Free x402 endpoint linter: checks the unpaid 402 challenge, payTo/asset/amount, CORS, discovery.
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Lint a PaymentRequired object you already have (decoded JSON, a JSON string, or the raw base64 PAYMENT-REQUIRED header). Same field/value checks as lint_x402_endpoint, no network access. Free.
Object, JSON string, or base64 header value
Optional: the URL it was served from, to check resource.url
This tool isn't marked read-only, so it may change something on the server or in an account you connected.
Lint a PaymentRequired object you already have (decoded JSON, a JSON string, or the raw base64 PAYMENT-REQUIRED header). Same field/value checks as lint_x402_endpoint, no network access. Free.
| Argument | Type | Description |
|---|---|---|
| url | string | Optional: the URL it was served from, to check resource.url |
| payment_required* | any | Object, JSON string, or base64 header value |
{
"type": "object",
"required": [
"payment_required"
],
"properties": {
"url": {
"type": "string",
"description": "Optional: the URL it was served from, to check resource.url"
},
"payment_required": {
"description": "Object, JSON string, or base64 header value"
}
}
}Unpaid lint of an x402 endpoint: fetches the 402 (GET and POST), then checks the challenge (version, accepts[] fields, CAIP-2 network, payTo/asset/amount sanity, EIP-712 name/version, timeouts, resource), transport (redirects, cache headers, CORS) and discovery files. Returns findings with ids, severities and fixes. Never pays. Free.
| Argument | Type | Description |
|---|---|---|
| url* | string | The paid x402 URL |
| method | string | Default auto: tries both |
{
"type": "object",
"required": [
"url"
],
"properties": {
"url": {
"type": "string",
"description": "The paid x402 URL"
},
"method": {
"enum": [
"auto",
"GET",
"POST"
],
"type": "string",
"description": "Default auto: tries both"
}
}
}