{"uid":"cap_zrPF4IVczET93F99AZmFI","slug":"agent-exec-handoff-briefing-pay-per-use-agent-state-transfer-4ca49fb5","name":"Agent-Exec Handoff Briefing — Pay-Per-Use Agent State Transfer","description":"Accountless, pay-per-use code execution for software agents: submit source code, get stdout, stderr and exit code back from an isolated, network-less sandbox. No account, no API key -- possession of valid payment is sufficient.","url":"https://agent-exec.448c.org/handoff?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","required":["done","notDone","inFlight","pickUpFirst"],"properties":{"done":{"type":"array","description":"What is DONE. EVERY entry must have confidence 'measured' with non-null evidence -- a briefing cannot claim something is finished on unverified intent. Violating this is a free 400 (HANDOFF_DONE_REQUIRES_MEASURED), not a silent acceptance."},"notDone":{"type":"array","description":"What is NOT done. May be measured or unverified."},"inFlight":{"type":"array","description":"What was IN FLIGHT at the cut -- neither finished nor abandoned. May be measured or unverified."},"pickUpFirst":{"type":"string","description":"What the successor should do FIRST. Mandatory and non-empty: a briefing with no next action is not a handoff."}}},"responseSchema":{"type":"object","required":["id","expiresAt","payment"],"properties":{"id":{"type":"string","format":"uuid","description":"The handoff_id -- give this to the successor; it needs nothing else."},"payment":{"type":"object","properties":{"asset":{"type":"string"},"payer":{"type":"string","description":"The paying wallet's address."},"amount":{"type":"string","description":"Atomic units of the settlement asset that were charged."},"network":{"type":"string"},"transaction":{"type":"string","description":"On-chain settlement transaction hash."}}},"expiresAt":{"type":"integer","description":"Unix ms this briefing is swept. GET /handoff/{id} answers 410 between the deadline and the sweep, then 404."}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.0053","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":"$0.0053/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.0053","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.0053","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_GcQc2goh8J_7OSjQlwQVV","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.0053","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Creates a structured handoff briefing that captures an AI agent's current state (done, not-done, in-flight work, and next action) so a successor agent can seamlessly pick up where it left off, paid per-use via USDC with no account required.","exampleAgentPrompt":"Create a handoff briefing for my successor agent: mark 'fetch and parse the dataset' as done (confirmed by the 200-byte CSV written to disk), list 'run the regression analysis' as not done, nothing is in-flight, and tell the next agent to start by loading the CSV and fitting the model.","exampleUseCases":[{"title":"Multi-agent pipeline checkpoint","prompt":"I need to hand off to the next agent in my pipeline — mark 'scraped all 50 product pages' as done (evidence: 50 JSON files saved), 'write the summary report' as not done, nothing in flight, and tell my successor to start by reading those JSON files and generating the report."},{"title":"Agent crash recovery briefing","prompt":"My agent just crashed mid-task. Save a handoff: completed tasks are 'authenticated with the API' (measured, got a 200 token response) and 'fetched user list' (measured, 312 records in users.json); not done is 'send notification emails'; nothing is in-flight; and tell the successor to start by sending emails to each user in users.json."},{"title":"Long-running task delegation","prompt":"Split this job across two agents — the first agent finished 'downloading the model weights' (confirmed by SHA256 checksum match), nothing else done, still in-flight is 'pre-processing the training data', and the successor should pick up by finishing that pre-processing before starting training."}],"resultDescription":"Returns a UUID handoff_id the successor agent can use to retrieve the briefing via GET /handoff/{id}, along with an expiry timestamp (Unix ms) after which the briefing is swept and returns 410 then 404, plus a payment receipt showing the asset, payer wallet address, amount in atomic USDC units, network, and on-chain transaction hash.","failureModes":["400 HANDOFF_DONE_REQUIRES_MEASURED — a 'done' entry lacks confidence 'measured' or has null evidence; fix by providing verified evidence for all completed tasks","400 validation error — missing required fields (done, notDone, inFlight, or pickUpFirst)","400 empty pickUpFirst — the next-action string must be non-empty","402 Payment Required — payment not attached or payment is invalid/insufficient","Payment settlement failure — on-chain transaction fails, call is rejected","Briefing expiry — successor retrieves after expiresAt, gets 410 Gone until sweep then 404 Not Found"],"whenToPreferThis":"Use this endpoint when you need to transfer agent state between runs or agent instances without managing accounts or API keys — ideal for agentic pipelines, crash recovery, or multi-agent orchestration where the payer just needs a valid USDC payment. Prefer this over custom state-passing solutions when you want a standardized, time-bounded briefing with strict validation that 'done' items are actually verified.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-10T06:32:43.748Z","isFirstParty":false,"canonicalSlug":"agent-exec-handoff-briefing-pay-per-use-agent-state-transfer-4ca49fb5"}