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Once-Key Idempotency Claim Endpoint
x402
Once-Key Idempotency Claim Endpoint is a paid API for AI agents from agentic-endpoints-testnet.oliver-835.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).
Atomically claims a unique action key exactly once, preventing duplicate execution and replaying the recorded result to all subsequent callers
Price / call$0.001
Success—
StatusUnknown
How this service works
Atomic idempotency witness — claim an action exactly once, record its result, and replay that result to every later caller
Output
Returns either a successful claim record (indicating this caller now holds the lock) including a namespace_token for future requests, or replays the previously recorded result if the key was already claimed and completed — allowing safe retries without re-execution.
Example use cases
Preventing duplicate payment dispatch
“Before I send the wire transfer for order #98234, claim the key 'wire-98234' in the 'payments' namespace with a 7200-second TTL and a 60-second lease so no other agent accidentally fires a second transfer for the same order.”
Exactly-once email notification in multi-agent pipeline
“I need to make sure only one agent sends the welcome email to user@example.com — can you claim the key 'welcome-email-user-12345' in namespace 'notifications' with a 24-hour TTL so every other agent that tries the same key just gets the already-recorded result?”
Distributed task lock for scheduled job
“Claim the action key 'nightly-report-2024-07-15' in the 'reports' namespace with a 3600-second TTL and a 300-second lease so only one worker runs tonight's report generation even if multiple agents wake up at the same time.”
Technical details
Endpoint
GEThttps://agentic-endpoints-testnet.oliver-835.workers.dev/once-keyWhen to prefer
Choose this endpoint when you need atomic exactly-once semantics for a side-effectful action in a distributed or multi-agent system — especially for payments, notifications, or task dispatch where duplicate execution is harmful. Prefer it over application-level deduplication when you need cross-agent coordination, replay of recorded results to late callers, and optional lease-based abandonment recovery.
Side effects
- Key already claimed by another caller — returns the previously recorded result instead of a new claim
- Missing or invalid namespace_token on a subsequent request to an existing namespace — returns 401/403
- Lease expired before /once-key/complete was called — claim abandoned and key becomes reclaimable
- Invalid or missing action_key — returns 400 bad request
- payload_sha256 mismatch detected — returns conflict error to signal differing payloads for same key
- Network timeout causing uncertainty about whether claim was registered — agent should retry and check replay response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| ttl | number | Claim lifetime in seconds (default 86400) |
| lease_ttl | number | Seconds you have to call /once-key/complete before the claim is treated as abandoned and another caller may take it over. Omit to hold the claim for its full ttl. |
| namespace | string | Isolation scope for the claimed key |
| action_key | string | Unique key to claim exactly once |
| payload_sha256 | string | Optional hash of the payload for conflict detection |
| namespace_token | string | Owner token issued on the first claim in a namespace; required on every later request |
Tags
x402
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