Route Handler

Create a single catch-all route to handle all auth endpoints.

app/api/auth/[...authgear]/route.ts

This registers the following endpoints automatically:

Endpoint	Method	Description
`GET /api/auth/login`	GET	Starts the PKCE OAuth flow; redirects to Authgear
`GET /api/auth/callback`	GET	Handles the OAuth callback; sets the session cookie
`GET /api/auth/logout`	GET	Clears the session cookie; redirects to Authgear logout
`GET /api/auth/refresh`	GET	Manually refreshes the access token
`GET /api/auth/userinfo`	GET	Returns the current user as JSON (used by `AuthgearProvider`)

OAuth flow


Browser → GET /api/auth/login
       → 302 to Authgear (with PKCE code_challenge)
       → User authenticates
       → 302 back to /api/auth/callback?code=...&state=...
       → Token exchanged, session cookie set
       → 302 to postLoginRedirectURI (default: "/")