aif-architecture

name	aif-architecture
description	Generate architecture guidelines for the project. Analyzes tech stack from DESCRIPTION.md, recommends an architecture pattern, and creates .ai-factory/ARCHITECTURE.md. Use when setting up project architecture, asking "which architecture", or after $aif setup.
argument-hint	[clean|ddd|microservices|monolith|layers]
allowed-tools	Read Write Glob Grep Bash(mkdir *) AskUserQuestion Questions
disable-model-invocation	false

Architecture - Generate Architecture Guidelines

Generate .ai-factory/ARCHITECTURE.md with architecture decisions tailored to the project.

Workflow

Step 0: Load Config & Project Context

FIRST: Read .ai-factory/config.yaml if it exists to resolve:

• Paths: paths.description and paths.architecture
• Language: language.ui for prompts and language.artifacts for generated architecture content

If config.yaml doesn't exist, use defaults:

• DESCRIPTION.md: .ai-factory/DESCRIPTION.md
• ARCHITECTURE.md: .ai-factory/ARCHITECTURE.md
• Language: en (English)

THEN: Read .ai-factory/DESCRIPTION.md (use path from config) if it exists to understand:

• Tech stack (language, framework, database, ORM)
• Project size and complexity
• Core features and requirements
• Non-functional requirements

If .ai-factory/DESCRIPTION.md does not exist:

⚠️  No project description found.

Run $aif first to set up project context, or describe your project manually:
- What are you building?
- Tech stack (language, framework, database)?
- Team size?
- Expected scale?

Allow standalone usage — if user provides manual input, use that instead.

Read .ai-factory/skill-context/aif-architecture/SKILL.md — MANDATORY if the file exists.

This file contains project-specific rules accumulated by $aif-evolve from patches, codebase conventions, and tech-stack analysis. These rules are tailored to the current project.

How to apply skill-context rules:

• Treat them as project-level overrides for this skill's general instructions
• When a skill-context rule conflicts with a general rule written in this SKILL.md, the skill-context rule wins (more specific context takes priority — same principle as nested CLAUDE.md files)
• When there is no conflict, apply both: general rules from SKILL.md + project rules from skill-context
• Do NOT ignore skill-context rules even if they seem to contradict this skill's defaults — they exist because the project's experience proved the default insufficient
• CRITICAL: skill-context rules apply to ALL outputs of this skill — including the ARCHITECTURE.md template. The template in this SKILL.md is a base structure. If a skill-context rule says "architecture doc MUST include X" or "MUST cover section Y" — you MUST augment the template accordingly. Generating ARCHITECTURE.md that violates skill-context rules is a bug.

Enforcement: After generating any output artifact, verify it against all skill-context rules. If any rule is violated — fix the output before presenting it to the user.

Step 1: Analyze & Recommend

Based on project context, evaluate against the decision matrix and recommend an architecture:

If $ARGUMENTS specifies an architecture (e.g., $aif-architecture clean):

• Use that architecture directly, skip to Step 2

If no specific architecture requested:

• Evaluate the project against the decision matrix (see Knowledge Base below)
• Consider: team size, domain complexity, scale requirements, tech stack
• Present recommendation via AskUserQuestion:

Based on your project context:
- [reason 1 from project analysis]
- [reason 2 from project analysis]

Which architecture pattern should we use?

1. [Recommended pattern] (Recommended) — [why it fits]
2. [Alternative 1] — [brief reason]
3. [Alternative 2] — [brief reason]
4. [Alternative 3] — [brief reason]

Architecture options:

• Clean Architecture — strict dependency inversion, good for complex business logic
• Domain-Driven Design (DDD) — bounded contexts, good for complex domains with multiple subdomains
• Microservices — independent deployment, good for large teams with clear domain boundaries
• Modular Monolith — single deployment with strong module boundaries, good default for most projects
• Layered Architecture — simple layers (presentation → business → data), good for smaller projects

Step 2: Generate the Architecture Artifact

Create the parent directory for the resolved architecture path if needed.

