Idempotency key best practices for safe POST
POST is not naturally idempotent; APIs use Idempotency-Key to avoid duplicate charges or side effects. Keys should be unique per logical operation, stable on client retries, and often UUID-shaped.
Common causes
- Reusing one key for different payloads.
- Missing key on retried POST.
- Invalid format rejected by the API gateway.
How to fix
- Generate UUID v4 per operation.
- Validate header format with Idempotency Key Checker.
- Store key → result mapping for the TTL.
Use our tool
Check idempotency keyRelated