{
  "id": 8636860,
  "title": "I Built a Spring Boot Starter to Handle Duplicate API Requests",
  "url": "https://urgent.news/2026/09/20/i-built-a-spring-boot-starter-to-handle-duplicate-api-requests",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-09-20T07:24:07.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/irosh-perera/i-built-a-spring-boot-starter-to-handle-duplicate-api-requests-2m4j"
  },
  "original_language": "en",
  "account": "A developer has created a Spring Boot library to manage duplicate requests to APIs. When a server processes a request like creating an order, it might not receive a response back to the client before the connection is lost. The client will then resend the request, which could lead to the server creating duplicate orders. This is where the open-source Idempotency Starter comes in.\n\nIdempotency refers to an API operation where repeating the same logical request does not cause additional side effects. An idempotency key allows the client to identify the request that was made. If the client retries, the same key can be used to avoid creating a new order. The starter provides an annotation for protected endpoints, a request header for the key, validation of the request body hash, and options for caching and replaying completed responses.\n\nTo use it, first add the Maven dependency, then annotate the endpoint with @Idempotent. Configure the starter in application.yml to choose between in-memory or Redis storage, set the header name, default expiry time and timeout, and decide whether to reject requests with a different hash. Then send a request with the Idempotency-Key header. If the same key is used again, the server will return the saved response rather than executing the controller a second time.\n\nFor production, consider the key's limited lifetime, choosing an appropriate storage option, and ensuring the storage is part of a distributed solution with proper testing. The library is open source under the MIT License, welcomes feedback, and has plans for additional storage options, locking improvements, and tests. The developer asks how others handle duplicate requests in their Spring Boot applications.",
  "summary": "A client sends a request to create an order. The server processes it, but the connection drops before the response reaches the client. The client retries. How can the API recognise that retry and avoid creating another order? This is the problem my open-source Spring Boot Idempotency Starter aims to address. What is idempotency? For an API operation, idempotency means that repeating the same…",
  "key_points": [
    "Developer creates Idempotency Starter library for Spring Boot",
    "Idempotency key prevents duplicate API requests",
    "Starter supports in-memory or Redis storage configuration"
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}