Generate the resolved architecture artifact (default: .ai-factory/ARCHITECTURE.md) with the following structure, adapted to the project's tech stack and language:

# Architecture: [Pattern Name]

## Overview
[1-2 paragraphs: what this architecture is and why it was chosen for THIS project]

## Decision Rationale
- **Project type:** [from DESCRIPTION.md]
- **Tech stack:** [language, framework]
- **Key factor:** [primary reason for this choice]

## Folder Structure
\`\`\`
[folder structure adapted to the project's tech stack]
[use actual framework conventions — e.g., Next.js app/ dir, Laravel app/ dir, Go cmd/ dir]
\`\`\`

## Dependency Rules
[What depends on what. Inner vs outer layers. Module boundaries.]

- ✅ [allowed dependency direction]
- ❌ [forbidden dependency direction]

## Layer/Module Communication
[How layers or modules communicate with each other]
- [pattern 1]
- [pattern 2]

## Key Principles
1. [Principle 1 — adapted to this project]
2. [Principle 2]
3. [Principle 3]

## Code Examples

### [Example 1 title]
\`\`\`[language]
[code example in the project's language/framework]
\`\`\`

### [Example 2 title]
\`\`\`[language]
[code example showing dependency rule]
\`\`\`

## Anti-Patterns
- ❌ [What NOT to do in this architecture]
- ❌ [Common mistake to avoid]

Rules for generation:

• Adapt ALL examples to the project's language and framework (don't use TypeScript examples for a Go project)
• Use the project's actual conventions (import paths, naming, etc.)
• Keep it practical — focus on rules that affect day-to-day development
• Folder structure should extend from what already exists in the project, not replace it

Step 3: Update DESCRIPTION.md

If the resolved DESCRIPTION.md path exists, add an ## Architecture section (or update if it already exists):

## Architecture
See the configured architecture artifact for detailed architecture guidelines.
Pattern: [chosen pattern name]

Step 4: Update AGENTS.md

If AGENTS.md exists in the project root, add .ai-factory/ARCHITECTURE.md to the "AI Context Files" table:

| .ai-factory/ARCHITECTURE.md | Architecture decisions and guidelines |

Only add if not already present.

Step 5: Confirm

✅ Architecture document generated!

Pattern: [chosen pattern]
File: .ai-factory/ARCHITECTURE.md

Key rules:
- [rule 1]
- [rule 2]
- [rule 3]

All workflow skills ($aif-plan, $aif-implement) will now follow these architecture guidelines.

Artifact Ownership

• Primary ownership: .ai-factory/ARCHITECTURE.md.
• Respect config overrides: write to the resolved architecture path from config.yaml when provided.
• Allowed companion updates: architecture pointer in .ai-factory/DESCRIPTION.md, architecture row in AGENTS.md context table.
• Read-only context: roadmap, rules, research, and plan artifacts unless user explicitly requests otherwise.

---

Knowledge Base

Reference material for architecture evaluation and generation. This content informs the generation — it is NOT output directly.

Decision Matrix

Factor	Layered	Clean Architecture	Modular Monolith	DDD	Microservices
Team size	1-5	1-15	5-30	5-30	20+
Domain complexity	Low	Medium-High	Medium-High	High	High
Scale requirements	Low	Moderate	Moderate-High	Moderate-High	Very High
Deploy independence	❌	❌	Partial	Partial	✅
Initial velocity	✅ Fast	Medium	✅ Fast	Medium	❌ Slow
Operational complexity	✅ Low	✅ Low	✅ Low	Medium	❌ High

Quick Decision Guide

New project, small team? → Modular Monolith or Layered
Complex business logic, many rules? → Clean Architecture
Multiple subdomains, large team? → DDD
Independent scaling + large org? → Microservices
Simple CRUD app? → Layered Architecture
Unclear requirements? → Start simple, refactor when patterns emerge

Clean Architecture

Core Principle: Dependencies point inward. Inner layers know nothing about outer layers.

