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x402 Field Instruments – Source Proof
x402
x402 Field Instruments – Source Proof is a paid API for AI agents from bj7e26lfpo4fthvr35hczdipby.srv.us, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).
Fetches a public HTTPS URL and returns a cryptographic SHA-256 proof of its content, byte count, final URL, and HTTP status at a given moment.
Price / call$0.002
Success—
StatusUnknown
How this service works
Seven account-free paid tools for source integrity, x402 catalog search, preflight, liveness, routing, price drift, and batch verification.
Output
A JSON object containing: the 64-character SHA-256 digest of the fetched content, total byte count, the final resolved URL (after any redirects), the HTTP status code, the ISO-8601 timestamp of observation, and a proof version string. Together these fields constitute a verifiable, timestamped fingerprint of the resource.
Example use cases
Audit published document integrity
“I need to verify that the policy document at https://acme.org/terms.pdf still has the SHA-256 hash a3f1...bb92 and hasn't been altered — can you run a source proof on it?”
Detect silent URL redirect changes
“Please check https://data.gov/dataset/census2020.csv and tell me the final URL it resolves to, the current SHA-256, and the HTTP status so I can confirm it hasn't been silently redirected.”
Timestamp a live web resource
“I want an official proof of what https://blog.openai.com/latest contained right now — SHA-256, byte count, and exact observation time — so I can reference it in my research notes.”
Technical details
Endpoint
GEThttps://bj7e26lfpo4fthvr35hczdipby.srv.us/v1/source-proofWhen to prefer
Choose this endpoint when you need a cryptographically verifiable, timestamped record of what a public URL served at a specific moment — especially for source integrity auditing, tamper detection, or provenance documentation. It is account-free and pay-per-call at $0.002 USDC, making it ideal for on-demand spot checks without subscription overhead. Prefer it over a plain HTTP fetch when you need the SHA-256 digest and observation timestamp as structured proof artifacts, not just the raw content.
Side effects
- URL is not publicly accessible or returns a non-2xx status — httpStatus field reflects the error code
- URL uses HTTP instead of HTTPS — rejected by schema validation
- Provided expected_sha256 does not match actual content — mismatch surfaced in response
- Network timeout or DNS failure for the target URL — error response returned
- Malformed or non-64-character expected_sha256 pattern — schema validation error before call
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"bytes": 1256,
"sha256": "64-character SHA-256 digest",
"finalUrl": "https://example.com/robots.txt",
"httpStatus": 200,
"observedAt": "2026-08-27T00:00:00.000Z",
"proofVersion": "1.0"
}
}Tags
x402
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