Verify whether a supplied public source page currently supports one atomic factual claim
Verify whether a supplied public source page currently supports one atomic factual claim. Returns supported, contradicted, or insufficient-evidence plus source snippets, or explicit blocked/unreachable/unsupported states. Not a general fact checker or web search.
10000 (raw units)
price
6
calls / 30d
4
unique payers
2026-09-14
updated
Provider
source-claim-proof.mattskowronis.workers.dev · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0x22B3D4485C8Dcd8FC4840a7570664747c9055530",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "10000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"body": {
"claim": "The event begins at 7:00 PM.",
"url": "https://example.com/event"
},
"bodyType": "json",
"method": "POST",
"type": "http"
},
"output": {
"example": {
"claim": "The event begins at 7:00 PM.",
"content_hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
"evidence": [
{
"evidence_type": "visible_text",
"location": "Schedule",
"polarity": "supports",
"text": "Doors 6:30 PM. Program begins at 7:00 PM."
}
],
"final_url": "https://example.com/event",
"reasoning_summary": "Visible schedule text states the program begins at 7:00 PM.",
"retrieval_method": "direct_http",
"retrieved_at": "2026-08-18T22:00:00.000Z",
"service_version": "1.0.0",
"source_status": "verified",
"source_url": "https://example.com/event",
"verdict": "supported"
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"claim": {
"description": "One atomic factual assertion to check against that source only.",
"maxLength": 500,
"minLength": 3,
"type": "string"
},
"url": {
"description": "Public HTTP or HTTPS source page URL to inspect.",
"maxLength": 2048,
"type": "string"
}
},
"required": [
"url",
"claim"
]
},
"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": false,
"properties": {
"claim": {
"description": "The claim that was checked.",
"type": "string"
},
"content_hash": {
"description": "Hash of retrieved source content.",
"type": "string"
},
"evidence": {
"description": "Compact source snippets used for the verdict.",
"items": {
"additionalProperties": false,
"properties": {
"evidence_type": {
"description": "Where the snippet came from on the source page.",
"enum": [
"visible_text",
"heading",
"json_ld",
"meta",
"status"
],
"type": "string"
},
"location": {
"description": "Page location of the snippet, or null if unknown.",
"type": [
"string",
"null"
]
},
"polarity": {
"description": "Whether the snippet supports, contradicts, or is neutral.",
"enum": [
"supports",
"contradicts",
"neutral"
],
"type": "string"
},
"text": {
"description": "Source snippet that supports or contradicts the claim.",
"maxLength": 240,
"type": "string"
}
},
"required": [
"text",
"location",
"evidence_type",
"polarity"
],
"type": "object"
},
"maxItems": 3,
"type": "array"
},
"final_url": {
"description": "Final URL after redirects.",
"type": "string"
},
"reasoning_summary": {
"description": "Short machine-readable reason for the verdict.",
"maxLength": 400,
"type": "string"
},
"retrieval_method": {
"description": "How the source page was fetched.",
"enum": [
"direct_http",
"browser_run",
"official_api",
"unsupported"
],
"type": "string"
},
"retrieved_at": {
"description": "UTC timestamp of the check.",
"type": "string"
},
"service_version": {
"description": "Source Claim Proof service version.",
"type": "string"
},
"source_status": {
"description": "verified, blocked, unreachable, unsupported, or insufficient_evidence.",
"enum": [
"verified",
"blocked",
"unreachable",
"unsupported",
"insufficient_evidence"
],
"type": "string"
},
"source_url": {
"description": "Requested source URL.",
"type": "string"
},
"verdict": {
"description": "supported, contradicted, or insufficient_evidence.",
"enum": [
"supported",
"contradicted",
"insufficient_evidence"
],
"type": "string"
}
},
"required": [
"verdict",
"claim",
"source_url",
"final_url",
"source_status",
"evidence",
"reasoning_summary",
"retrieval_method",
"retrieved_at",
"content_hash",
"service_version"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://source-claim-proof.mattskowronis.workers.dev/v1/verify" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://source-claim-proof.mattskowronis.workers.dev/v1/verify");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://source-claim-proof.mattskowronis.workers.dev/v1/verify")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/6445.json, and this resource appears in /discovery/resources and /discovery/search.