┌─────────────────────────────────────────────────────────┐
│                    Frameworks & Drivers                  │
│  ┌─────────────────────────────────────────────────┐    │
│  │              Interface Adapters                  │    │
│  │  ┌─────────────────────────────────────────┐    │    │
│  │  │           Application Layer              │    │    │
│  │  │  ┌─────────────────────────────────┐    │    │    │
│  │  │  │         Domain Layer            │    │    │    │
│  │  │  │    (Entities & Business Rules)  │    │    │    │
│  │  │  └─────────────────────────────────┘    │    │    │
│  │  └─────────────────────────────────────────┘    │    │
│  └─────────────────────────────────────────────────┘    │
└─────────────────────────────────────────────────────────┘

Folder Structure (TypeScript example):

src/
├── domain/                 # Core business logic (no dependencies)
│   ├── entities/
│   ├── value-objects/
│   └── repositories/       # Interfaces only
├── application/            # Use cases (depends on domain)
│   ├── use-cases/
│   └── services/
├── infrastructure/         # External concerns (implements interfaces)
│   ├── database/
│   ├── external/
│   └── config/
└── presentation/           # UI/API layer
    ├── api/
    ├── controllers/
    └── dto/

Dependency Rules:

• Domain → nothing (pure business logic)
• Application → Domain only
• Infrastructure → Application + Domain (implements interfaces)
• Presentation → Application (calls use cases)

Domain-Driven Design (DDD)

Core Principle: Software structure mirrors the business domain. Bounded contexts define clear boundaries.

Strategic Patterns:

• Bounded Contexts: explicit boundaries around domain models
• Context Mapping: how contexts communicate (Shared Kernel, Customer/Supplier, Anti-Corruption Layer)

Tactical Patterns:

• Entities: identity-based objects
• Value Objects: immutable, equality by value
• Aggregates: consistency boundaries (all invariants enforced through aggregate root)
• Domain Events: communicate state changes between contexts

Folder Structure (TypeScript example):

src/
├── contexts/
│   ├── ordering/
│   │   ├── domain/         # Entities, VOs, events, repository interfaces
│   │   ├── application/    # Use cases, command/query handlers
│   │   ├── infrastructure/ # Repository implementations, external adapters
│   │   └── api/            # HTTP handlers, DTOs
│   ├── inventory/
│   │   └── ...
│   └── shipping/
│       └── ...
└── shared/
    └── kernel/             # Shared base classes, interfaces

Microservices

When to Use:

• Large teams needing independent deployment
• Different scaling requirements per service
• Polyglot persistence needs

When NOT to Use:

• Small team (< 10 people)
• Unclear domain boundaries
• Startups exploring product-market fit

Communication Patterns:

• Synchronous (HTTP/gRPC): queries, real-time validation
• Asynchronous (Events/Messages): side effects, eventual consistency

Data Patterns:

• Database per Service
• Saga Pattern for distributed transactions

Modular Monolith

Core Principle: Single deployment unit with strong module boundaries. Best of both worlds — simple ops, future extraction ready.

Folder Structure (TypeScript example):

src/
├── modules/
│   ├── users/
│   │   ├── api/           # HTTP handlers
│   │   ├── domain/        # Business logic
│   │   ├── infra/         # Database, external
│   │   └── index.ts       # Public API only
│   ├── orders/
│   │   └── ...
│   └── payments/
│       └── ...
├── shared/                 # Truly shared code
│   ├── kernel/
│   └── utils/
└── main.ts                # Composition root

Module Communication Rules:

• Modules expose explicit public API via index file
• Other modules use ONLY the public API
• Never reach into module internals

Layered Architecture

Core Principle: Separate concerns into horizontal layers. Each layer only depends on the layer directly below it.

Folder Structure (TypeScript example):

src/
├── routes/                # Presentation layer (HTTP handlers)
├── controllers/           # Request/response handling
├── services/              # Business logic layer
├── models/                # Data models
├── repositories/          # Data access layer
└── utils/                 # Cross-cutting utilities

Dependency Rules:

• Routes → Controllers → Services → Repositories → Database
• No skipping layers (routes should not call repositories directly)