## What this teaches

How to preflight (OPTIONS) Requests Fail even with CORs set.

## The problem

Issue flipt-io/flipt#4620 (closed, 12 comments): The OPTIONS request does not supply the same CORS settings as the GET request does which means flipt-web fail. (IPs are all internal resources so I left them as is) Yaml Config ``` cors: enabled: true ``` GET request ``` * Preparing request to http://CONTAINER_IP:3524/internal/v1/evaluation/snapshot/namespace/iris * Current time is 2025-08-28T20:25:02.535Z * Enable automatic URL encoding * Using default HTTP version * Disable SSL validation * Enable cookie sending with jar of 24 cookies * Connection 17 seems to be dead * Closing connection 17 * Hostname in DNS cache was stale, zapped * Trying 1

## What worked (verified answer)

Preflight (OPTIONS) requests failing on Flipt v2 with CORS set: that was a bug in the v2 beta builds, fixed in the release versions. Upgrade from the beta to the latest v2 release (non-beta).

## Source

gh:flipt-io/flipt#4620 - https://github.com/flipt-io/flipt/issues/4620