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Clearsigned Claim Verification
x402
Clearsigned Claim Verification is a paid API for AI agents from verify.clearsigned.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).
Submits a claim with evidence to receive a cryptographically signed, ledger-chained verification receipt with an Ed25519 signature
Price / call$0.01
Success—
StatusUnknown
How this service works
Clearsigned — the trust layer with no stake in the outcome. Submit {claim, evidence[]}, receive an Ed25519-SIGNED, evidence-bearing receipt (verify offline against GET /pubkey; every receipt is chained in the public ledger at GET /ledger/verify). Flat price, verdict-independent; refunds only for failure to deliver. Current mode is honestly labeled in each receipt.
Output
An Ed25519-signed receipt containing the submitted claim, evidence references, a verdict label, a current-mode indicator, and a chain entry that can be independently verified offline using the public key from GET /pubkey or cross-checked on the public ledger via GET /ledger/verify. Receipt is verdict-independent (flat $0.01 USDC price regardless of outcome); refunds issued only if delivery fails.
Example use cases
Dispute-proof payment attestation
“I need to prove that our contractor delivered the work by the deadline — submit the claim 'Deliverable D-3 received by 2024-12-01' along with the timestamped email and the signed acceptance form to Clearsigned and get me a ledger-chained signed receipt I can show in arbitration.”
Content authenticity verification
“I want a cryptographically signed receipt confirming that this article draft existed and was unmodified as of today — submit the claim 'Article v1.0 authored by J. Smith, 2025-01-20' with the SHA-256 hash of the file as evidence and get me a Clearsigned receipt I can verify offline.”
Regulatory compliance attestation
“We need to attest that our KYC check on customer account C-9923 was completed on 2025-03-10 — submit that claim along with the scanned ID document and the compliance checklist to Clearsigned and get back the signed, ledger-anchored receipt for our audit trail.”
Technical details
Endpoint
POSThttps://verify.clearsigned.com/verify/t1When to prefer
Choose this endpoint when you need an impartial, cryptographically signed, offline-verifiable attestation of a claim backed by evidence — particularly when the verifier cannot or should not call back to a live API. Its flat, verdict-independent pricing and public ledger chaining make it suitable for dispute resolution, audit trails, compliance documentation, and content provenance use cases where neither party should be able to claim the verifier had a stake in the outcome.
Side effects
- Missing or malformed claim field returns validation error
- Evidence array empty or malformed prevents receipt issuance
- Service downtime triggers refund eligibility per stated policy
- Signature verification failure when checked offline may indicate receipt tampering or wrong public key version
- Current mode label may reflect non-production/test mode, limiting legal weight of receipt
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| claim | string | The claim to verify (max 10k chars) |
| evidence | array | Supporting material; admitted as secondary-tier evidence |
Tags
x402
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