Verify an x402 seller before paying it
Verify an x402 seller before paying it: does it exist and respond with a well-formed 402 challenge, is its own declared input/output schema internally consistent, and is its payout address sanctioned? Checked live against the seller itself plus Chainalysis's sanctions oracle and Blockscout (Base payTo addresses only). Confirms the checkable things about a seller check out -- not a guarantee of trustworthiness, which no free source can promise.
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
POST https://goodsong.dev/verify/seller
| Category | Company and compliance |
|---|---|
| Provider host | goodsong.dev |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
We never call tools that send, buy, move money or file anything, not even without paying.
Example input (from the provider)
{
"body": {
"method": "POST",
"resource_url": "https://api.example.com/paid-endpoint"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"description": "Provide the exact x402 resource URL; method defaults to POST.",
"properties": {
"method": {
"description": "HTTP method that triggers the seller's 402 challenge.",
"enum": [
"GET",
"POST"
],
"type": "string"
},
"resource_url": {
"description": "The x402 resource URL to verify.",
"type": "string"
}
},
"required": [
"resource_url"
]
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"canonical": {
"type": [
"object",
"null"
]
},
"checks": {
"type": "object"
},
"cost": {
"type": "object"
},
"evidence": {
"type": "array"
},
"latency_ms": {
"type": "integer"
},
"verdict": {
"enum": [
"confirmed",
"contradicted",
"unknown"
],
"type": "string"
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}