Determine whether a previously accepted x402 service payment contract is still e
Determine whether a previously accepted x402 service payment contract is still equivalent enough to proceed. Compares one live unpaid 402 challenge, using a caller-supplied GET or POST request shape, against a caller-held baseline bound to that request identity. Not uptime monitoring, a trust score, a webhook, a marketplace crawl, or a generic POST {} probe of every x402 resource.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
230 msmedian answer time
$0.01listed price per call
$0.01price 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
POST https://api.agentmercantile.com/v1/x402-service-change-snapshot
| Category | Search and research |
|---|---|
| Provider host | api.agentmercantile.com |
| 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 |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.01 | 230 ms |
Example input (from the provider)
{
"body": {
"method": "POST",
"resource_url": "https://api.agentmercantile.com/v1/url-context"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"baseline": {
"description": "Optional caller-held reusable payment-contract baseline bound to this request identity.",
"type": "object"
},
"body": {
"description": "Optional JSON object for POST probes only.",
"type": "object"
},
"method": {
"description": "Required unpaid 402 probe method. Not inferred from discovery.",
"enum": [
"GET",
"POST"
],
"type": "string"
},
"resource_url": {
"description": "One public HTTPS x402 resource URL on port 443.",
"format": "uri",
"type": "string"
}
},
"required": [
"resource_url",
"method"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"additionalProperties": true,
"properties": {
"decision": {
"enum": [
"BASELINE_CREATED",
"CONTINUE",
"REVIEW",
"STOP",
"UNKNOWN"
],
"type": "string"
},
"limitations": {
"items": {
"type": "string"
},
"type": "array"
},
"machine": {
"enum": [
"VM08"
],
"type": "string"
},
"methodology_version": {
"enum": [
"x402-service-change-snapshot-0.1.0"
],
"type": "string"
},
"status": {
"enum": [
"OK",
"PARTIAL",
"HOLD"
],
"type": "string"
}
},
"required": [
"status",
"machine",
"methodology_version",
"decision",
"limitations"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}