I recently came across idempotency keys while working with APIs, and I’m trying to understand how people actually use them with AI APIs.
For example, if my backend sends a request to an AI API and the request times out, I might retry it.
But what if the first request was actually processed and I just didn’t receive the response?
Wouldn’t that mean I’ve sent the same request twice?
So I started looking into idempotency keys:
POST /some-ai-endpoint
Idempotency-Key: 550e8400-e29b-41d4-a716-446655440000
But I still have a few questions about the actual implementation.
Should the idempotency key be generated by the frontend or by the backend?
Should I generate a new key for every request?
What happens if the same key is accidentally used with a different request?
And how long is the key normally stored on the server?
I’m mainly interested in how people are handling this in real applications when integrating AI APIs, rather than just the definition of idempotency.
How are you guys implementing this?
Can you specify your use cases?
idempotency features on OpenAI-related specifications are typically handled at the application or integration layer, such as OpenAI’s specialized Agentic Commerce and Checkout APIs rather than individual LLM inference calls.
Thanks, that helps. My use case is more around a backend application calling an OpenAI API and handling retries.
For example, my backend sends a request to an OpenAI model, but the request times out or the connection drops before my application receives the response. I’m trying to understand what the recommended approach is if the application wants to retry that request.
My main questions are:
- How do you distinguish a failed request from a request that was actually processed but whose response wasn’t received?
- Is there an OpenAI-supported way to make such retries idempotent for normal model/inference requests?
- Or is this something that should be handled entirely by the application’s own retry/request-tracking layer?
I’m not specifically referring to Agentic Commerce or Checkout APIs. I’m mainly trying to understand the pattern for a regular backend → OpenAI API integration.
This is better than your original post because now you’re giving them a specific use case and making it clear you’re asking about normal model API calls, not commerce/checkout.
Also, their response gives you a useful clue: don’t assume that “idempotency key” is a general-purpose feature for every OpenAI model request. Your question should specifically ask what the recommended retry pattern is for the type of API call you’re making.
It seems like you are concerned about normal model API calls, correct?
You can set timeouts in the HTTP request header. That’s what I have been doing for a couple of years for many of the OpenAI model APIs. Never had a problem albeit occasional abnormal disruptions which are unavoidable.
If you have a transaction critical use case, you should code a retry mechanism.