{"uid":"cap_z9Hg0a6n4NK_Q_1QNT4LQ","slug":"delx-idempotency-fingerprint-02317031","name":"Delx Idempotency Fingerprint","description":"Create a stable SHA-256 idempotency fingerprint from a scope and canonical payload without storing state — call when writing a ledger or workflow event that must not double-apply. Use before side effects when composing multi-step agent jobs—the same loyalty/workflow demand band agents already pay for on Bazaar, but fully local. Returns deterministic machine-readable JSON for $0.003 USDC via x402 on Base. Execution is first-party, local-only, stateless, and memory-only with no paid upstream, no…","url":"https://api.delx.ai/api/v1/x402/idempotency-fingerprint","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"scope":{"type":"string","description":"Caller-owned namespace string mixed into the fingerprint."},"payload":{"type":"object","description":"JSON payload to fingerprint; values are hashed, not retained."}}},"responseSchema":{"type":"json","example":{"scope":"loyalty","schema":"delx/util-idempotency-fingerprint/v1","algorithm":"sha256","fingerprint":"dc22b29600e074df71fc0f9b0260185e822b228cca615d37992a31dc14eb8f45","values_returned":false}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_nFL9chwh4clQ_U6hDHM32","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Generates a deterministic SHA-256 idempotency fingerprint from a caller-supplied scope and JSON payload without storing any state.","exampleAgentPrompt":"Before I write this loyalty-event to the ledger, generate an idempotency fingerprint using scope 'loyalty:user-42' and this canonical payload: {\"userId\":\"42\",\"points\":150,\"eventType\":\"purchase\"} — I need a stable SHA-256 hash to make sure the event doesn't double-apply.","exampleUseCases":[{"title":"Prevent double-posting a ledger entry","prompt":"I'm about to commit a payment event to the ledger — generate an idempotency fingerprint with scope 'payments:txn-9981' and payload {\"amount\":49.99,\"currency\":\"USDC\",\"recipientId\":\"acct-77\"} so I can verify it hasn't already been applied."},{"title":"Deduplicate a multi-step agent workflow","prompt":"Before my agent fires the next step in the onboarding workflow, create a SHA-256 fingerprint with scope 'onboarding:session-abc123' and payload {\"userId\":\"u-555\",\"step\":\"email-verify\",\"ts\":\"2024-06-01T10:00:00Z\"} to guard against replay."},{"title":"Guard a loyalty-reward event from replay","prompt":"Hash this reward event so I can check for duplicates before crediting the account — use scope 'rewards:campaign-spring24' and payload {\"memberId\":\"m-002\",\"rewardType\":\"bonus_points\",\"value\":500}."}],"resultDescription":"Returns a deterministic machine-readable JSON object containing the computed SHA-256 fingerprint string derived from the provided scope and canonical payload. No state is stored; the same inputs always produce the same fingerprint, making it safe to call multiple times for verification.","failureModes":["Missing or empty scope field returns a validation error","Payload is not a valid JSON object — returns a schema error","Malformed request body returns a 400 bad request","Payment failure or insufficient USDC balance returns a 402 error","Network timeout on the x402 payment handshake"],"whenToPreferThis":"Choose this endpoint when you need a stateless, deterministic idempotency key derived from a canonical payload — especially before committing ledger entries, workflow events, or side-effecting operations in multi-step agent pipelines. It is ideal when you want no server-side state storage, no upstream dependency, and a guaranteed reproducible SHA-256 hash from the same inputs. Prefer it over rolling your own hashing logic when you need a paid, auditable, first-party fingerprinting step in an x402-based agent workflow.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T19:01:37.039Z","isFirstParty":false}