Allura allows for very fine grained access control options over your projects which can be a bit confusing when starting a new project. Mainly there are two places where you can fine tune the access permissions to a project (in reverse order of priority).

1. Project User permissions
2. Tool specific permissions

Where (1.) defines the user groups for a project and the more general permissions for the users inside the group. And (2.) overrides (1.) with per tool/content permissions.

Project User permissions

To reach the general project user permissions follow this list of steps (starting at the sidebar)

1. Admin (top sidebar)
2. User Permissions (bottom sidebar)

You should now be able to add users to the groups and define the generic permissions for the project

Tool specific permissions

Some tools have per-tool (repositories, issue tracker, links) permissions that override the project permissions. To see the the permissions for an individual tool:

1. Admin (top sidebar)
2. Tools (bottom sidebar)
3. Press Permissions in the tool you want from the main page

This will present you permissions for that given tool. Keep in mind that these permissions may override the more general ones set in the general project user permissions - that way you can have a private project with a select public tools.

A quick note on subproject

Subprojects inherit the user groups from the original project. So if you want to change the general permissions for a subproject, you will be able to do it Permissions tab for that subproject. But if you want to add a new user or group to the project you should go to the User Permissions tab in the parent project.

A final warning on making permission more strict

When closing up a project (i.e. making it more private) keep in mind that the project cannot guess your intended outcome for the individual tools. So if you change the project permissions to be more strict, you still need to do it for each tool.

The Private project option in the project creation interface exists to automate this process, but it only works when creating a new project.