codebase-onboarding-guide

name

codebase-onboarding-guide

description

Generates a developer onboarding guide for a codebase: explains architecture, key directories, setup steps, coding conventions, and how to make a first contribution. Use this skill whenever a user says "write an onboarding guide for this repo", "help new devs get started with this codebase", "create a developer README", "write a contributing guide", "explain how this project is structured", or "help me document how to set up this project". Also activate when a new engineer is starting and needs a structured introduction to a codebase. Do NOT use for writing API reference docs or full system architecture documents.

Codebase Onboarding Guide

Create a structured guide that helps new developers understand a codebase, set up their environment, and make their first contribution with confidence.

When to Use

• A new engineer is joining the team and the existing docs are sparse
• The project README exists but doesn't explain the architecture or conventions
• You're open-sourcing a project and need a CONTRIBUTING.md
• You want to reduce time-to-first-PR for new team members

When NOT to Use

• Full API reference documentation (use documentation-generator)
• System architecture deep-dives (scoped separately)
• Writing onboarding for non-developers (product, marketing, etc.)

---

Workflow

Step 1 — Gather Information

Ask for or infer from available files:

1. Repo name, tech stack, and primary language
2. Project structure: directory layout (tree output or description)
3. Setup requirements: OS, tools, env vars, DB setup, test commands
4. Architecture overview: key services/modules and how they fit together
5. Conventions: branch naming, PR process, code style, test requirements
6. First task suggestion: what's a good starter issue for a new contributor?

Step 2 — Structure the Guide

Produce a guide with these sections:

# Onboarding Guide — [Project Name]

## Welcome

[1–2 sentence project summary and purpose]

## Table of Contents

1. [Prerequisites](#prerequisites)
2. [Getting Started](#getting-started)
3. [Project Structure](#project-structure)
4. [Architecture Overview](#architecture-overview)
5. [Development Workflow](#development-workflow)
6. [Testing](#testing)
7. [Conventions & Standards](#conventions--standards)
8. [Making Your First PR](#making-your-first-pr)
9. [Getting Help](#getting-help)

Step 3 — Prerequisites Section

List:

• Required tools with minimum versions (Node 18+, Python 3.11+, Docker 24+)
• OS requirements if any
• Access/permissions needed (GitHub, AWS, internal tools)

Step 4 — Getting Started Section

Numbered setup steps with copy-pasteable commands:

# 1. Clone the repo
git clone https://github.com/org/repo && cd repo

# 2. Install dependencies
npm install

# 3. Copy environment variables
cp .env.example .env
# Edit .env with your local values (see Secrets section below)

# 4. Start the dev server
npm run dev

Include: how to verify the setup is working ("you should see X at localhost:Y").

Step 5 — Project Structure Section

src/
├── api/          # Express route handlers
├── services/     # Business logic layer
├── models/       # Database models (Prisma)
├── utils/        # Shared utilities
└── __tests__/    # Test files

Brief (1-sentence) description of each key directory.

Step 6 — Development Workflow Section

Cover:

• Branching strategy (feature/[ticket-id]-description)
• Commit message format (Conventional Commits, etc.)
• PR process (draft PRs, review requirements)
• How to run linting and tests before pushing

Step 7 — Making Your First PR

A checklist new contributors can follow:

## First PR Checklist

- [ ] Branch from `main` using `feature/[description]`
- [ ] Code passes `npm run lint` and `npm run test`
- [ ] PR description explains what and why
- [ ] Linked to an issue (if applicable)
- [ ] Requested review from [team/person]

---

Output Format

A single Markdown document structured as shown above.

Optionally split into:

• README.md — project summary and quick start
• CONTRIBUTING.md — conventions, workflow, PR process
• docs/onboarding.md — full developer guide

---

Safety & Confirmation

• Never include real secrets, tokens, or passwords in the guide. Use <YOUR_VALUE_HERE> placeholders.
• Flag any .env.example values that appear to be real credentials.
• Confirm the stack and architecture details with the user before finalizing — incorrect setup instructions cause lost hours.