# 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, $0.05/call, status unknown (last checked 2026-09-14).

## Facts

- Endpoint: POST https://x402.agentutility.ai/model-selection-brief
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/model-selection-brief-b8ebee39
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FcWMLrfdnn3koemZaAV7M

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 model-selection-brief-b8ebee39 -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
{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "type": "object",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "type": "string",
     "enum": [
      "POST"
     ]
    },
    "bodyType": {
     "type": "string",
     "enum": [
      "json",
      "form-data",
      "text"
     ]
    },
    "body": {
     "properties": {
      "task": {
       "type": "string",
       "description": "Description of the task the model needs to do, e.g. 'summarize customer support tickets'. Required, max 2000 chars."
      },
      "text": {
       "type": "string",
       "description": "Optional representative prompt or sample input. When provided, it is token-counted, compressed, and priced across the recommended (or supplied) models. Max 60,000 chars."
      },
      "constraints": {
       "type": "object",
       "description": "Optional routing constraints: any of latency, budget, context_length, modality (all strings), e.g. { \"budget\": \"cheap\", \"latency\": \"under 1s\" }."
      },
      "models": {
       "type": "array",
       "items": {
        "type": "string"
       },
       "description": "Optional model names to price instead of the routed candidates, e.g. ['deepseek-v3']. Only used when 'text' is also provided."
      }
     },
     "required": [
      "task"
     ]
    }
   },
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "task": {
       "type": "string"
      },
      "route": {
       "type": "object",
       "properties": {
        "recommended_tier": {
         "type": "string"
        },
        "candidate_models": {
         "type": "array",
         "items": {
          "type": "string"
         }
        },
        "reasoning": {
         "type": "string"
        }
       }
      },
      "token_count": {
       "type": "object",
       "properties": {
        "estimated_tokens": {
         "type": "integer"
        }
       }
      },
      "cost_estimate": {
       "type": "object",
       "properties": {
        "input_tokens": {
         "type": "integer"
        },
        "estimates": {
         "type": "array",
         "items": {
          "type": "object",
          "properties": {
 
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "task": "Summarize customer support tickets into a one-line status",
  "route": {
   "reasoning": "Simple summarization does not need a frontier model.",
   "candidate_models": [
    "gpt-4o-mini",
    "claude-haiku-4.5"
   ],
   "recommended_tier": "small"
  },
  "degraded": false,
  "components": [
   {
    "ms": 1100,
    "ok": true,
    "name": "model-route-recommend"
   }
  ],
  "composed_of": [
   "model-route-recommend",
   "llm-cost-estimate",
   "token-count",
   "prompt-compress"
  ],
  "token_count": {
   "estimated_tokens": 500
  },
  "cost_estimate": {
   "estimates": [
    {
     "model": "gpt-4o-mini",
     "total_cost_usd": 0.000075
    }
   ],
   "input_tokens": 500,
   "cheapest_known": "gpt-4o-mini"
  },
  "compressed_prompt": {
   "compressed": "Ticket #4821: checkout button unresponsive, Safari.",
   "actual_ratio": 0.4
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/model-selection-brief-b8ebee39/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)