# mm-agent-utils x402 Endpoint Linter

> mm-agent-utils x402 Endpoint Linter is a paid API for AI agents from mm-agent-utils.gferrigno.deno.net, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-10).

Lints and validates an x402-enabled HTTP endpoint, checking its payment offers, compliance, and configuration correctness.

## Facts

- Endpoint: GET https://mm-agent-utils.gferrigno.deno.net/v1/x402-check?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mm-agent-utils-x402-endpoint-linter-3cd25bc9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yY7TQVPOhRsebrJuYrinc

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 mm-agent-utils-x402-endpoint-linter-3cd25bc9
```

Example prompt: Can you lint my x402 endpoint at https://my-api.example.com/paid-data and tell me if the payment offers and configuration look correct?

## When to prefer this

Use this endpoint when you need to programmatically verify that a specific URL is a correctly configured x402 pay-per-call endpoint — especially before integrating it into an agent workflow, debugging payment failures, or auditing third-party x402 APIs for correctness. Prefer it over manual inspection when you need structured output including offer details, warnings, and a machine-readable verdict.

## Known failure modes

- Target URL is not reachable or times out
- Target URL does not return a 402 status (not an x402 endpoint)
- Malformed or missing x402 payment headers result in warnings or error verdict
- Non-HTTPS URLs rejected by input schema
- Invalid or missing 'url' query parameter returns validation error

## How this service works

Tiny pay-per-call utilities for agents on Base: wallet vetting, x402 endpoint linting, deterministic entity extraction.

## Output

Returns a JSON object containing the linted endpoint URL, an array of payment offers (each with pay_to address, network, USDC price, and asset symbol), a verdict ('ok' or error), any warnings, the HTTP status code, and the x402 protocol version detected.

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "https URL of the x402 endpoint to lint"
      },
      "method": {
       "type": "string",
       "description": "GET (default) or POST"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://example.com/paid-endpoint",
  "offers": [
   {
    "pay_to": "0x...",
    "network": "eip155:8453",
    "price_usdc": "0.01",
    "asset_symbol": "USDC"
   }
  ],
  "verdict": "ok",
  "warnings": [],
  "http_status": 402,
  "x402_version": 2
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mm-agent-utils-x402-endpoint-linter-3cd25bc9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mm-agent-utils.gferrigno.deno.net](https://www.zero.xyz/host/mm-agent-utils.gferrigno.deno.net/llms.txt)