Feature: Add option to disable user registration/signup on self-hosted instances

[sarices]

It would be useful to have an option to disable new user registration on self-hosted instances.

Use cases:

1. Running Multica for internal team use only
2. Preventing public signups on private deployments
3. Restricting registration to specific email domains (e.g., @company.com)
4. Whitelist specific email addresses

Proposed solution:
Add environment variables:

• ALLOW_SIGNUP=false - disable new user registration
• ALLOWED_EMAIL_DOMAINS=company.com,example.com - restrict to specific domains
• ALLOWED_EMAILS=user1@company.com,user2@company.com - whitelist specific emails

This is a common feature in self-hosted applications (similar to what Paperclip has: paperclipai/paperclip#241).

[Bohan-J]

Noted

[sarices]

Thanks. This would be very useful for self-hosted deployments.

Our use case is a private/internal instance where account creation should be controlled by admins only. Right now, if public signup is always enabled, it creates unnecessary risk and management overhead for self-hosted environments.

A simple solution would be an environment variable or config option, for example:

• DISABLE_SIGNUP=true
  or
• AUTH_ALLOW_REGISTRATION=false

Expected behavior:

• hide/disable the “Sign up” entry in the UI
• block registration at the API level as well, not just frontend
• ideally keep admin-created/invited users working normally

If helpful, this could default to the current behavior, with self-hosters opting out explicitly.

[azaanaliraza]

@Bohan-J
I've opened a PR with the implementation: #1098
Feedback welcome!