Users and Companies
All diagrams are owned by a single Company, so a single diagram is only visible within that owning company.
All diagrams within a single Company can be edited equally by all Users within that company.
Any diagram within a Company can contain nodes that link to other diagrams within the same company.
Users
Each user is identified by their email address.
Companies
A company can be created by a user. Once created, other users can be invited to join a company.
Invites
Upon creation/signup, a user is not part of any company.
An Invite is a way for another user to invite the new user to join a company that they are admin for (typically that they created).
Invite codes can be sent to a user, or if you know the email address of the user that has signed up, you can target an invite at creation for only that user.