fusengine SOLID Python - Modular Architecture
Agent Workflow (MANDATORY)
Before ANY implementation, use TeamCreate to spawn 3 agents:
- fuse-ai-pilot:explore-codebase - Analyze existing architecture
- fuse-ai-pilot:research-expert - Verify Python docs via Context7
- fuse-ai-pilot:sniper - Post-implementation validation
DRY - Reuse Before Creating (MANDATORY)
Before writing ANY new code:
- Grep the codebase for similar interfaces, services, or logic
- Check shared locations:
core/services/,core/interfaces/ - If similar code exists -> extend/reuse instead of duplicate
- If code will be used by 2+ features -> create it in
core/
Architecture (Modules MANDATORY)
| Layer | Location | Max Lines |
|---|---|---|
| Routes | modules/[feature]/routes/ |
50 |
| Services | modules/[feature]/services/ |
100 |
| Repositories | modules/[feature]/repositories/ |
100 |
| Interfaces | modules/[feature]/interfaces/ |
30 |
| Models | modules/[feature]/models/ |
50 |
| Shared | core/{services,interfaces,models}/ |
- |
NEVER use flat src/ structure - always modules/[feature]/
Critical Rules (MANDATORY)
| Rule | Value |
|---|---|
| File limit | 100 lines (split at 90) |
| Routes | < 50 lines, delegate to services |
| Interfaces | interfaces/ directory ONLY |
| Docstrings | Every public function documented |
| Type hints | MANDATORY on all signatures |
| Protocols | Use typing.Protocol for interfaces |
| Small interfaces | 1-3 methods max |
Reference Guide
| Topic | Reference | When to consult |
|---|---|---|
| SOLID Principles | principles.md | Quick reference for all 5 principles |
| Patterns & Structure | patterns.md | Directory layout, testing, typing |
Forbidden
| Anti-Pattern | Fix |
|---|---|
| Files > 100 lines | Split at 90 |
| Interfaces in impl files | Move to interfaces/ directory |
| Fat interfaces (4+ methods) | Split into small Protocols |
Flat src/ structure |
Use modules/[feature]/ |
| Concrete dependencies | Use Protocol + dependency injection |
| Missing type hints | Add type annotations to all signatures |