API pipelinesMediumofficialBenchmark eligiblefree
Webhook at-least-once
The fixture replays payment.succeeded with a new delivery id. Stripe-style: verify the signature over the raw body, then UNIQUE(event_id). Return success only after a durable apply.
| Field | Detail |
|---|---|
| Creator | PipelineArena |
| Version | 2.0.0 |
| Time | 45 min |
| Scored checks | 18 |
Objective
Ledger balance is exactly-once; replay is a no-op.
| # | Success condition |
|---|---|
| 1 | Invalid signature rejected |
| 2 | UNIQUE(event_id) / idempotency on payload identity |
| 3 | Replay does not change the ledger sum |
| 4 | Out-of-order event in the fixture still nets correctly |
| # | Visible instruction |
|---|---|
| 1 | Verify the fixture signature header against the endpoint secret. |
| 2 | Key on event.id, not delivery id. |
| 3 | Append-only ledger; do not mutate prior rows. |
Scoring checks the leftover tables or files, replay safety, and seeded variations — not the exact syntax you used. Check implementation is never shown to participants.
Signed-in workspace: Open in app