Lost API Responses Are Not Failed Writes: Designing Retries Around Intent

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A server may commit a resource and send a response that never reaches the browser, leaving the client unsure whether anything was created. Retrying with a fresh request identity could therefore produce duplicate resources. The article recommends capturing one operation with a stable idempotency key and serialized payload before the first attempt, and reusing both until the outcome is known. It provides a small JavaScript helper and a test that simulates a committed write whose response is lost. It also explains that the server must durably map each owner and key pair to an operation, comparing input fingerprints to detect conflicting key reuse.

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