the answer 'supported'. 'strict' requires stronger evidence coverage. Default 'lenient'."
      }
     }
    },
    "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": {
      "answer": {
       "type": "string"
      },
      "degraded": {
       "type": "boolean"
      },
      "evidence": {
       "type": "array",
       "items": {
        "type": "object",
        "properties": {
         "url": {
          "type": "string"
         },
         "title": {
          "type": "string"
         },
         "supports": {
          "type": "boolean"
         }
        }
       }
      },
      "question": {
       "type": "string"
      },
      "generated": {
       "type": "boolean"
      },
      "grounding": {
       "type": "object",
       "properties": {
        "supported": {
         "type": "boolean"
        },
        "support_score": {
         "type": "integer"
        },
        "unsupported_spans": {
         "type": "array"
        }
       }
      },
      "components": {
       "type": "array",
       "items": {
        "type": "object",
        "properties": {
         "ms": {
          "type": "integer"
         },
         "ok": {
          "type": "boolean"
         },
         "name": 
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "answer": "Paris is the capital of France. It sits on the Seine river.",
  "degraded": false,
  "evidence": [
   {
    "url": "https://example.com/paris",
    "title": "Paris facts",
    "supports": true
   }
  ],
  "question": "What is the capital of France?",
  "generated": true,
  "grounding": {
   "supported": true,
   "support_score": 1,
   "unsupported_spans": []
  },
  "components": [
   {
    "ms": 4200,
    "ok": true,
    "name": "answer-web"
   },
   {
    "ms": 620,
    "ok": true,
    "name": "web-search"
   }
  ],
  "composed_of": [
   "answer-web",
   "web-search",
   "wikipedia-search",
   "retrieval-rerank",
   "citation-verify"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/grounded-answer-check-0fcec940/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)