Lint an x402 endpoint before agents find it broken
Lint an x402 endpoint before agents find it broken. Probes a third-party 402 (unpaid, SSRF-checked) and audits it: description ≥450 chars (CDP silently rejects at settle → 402 {} with no charge), missing Bazaar discovery or input/output schemas, resource.url host mismatch or *.workers.dev identity, x402Version 1 (frozen), non-CAIP-2 network, unparseable amount, unknown asset, odd maxTimeoutSeconds. Returns pass/warn/fail/info checks + summary.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
5453 msmedian answer time
$0.003listed price per call
$0.003price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://staging.402utils.com/v1/x402-lint
| Category | Code and developer |
|---|---|
| Provider host | staging.402utils.com |
| Networks | eip155:84532 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.003 | 5453 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"url": "https://402utils.com/v1/rss-to-json"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"description": "Query string only.",
"properties": {
"url": {
"description": "Public http(s) URL of the x402 endpoint to lint (required).",
"format": "uri",
"type": "string"
}
},
"required": [
"url"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"checks": {
"items": {
"properties": {
"detail": {
"description": "Human explanation of the finding.",
"type": "string"
},
"level": {
"enum": [
"pass",
"warn",
"fail",
"info"
],
"type": "string"
},
"rule": {
"description": "Rule id, e.g. description_length, resource_identity, accepts[0].network.",
"type": "string"
}
},
"required": [
"rule",
"level",
"detail"
],
"type": "object"
},
"type": "array"
},
"isX402": {
"description": "False when the target is not a decodable x402 402 (then a single info check).",
"type": "boolean"
},
"summary": {
"properties": {
"fails": {
"type": "integer"
},
"warns": {
"type": "integer"
}
},
"required": [
"fails",
"warns"
],
"type": "object"
},
"url": {
"description": "The URL that was linted.",
"type": "string"
}
},
"required": [
"url",
"isX402",
"checks",
"summary"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}