{"uid":"cap_11kqClyyQKs--elGfUIHD","slug":"task-checkpoint-evidence-af6e7d2d","name":"Task Checkpoint Evidence","description":"Bind task state, sequence and checkpoint hash in signed evidence","url":"https://phion.systems/v1/paid/trust/task-checkpoint-evidence?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input","output"],"properties":{"input":{"type":"object","required":["body"],"properties":{"body":{"type":"object","additionalProperties":true}}},"output":{"type":"object","required":["example"],"properties":{"example":{"type":"object","additionalProperties":true}}}}},"responseSchema":{"type":"json"},"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_uCUSmZTkj22dVd3wPgFsq","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":"Binds task state, sequence number, and checkpoint hash into a signed cryptographic evidence record for AI agent task integrity","exampleAgentPrompt":"Create a signed checkpoint evidence record binding the current task state 'payment_confirmed', sequence number 3, and checkpoint hash 'sha256:abc123...' so I have a tamper-evident audit record for this agent task.","exampleUseCases":[{"title":"Audit trail for multi-step agent pipeline","prompt":"My agent just completed the data-validation phase of a 5-step pipeline — can you create signed checkpoint evidence binding task state 'validation_complete', sequence 2, and the checkpoint hash so I have a cryptographic record before moving to the next step?"},{"title":"Commerce journey integrity checkpoint","prompt":"Before my agent submits the final payment, I need a signed evidence record locking in task state 'pre_payment', sequence number 4, and the hash of the current task context so we have a tamper-proof checkpoint."},{"title":"Dispute-resolution evidence for agent task","prompt":"I need verifiable proof that my agent task reached 'delivery_confirmed' state at sequence step 6 — can you bind the task state and checkpoint hash into a signed evidence record I can use if there's a dispute?"}],"resultDescription":"A signed evidence record cryptographically binding the task state, sequence number, and checkpoint hash. The receipt serves as a tamper-evident attestation that can be used for audit trails, dispute resolution, or integrity verification of an AI agent's task progression.","failureModes":["Invalid or missing task state returns 400 error","Malformed checkpoint hash causes binding failure","Sequence number out of expected order may be rejected","Payment failure via x402 prevents evidence generation","Signature generation failure if signing infrastructure is unavailable"],"whenToPreferThis":"Choose this endpoint when you need a cryptographically signed, tamper-evident record binding a specific task state and sequence to a checkpoint hash — particularly for multi-step agentic workflows where you need audit trails, dispute-resolution evidence, or integrity guarantees at discrete task phases. Prefer this over generic logging when non-repudiability and signed provenance are required.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-20T06:50:57.241Z","isFirstParty":false,"canonicalSlug":"task-checkpoint-evidence-af6e7d2d"}