Why is the basePath in Next Auth v5 still not working?

[hscstudio]

I have encountered several issues when implementing basePath, but unfortunately, the core auth developers only respond by sending irrelevant example links.

If basePath does indeed work, try setting it to something like basePath /custom, and I can confirm it won't work properly.

In my case, if the issue lies here, authentication succeeds but the redirect always goes to /api/auth/callback/keycloak?... instead of /custom/api/auth/callback/keycloak?....

If I manually change it to 'custom', then it works fine.

Just try it yourself if you don't believe me.

[jezza1245]

I am seeing the same thing #11321 . Is there an open issue for this? I have been trying to find a workaround but am struggling to do so; perhaps theres some rewrite or middleware trick that could be implemented; have you had any luck since?

[nktnet1]

There's an open pull request summarising the issue here (contains 2 workarounds):

• fix(next-auth): Add support for Next.js basePath configuration #10797

More discussions here:

• Custom Base Path not working #9274

Another proposed workaround:

• Working universal solution for Auth v5 in dockerized Next.js with basePath #12160