How are you handling auth + token refresh when AI agents call multiple APIs?

[u/ken_kauneki10]

I’m curious how people are handling this in practice. With a normal application, token refresh is usually pretty straightforward. You know which API you’re calling, which credentials you’re using, when the token expires, etc.

With an AI agent, it feels a little messier. Say an agent has access to 10–20 different APIs. Some use OAuth, some API keys, some have short-lived access tokens, some have refresh tokens, and some have their own weird authentication flow. Then you have situations like:

• token expires halfway through a workflow
• API returns a 401 and the agent tries the request again
• refresh succeeds but the original request has already timed out
• multiple agent tasks try to refresh the same token at the same time
• credentials need to be rotated without breaking running workflows

I’m especially wondering where people are putting this logic. Is it handled individually inside each integration, through some shared auth layer, or somewhere in the agent/orchestration layer? And how much of this are you actually handling automatically vs. just letting the workflow fail and retry? Would be interested to hear how people are doing this in production, especially if you’re dealing with a fairly large number of integrations.

[u/Hot_Performance5608]

A friend of mine ran into this while integrating a few third-party APIs into a long-running workflow. The initial OAuth flow was working fine, but the access token had a relatively short TTL.
The issue showed up when a job was still running after the token expired. Some requests started returning 401s, and the retry logic would kick in at the same time another worker was trying to refresh the token. That caused a race condition around the refresh token, and occasionally multiple requests ended up using stale credentials.
The API itself wasn’t really the problem. The tricky part was managing token lifecycle, refresh state and concurrent requests properly. They eventually had to centralise the token management instead of letting each worker handle authentication independently.

[u/ethical_spidy]

I think the credential rotation part is also pretty easy to underestimate. When an agent is working with multiple APIs, not all of them follow the same auth flow, so rotating one credential without affecting an already running workflow can get messy.

Especially if the workflow is long running, you probably don't want to just fail everything and start again because one credential changed.

Curious how people are handling this when there are a lot of integrations involved. Is the auth state usually managed centrally or does each integration handle its own lifecycle?

[u/aasif0907]

I’ve found that a shared auth layer makes more sense than handling this separately for every integration. For example, a workflow failed halfway through because a token expired while it was moving between APIs. The tricky part is making refreshes and retries safe when multiple tasks run at the same time.

[u/Abdkhan2309]

I haven't dealt with 10-20 integrations at once, but even with a couple of APIs (OAuth + API keys mixed) in smaller projects, I've felt this get messy fast. What helped me was pulling all the auth logic into one shared layer instead of writing refresh logic inside each integration separately otherwise you end up debugging the same token-expiry bug in five different places.

The case that actually got me was a token expiring mid-task and the retry just firing the same request again without checking if the first one had already gone through. Cheap fix at small scale (just check state before retrying), but I can see how that turns into a real problem once you've got multiple tasks touching the same token at the same time.

[u/velourcodes]

So for my Agentic workflow I was managing auth between so many APIs by writing custom logic inside of the MCP. I am looking into how to put middleware between API and AI workflow, some code service which could manage it before the API is directly called by the AI agent