{"uid":"cap_Do6JS2XxpIcnxaS3wt6E7","slug":"fairseal-blockchain-notarization-ef1d8105","name":"FairSeal Blockchain Notarization","description":"Anchor an AI agent decision or audit record to Base mainnet. Submit {schema, payload_hash (SHA-256 hex, 64 chars), metadata}; service queues into a Merkle batch and returns a receipt with pending_anchor status immediately. Full Merkle proof and on-chain anchor_tx available via free GET /v1/notarize/:receipt_id after batch anchors (within batch_threshold receipts or 120s). Include Idempotency-Key header to prevent double-charges on retry.","url":"https://x402.fairseal.io/v1/notarize?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["schema","payload_hash","metadata"],"properties":{"schema":{"enum":["agent_decision","audit_evidence","probe_record"],"type":"string"},"metadata":{"type":"object","description":"Schema-specific metadata. agent_decision requires {agent_id, decided_at, input_hash, decision_hash}"},"payload_hash":{"type":"string","pattern":"^[0-9a-f]{64}$","description":"SHA-256 hex of full payload (64 lowercase hex chars)"}}},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.05","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.05/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_183QqbQd-LxP-vi9gK4nm","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.05","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Anchors an AI agent decision or audit record to Base mainnet via a Merkle batch, returning a receipt immediately and a full on-chain proof once the batch settles.","exampleAgentPrompt":"Anchor my agent's decision record to Base mainnet — the schema is agent_decision, the payload hash is a3f1...c2d9 (64-char SHA-256), and the metadata includes agent_id 'agent-42', decided_at '2024-06-01T12:00:00Z', input_hash 'e5b2...f7a1', and decision_hash 'd8c3...9b0e'. Use an idempotency key so we don't get double-charged if the request retries.","exampleUseCases":[{"title":"Audit trail for autonomous trading agent","prompt":"My trading agent just made a portfolio rebalancing decision — anchor it to Base mainnet as an agent_decision with agent_id 'trader-bot-7', decided_at '2024-06-10T09:30:00Z', the payload hash 'b4d2e1f3a5c7d9e0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4', and the decision_hash and input_hash from this run — I need an immutable on-chain record for compliance."},{"title":"Notarize audit evidence for regulatory review","prompt":"I have a piece of audit evidence I need notarized on Base mainnet — schema is audit_evidence, payload hash is 'c3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4', and the metadata includes the source system ID and timestamp. Can you submit it and give me a receipt?"},{"title":"Record AI probe result for model monitoring","prompt":"Store a probe_record on the blockchain for my model monitoring pipeline — the payload SHA-256 is 'f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2' and the metadata includes probe_id 'probe-99' and run_at '2024-06-15T08:00:00Z'. I'll poll for the Merkle proof once the batch anchors."}],"resultDescription":"An immediate receipt object with a receipt_id and pending_anchor status. Once the Merkle batch settles (within the batch threshold or 120 seconds), a GET /v1/notarize/:receipt_id returns the full Merkle proof and the on-chain anchor transaction hash on Base mainnet.","failureModes":["Invalid payload_hash format (not 64 lowercase hex chars) — 400 validation error","Missing required metadata fields for the chosen schema (e.g. agent_id for agent_decision) — 400 error","Payment failure or insufficient USDC balance — 402 Payment Required","Duplicate submission without Idempotency-Key may result in double charges — use header to prevent","Batch anchor delay beyond 120s in case of network congestion — proof may be temporarily unavailable","Unknown schema type provided — 400 enum validation error"],"whenToPreferThis":"Choose this endpoint when you need a tamper-proof, on-chain record of an AI agent decision, audit event, or probe result anchored to Base mainnet with a verifiable Merkle proof. It is ideal for compliance, governance, and accountability use cases where you need an immutable cryptographic attestation retrievable later. Use the Idempotency-Key header on retries to avoid double-charges.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-23T00:33:21.648Z","isFirstParty":false,"canonicalSlug":"fairseal-blockchain-notarization-ef1d8105"}