{"spec":"Golden-Vector Provenance","version":"0.2","summary":"A convention for verified-computation services on the paid agent web: every answer is reproducible, cited, and independently checkable without trusting the server. v0.2 adds the audit-grade Verification Receipt (GVP-7).","requirements":[{"id":"GVP-1","level":"MUST","title":"Provenance on every answer","text":"Return a formula/method trace, versioned public source citations with a data vintage, and a reproducible content hash of the response."},{"id":"GVP-2","level":"MUST","title":"Free golden vector per tool","text":"Publish a canonical input set + expected result + expected hash at a free endpoint so any client can recompute and confirm without paying or trusting."},{"id":"GVP-3","level":"MUST","title":"Free hash re-check","text":"Provide a free endpoint that recomputes a prior response hash from its inputs so tampering is detectable."},{"id":"GVP-4","level":"SHOULD","title":"Free claim verifier","text":"Provide a free endpoint that confirms whether a claimed answer matches the service computation for given inputs, WITHOUT revealing the answer (boolean + confidence only)."},{"id":"GVP-5","level":"MUST","title":"Determinism","text":"Identical inputs always produce an identical result and hash; no hidden state or time-dependence beyond a declared data vintage."},{"id":"GVP-6","level":"MUST","title":"Machine discoverability","text":"Advertise these endpoints in OpenAPI, llms.txt, an agent-card, and/or the x402 bazaar extension."},{"id":"GVP-7","level":"MAY","title":"Audit-grade Verification Receipt","text":"Offer a receipt that packages a GVP-1 answer into a portable, filable record: canonical inputs, result, method, versioned sources + dataVintage, the reproducible responseHash, a free golden re-derivation pointer, an OPTIONAL Ed25519 issuer attestation (attests issuance, not correctness), an OPTIONAL on-chain identity anchor (e.g. ERC-8004), a timestamp, and a human \"how to independently verify\" block. Correctness stays proven by recompute-trust; the receipt is the record a professional files for audit/insurance."}],"hash":{"algorithm":"sha256","canonicalization":"UTF-8 JSON with recursively sorted object keys over {endpoint, inputs, result, method, dataVintage}"},"receipt":{"title":"GVP-7 Verification Receipt (v0.2)","schema":"https://x402toll.com/gvp-receipt.schema.json","trustModel":"recompute-trust primary; signature attests issuance (who + when), never correctness","fields":["receiptVersion","issuer","issuedAt","tool","endpoint","canonicalInputs","result","method","dataVintage","sources","responseHash","goldenVector","recheckUrl","onChainAnchor","howToVerify","signature","disclaimer"],"signature":{"alg":"Ed25519","publicKey":"https://x402toll.com/.well-known/receipt-pubkey.json","signs":"canonicalJson({responseHash, endpoint, dataVintage, issuer, agentId, issuedAt})"}},"conformance":{"GVP-Core":"meets GVP-1, 2, 3, 5, 6","GVP-Verify":"GVP-Core plus GVP-4","GVP-Receipt":"GVP-Verify plus GVP-7 (audit-grade receipts)"},"referenceImplementation":"https://x402toll.com","endpoints":{"golden":"https://x402toll.com/v1/golden/:id","verifyHash":"https://x402toll.com/v1/verify-hash","verify":"https://x402toll.com/v1/verify","verifyBatch":"https://x402toll.com/v1/verify/batch","gvpCheck":"https://x402toll.com/v1/gvp/check","badge":"https://x402toll.com/v1/gvp/badge.svg","registry":"https://x402toll.com/v1/gvp/registry","receipt":"https://x402toll.com/v1/receipt/:id","receiptPubkey":"https://x402toll.com/.well-known/receipt-pubkey.json","spec":"https://x402toll.com/v1/spec"},"neutralVerifier":{"verify":"POST /v1/verify — free: confirm/deny a claimed answer from ANY source in our domains, leak-safe (pass/fail + field names only).","batch":"POST /v1/verify/batch — paid: batch-verify up to 100 claims into a signed, filable compliance report (engagement, not per-call).","gvpCheck":"POST /v1/gvp/check — free: check ANY GVP service response for self-consistency + GVP-1 conformance and get a self-serve embeddable badge.","registry":"GET /v1/gvp/registry (+ /registry.json) — free: the public list of GVP-conformant services; GET /v1/gvp/badge.svg — the embeddable badge."},"status":"draft · v0.2 · authored by Tollbooth · open for adoption","license":"CC0 / public domain — adopt freely"}