| name | onboarding-guide |
| description | Codebase onboarding guide. Activated when starting a new project analysis, requesting systematic codebase understanding, or running /onboard. |
Codebase Onboarding Guide
Systematically understand a new codebase
5-Step Onboarding Process
Step 1: High-Level Overview
| Action | Details |
|---|
| Identify the problem | What does this project solve? |
| Know the users | B2B, B2C, internal tool? |
| Core features | Top 3 features |
| Tech stack | Check package.json, README |
Key files: README.md, package.json, company Wiki/Confluence
Step 2: Get It Running
1. Clone repository
2. Install dependencies (npm install, pip install, etc.)
3. Set up env vars (.env.example)
4. Start dev server
5. Test key features manually
Verify: local run, main features work, tests pass, build succeeds
Step 3: Code Exploration
Exploration order:
1. Find entry points
2. Identify main routes/pages
3. Locate core business logic
4. Trace data flow
Strategy: "Follow one feature end-to-end"
Example: Login feature
- Login button → onClick handler
- Handler → API call
- API → backend controller
- Controller → service logic
- Service → database
- Response → frontend state update
Step 4: Understand Patterns
| Pattern to Identify | What to Look For |
|---|
| Architecture | Layer structure, module boundaries |
| State management | Redux, Zustand, Context, React Query |
| API communication | REST, GraphQL, fetch patterns |
| Error handling | Boundaries, try/catch strategy |
| Testing | Unit, integration, E2E approach |
| Naming conventions | Files, components, variables |
Tips: Review recent PRs, find well-written files as benchmarks, use breakpoints for complex logic
Step 5: Start Contributing
Recommended first tasks:
- Good First Issue labeled issues
- Documentation improvements
- Add tests
- Small bug fixes
- Minor refactoring
Before contributing: understand branch strategy, PR templates, CI/CD pipeline, code review process
Analysis Commands
| Command | Description |
|---|
/analyze | Full codebase structure analysis |
/architecture | Architecture and design pattern analysis |
/dependencies | External dependency analysis |
/conventions | Code convention analysis |
/onboard | Run full onboarding workflow |
Onboarding Notes Template
# [Project Name] Onboarding Notes
## Overview
- Purpose:
- Users:
- Core features:
## Tech Stack
- Frontend:
- Backend:
- Database:
- Infrastructure:
## Architecture
[Diagram or description]
## Key Modules
| Module | Location | Role |
|--------|----------|------|
## Domain Terms
| Term | Meaning |
|------|---------|
## Dev Setup
[Local run instructions]
## Common Commands
- Dev:
- Test:
- Build:
## Notes
- [Team-specific rules]
- [Gotchas]
DO NOT
- Try to understand all code at once (focus on core flows first)
- Struggle alone for too long (ask after 30 min of being stuck)
- Ignore documentation (README, comments, test code are important docs)
- Ignore existing patterns (follow team conventions first)
- Suggest refactoring too early (spend at least 2 weeks understanding first)