firebase-architecture {Architecture} (v1.0)

"Firebase is the platform. Architecture is how you use it without hitting walls."

Purpose

Designs complete Firebase project architecture covering Firestore data model, Cloud Functions topology, Hosting configuration, Security Rules strategy, and service integration patterns. [EXPLICIT] When to use:

• Starting a new Firebase project
• Redesigning an existing Firebase architecture
• When /jm:design-architecture targets Firebase

Core Principles

1. Law of Denormalization: Firestore rewards reading over writing. Model for your queries, not your entities. [EXPLICIT]
2. Law of Triggers: Cloud Functions react to events. Design event chains, not request chains. [EXPLICIT]
3. Law of Rules: Security Rules are your last line. Design them BEFORE implementation. [EXPLICIT]

Core Process

Phase 1: Service Selection

1. Map FR-XXX requirements to Firebase services (Auth, Firestore, Functions, Hosting, Storage). [EXPLICIT]
2. Identify Google Cloud services needed (Cloud Tasks, Pub/Sub, Secret Manager). [EXPLICIT]
3. Identify third-party integrations (Algolia, SendGrid, Stripe). [EXPLICIT]

Phase 2: Architecture Design

1. Design Firestore collection hierarchy (top-level collections, subcollections, composite indexes). [EXPLICIT]
2. Design Cloud Functions topology (HTTP triggers, Firestore triggers, Auth triggers, scheduled). [EXPLICIT]
3. Design Security Rules strategy (role-based via custom claims, resource-based). [EXPLICIT]
4. Design Hosting config (rewrites for SPA, headers, preview channels). [EXPLICIT]
5. Produce C4 context and container diagrams (Mermaid). [EXPLICIT]

Phase 3: Document

1. Write architecture document with service matrix. [EXPLICIT]
2. Create ADR for significant decisions. [EXPLICIT]
3. Estimate Firebase costs (reads/writes/invocations). [EXPLICIT]

3. Inputs / Outputs

Input	Type	Required	Description
spec.md or requirements	File/Text	Yes	What to build
Output	Type	Description
--------	------	-------------
Architecture document	Markdown	C4 diagrams + service matrix
ADR	File	Key decisions

Validation Gate

• All FR-XXX mapped to Firebase services
• Firestore schema designed for query patterns
• Security Rules strategy documented
• C4 diagrams produced (Mermaid)
• No AWS/Azure references (R-002)

5. Self-Correction Triggers

[!WARNING] IF designing SQL-style normalized schema THEN STOP. Firestore requires denormalization. IF adding Docker/K8s to architecture THEN STOP. Use Firebase Hosting + Hostinger (R-003).

Usage

Example invocations:

• "/firebase-architecture" — Run the full firebase architecture workflow
• "firebase 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