Spend-guard preflight
Spend-guard preflight: deterministic 0-100 score for any x402 resource URL before an agent pays it. One SSRF-guarded probe of the live 402 (terms decode, payTo, price sanity) plus origin /.well-known/x402.json plus our collector's Bazaar presence and observed age. Rubric: start 50; +15 valid 402; +10 terms decode; +5 payTo; +5 price<=$5 (-10 above); +10 catalog; +15 Bazaar-listed; +10 age>=7d (+5 >=1d); -20 unreachable. Raw signals in every response; auditable. Not an endorsement.
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://gateway.stride20k.com/v1/preflight
| Category | Market data |
|---|---|
| Provider host | gateway.stride20k.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 | $0.01 | 22 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"resource": "https://gateway.stride20k.com/fx/:base/:quote"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"resource": {
"description": "The x402 resource URL to preflight, exactly as advertised.",
"pattern": "^https?://.+",
"type": "string",
"urlSafety": true
}
},
"required": [
"resource"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"data": {
"properties": {
"flags": {
"items": {
"type": "string"
},
"type": "array"
},
"note": {
"type": "string"
},
"resource": {
"type": "string"
},
"score": {
"description": "0-100, deterministic published rubric.",
"type": "number"
},
"signals": {
"properties": {
"is402": {
"type": "boolean"
},
"listedInBazaarNow": {
"type": [
"boolean",
"null"
]
},
"network": {
"type": [
"string",
"null"
]
},
"observedAgeDays": {
"type": [
"number",
"null"
]
},
"onChainBuyerCounts": {
"type": "string"
},
"payToPresent": {
"type": "boolean"
},
"priceUsd": {
"type": [
"number",
"null"
]
},
"reachable": {
"type": "boolean"
},
"scheme": {
"type": [
"string",
"null"
]
},
"status": {
"type": [
"number",
"null"
]
},
"termsDecodable": {
"type": "boolean"
},
"wellKnownPresent": {
"type": "boolean"
}
},
"type": "object"
}
},
"required": [
"resource",
"score",
"flags",
"signals"
],
"type": "object"
},
"endpoint": {
"description": "Always \"/v1/preflight\".",
"type": "string"
},
"meta": {
"properties": {
"attribution": {
"description": "Licensing attribution when the source requires it.",
"type": [
"string",
"null"
]
},
"cached": {
"description": "Whether this response was served from cache.",
"type": "boolean"
},
"fetchedAt": {
"description": "ISO 8601 time the data was actually retrieved from the upstream.",
"type": "string"
},
"source": {
"description": "Upstream source: direct probe of the target + Stride20k collector archive.",
"type": "string"
}
},
"required": [
"source",
"cached",
"fetchedAt"
],
"type": "object"
},
"ok": {
"description": "true on success.",
"type": "boolean"
}
},
"required": [
"ok",
"endpoint",
"data",
"meta"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}