auth-architecture {Architecture} (v1.0)

"Auth is not a feature. It's the foundation."

Purpose

Designs authentication and authorization architecture using Firebase Auth. Covers provider selection, custom claims for RBAC, session management, and MFA. [EXPLICIT] When to use: Setting up auth for any Firebase project.

Core Principles

1. Law of Claims: Use custom claims for roles (admin, editor, viewer). Set via Admin SDK. [EXPLICIT]
2. Law of Rules: Firestore Security Rules read request.auth.token claims for authorization. [EXPLICIT]
3. Law of Providers: Start with email/password + Google. Add others as needed. [EXPLICIT]

Core Process

Phase 1: Select auth providers based on user requirements.

Phase 2: Design role hierarchy and custom claims structure.

Phase 3: Design Security Rules that enforce claims. Configure MFA if required.

Validation Gate

• Auth providers selected and documented
• Custom claims structure defined
• Security Rules enforce claims
• Session management strategy documented

Usage

Example invocations:

• "/auth-architecture" — Run the full auth architecture workflow
• "auth architecture on this project" — Apply to current context

Assumptions & Limits

• Assumes access to project artifacts (code, docs, configs) [EXPLICIT]
• Requires English-language output unless otherwise specified [EXPLICIT]
• Does not replace domain expert judgment for final decisions [EXPLICIT]

Edge Cases

Scenario	Handling
Empty or minimal input	Request clarification before proceeding
Conflicting requirements	Flag conflicts explicitly, propose resolution
Out-of-scope request	Redirect to appropriate skill or escalate