User Approval

User approval extension for Caffeine AI.

Overview

This skill adds approval-based user management. Users request access; admins approve or reject. Approved users gain access to protected features.

Prerequisite: You must follow extension-authorization first, as this integration depends on it.

Backend

Module API

The prefabricated module mo:caffeineai-user-approval/approval provides low-level approval state management. Do not modify it.

import AccessControl "mo:caffeineai-authorization/access-control";

module {
    public type ApprovalStatus = {
        #approved;
        #rejected;
        #pending;
    };

    public type UserApprovalState = { /* internal state */ };

    public func initState(accessControlState: AccessControl.AccessControlState) : UserApprovalState;

    public func isApproved(state : UserApprovalState, caller : Principal) : Bool;
    public func requestApproval(state : UserApprovalState, caller : Principal);
    public func setApproval(state : UserApprovalState, user : Principal, approval : ApprovalStatus);

    public type UserApprovalInfo = {
        principal : Principal;
        status : ApprovalStatus;
    };

    public func listApprovals(state : UserApprovalState) : [UserApprovalInfo];
}

Setup in main.mo

include MixinUserApproval(accessControlState, approvalState) MUST be placed in main.mo, not in a custom mixin file. Declare approvalState at actor top level and pass it into the mixin. The mixin provides these public endpoints automatically:

• isCallerApproved()
• requestApproval()
• setApproval(user, status)
• listApprovals()

Keep approvalState in scope for custom approval guards in app-specific endpoints.

Do NOT redeclare any of the mixin-provided functions.

import AccessControl "mo:caffeineai-authorization/access-control";
import MixinAuthorization "mo:caffeineai-authorization/MixinAuthorization";
import MixinUserApproval "mo:caffeineai-user-approval/MixinUserApproval";
import UserApproval "mo:caffeineai-user-approval/approval";
import Runtime "mo:core/Runtime";

actor {
    let accessControlState : AccessControl.AccessControlState;
    include MixinAuthorization(accessControlState, null);
    let approvalState : UserApproval.UserApprovalState;
    include MixinUserApproval(accessControlState, approvalState);

    // Example custom endpoint with an approval guard:
    // public shared ({ caller }) func protectedFeature() : async () {
    //     if (not (UserApproval.isApproved(approvalState, caller) or AccessControl.hasPermission(accessControlState, caller, #admin))) {
    //         Runtime.trap("Unauthorized: Only approved users can perform this action");
    //     };
    // };
};

The migration chain head — UserApproval.initState depends on the access-control state, so compute it in order inside the migration body:

import AccessControl "mo:caffeineai-authorization/access-control";
import UserApproval "mo:caffeineai-user-approval/approval";

module {
    type NewActor = {
        accessControlState : AccessControl.AccessControlState;
        approvalState : UserApproval.UserApprovalState;
    };

    public func migration(_old : {}) : NewActor {
        let accessControlState = AccessControl.initState();
        {
            accessControlState;
            approvalState = UserApproval.initState(accessControlState);
        };
    };
};

On initState, existing admins are automatically approved. All other users are pending.

IMPORTANT: Apply the right authorization and/or approval check to each custom public function.

Frontend

Approval-based user management:

User Approval Flow

• Check approval status (isCallerApproved)
• If not approved, show option to request approval (requestApproval)
• Block access to main features for non-approved users
• Admins have access to all features of the application
• Display approval status clearly in the UI

Admin Dashboard

For admin users, provide a dashboard to:

• List all users with their approval status (listApprovals)
• Approve or reject users (setApproval)
• View and assign user roles (using getCallerUserRole and assignCallerUserRole)

Backend Integration

The backend already implements the following functionality. The full interface can be found in <backend-interface>

// Check if current user is approved, admins are always approved isCallerApproved(): Promise<boolean>;

// Submit approval request requestApproval(): Promise<void>;

// Get all users and their approval status (admin only) listApprovals(): Promise<Array<UserApprovalInfo>>;

// Approve or reject a user (admin only) setApproval(user: Principal, status: ApprovalStatus): Promise<void>;

// Assign a role to a user (admin only) assignCallerUserRole(user: Principal, role: UserRole): Promise<void>;

// Get current role for a specific user getCallerUserRole(): Promise<UserRole>;