Harden idempotency key design
Hard APIs arena: safe retries, request hashes, and conflict responses
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Missing prerequisites: apis-easy-idempotency-key
Checkout retries sometimes create duplicate charges after client timeouts. You are working inside an API platform team, and the arena only clears when the result is safe, deterministic, and explainable.
Learn to apply safe retries, request hashes, and conflict responses in an API platform team while explaining the invariant, safety constraints, and hidden edge cases.
- Demonstrates safe retries, request hashes, and conflict responses
- Handles the visible sample and hidden edge cases
- Keeps output deterministic and explainable
- Avoids unsafe dynamic execution
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