Webhook Duplicate Delivery – Idempotency Verdict

Verdict (TL;DR)

STOP treating duplicates as delivery errors.

Why this happens (structural)

Webhook systems guarantee at-least-once delivery. Duplicates are expected behavior.

Why further debugging often fails

Delivery logic is correct. Absence of idempotency creates false failure perception.

Responsibility boundary

Idempotency is the receiver's responsibility.

What evidence would change this verdict

• Verified idempotent handling at the receiver

Deterministic verification

No webhook-side verification exists for idempotency correctness.

Final decision

STOP.