SOLID C# - 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 .NET 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/Contracts/ - 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 | |-------|----------|-----------| | Controllers | Modules/[Feature]/Controllers/ | 50 | | Services | Modules/[Feature]/Services/ | 100 | | Repositories | Modules/[Feature]/Repositories/ | 100 | | Contracts | Modules/[Feature]/Contracts/ | 30 | | Models | Modules/[Feature]/Models/ | 50 | | Shared | Core/{Services,Contracts,Models}/ | - |
NEVER use flat structure - always Modules/[Feature]/
Critical Rules (MANDATORY)
| Rule | Value | |------|-------| | File limit | 100 lines (split at 90) | | Controllers | < 50 lines, delegate to services | | Interfaces | Contracts/ directory ONLY | | XML docs | Every public member documented | | DI | Use Microsoft.Extensions.DependencyInjection | | Small interfaces | 1-3 members max | | Records | Prefer record for DTOs and value objects |
Reference Guide
| Topic | Reference | When to consult | |-------|-----------|-----------------| | SOLID Principles | [principles.md](references/principles.md) | Quick reference for all 5 principles | | Patterns & Structure | [patterns.md](references/patterns.md) | Directory layout, testing, records |
Forbidden
| Anti-Pattern | Fix | |--------------|-----| | Files > 100 lines | Split at 90 | | Interfaces in impl files | Move to Contracts/ directory | | Fat interfaces (4+ members) | Split into focused interfaces | | Flat project structure | Use Modules/[Feature]/ | | new for dependencies | Use constructor injection + DI | | Service Locator pattern | Use constructor injection |