Sign Reader — read one x402 endpoint's 402 challenge
Sign Reader — read one x402 endpoint's 402 challenge: both wire formats (v2 PAYMENT-REQUIRED header, v1 JSON body) parsed and normalized (network, asset, amount atomic and exact decimal, payTo, scheme), malformed fields named, declared-vs-live mismatches (method included) when you pass your catalogue entry, and a compatibility verdict for the official Python and TypeScript x402 SDKs. Probe is unpaid. Use this when a checker's parser keeps choking on sellers' signs.
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://stall-row-production.up.railway.app/v1/sign-read
| Category | Code and developer |
|---|---|
| Provider host | stall-row-production.up.railway.app |
| Networks | eip155:8453 |
| 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 |
|---|---|---|---|---|
| 2026-10-31 | valid payment request | 402 | $0.01 | 901 ms |
Example input (from the provider)
{
"body": {
"url": "https://example.com/v1/verdict"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"declared_amount": {
"type": [
"string",
"null"
]
},
"declared_method": {
"type": [
"string",
"null"
]
},
"declared_network": {
"type": [
"string",
"null"
]
},
"declared_pay_to": {
"type": [
"string",
"null"
]
},
"url": {
"type": "string"
}
},
"required": [
"url"
],
"type": "object"
},
"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": {
"accepts": {
"items": {
"type": "object"
},
"type": "array"
},
"challenge_found": {
"type": "boolean"
},
"defects": {
"items": {
"type": "object"
},
"type": "array"
},
"http_status": {
"type": [
"integer",
"null"
]
},
"limits": {
"type": "string"
},
"mismatches": {
"items": {
"type": "object"
},
"type": "array"
},
"origin": {
"type": "string"
},
"read_at": {
"type": "string"
},
"sdk_compat": {
"type": [
"object",
"null"
]
},
"url": {
"type": "string"
},
"x402_version": {
"type": [
"integer",
"null"
]
}
},
"required": [
"url",
"challenge_found",
"accepts"
],
"type": "object"
},
"schema": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}