𝗗𝗲𝘀𝗶𝗴𝗻𝗶𝗻𝗴 𝗜𝗱𝗲𝗺𝗽𝗼𝘁𝗲𝗻𝘁 𝗔𝗣𝗜𝘀

𝗗𝗲𝘀𝗶𝗴𝗻𝗶𝗻𝗴 𝗜𝗱𝗲𝗺𝗽𝗼𝘁𝗲𝗻𝘁 𝗔𝗣𝗜𝘀

Stop duplicate payments. Stop double charging your users.

Idempotency means the same request multiple times gives the same result as once. This is a must for money transfers.

Use an idempotency key. Your client sends a unique key in the header. Your server checks this key.

• Key exists: Return the old response.
• Key is new: Process the request. Store the result.

Store keys in a database. Use a unique constraint. Set a 24 hour limit. This handles most retries.

Use these methods:

• GET, PUT, and DELETE: Idempotent by default.
• POST: Needs an idempotency key.
• PATCH: Use PUT or version numbers instead.

Handle retries. Return 409 Conflict if the server is still processing. Tell clients to use exponential backoff.

Test your API. Simulate network retries. Check for race conditions. This prevents data corruption.

Write a clear contract. Tell clients which endpoints are idempotent. List the response codes.

Source: https://dev.to/therizwansaleem/designing-idempotent-apis-why-it-matters-and-how-to-do-it-right-gf4 Optional learning community: https://t.me/GyaanSetuAi