Compiled REST-API always returns 302

I think your issue might be different. From the latest version of the REST API Plugin readme in GitHub:

Important Step: To enable the plugin make sure to set the system property adminConsole.access.allow-wildcards-in-excludes to true

Without the above step the REST API plugin always redirects to login. This was done in response to a security issue.

I’ll sort a release to get that new readme bundled.