Agent skill · affaan-m
codebase-onboarding
Analyze an unfamiliar codebase and generate a structured onboarding guide with architecture map, key entry points, conventions, and a starter CLAUDE.md. Use when joining a new project or setting up Claude Code for the first time in a repo.
What it needs
About 5k tokens when loaded.
What this skill does
Codebase Onboarding Systematically analyze an unfamiliar codebase and produce a structured onboarding guide. Designed for developers joining a new project or setting up Claude Code in an existing repo for the first time. When to Use First time opening a project with Claude Code Joining a new team or repository User asks "help me understand this codebase" User asks to generate a CLAUDE.md for a project User says "onboard me" or "walk me through this repo" How It Works Phase 1: Reconnaissance Gather raw signals about the project without reading every file. Run these checks in parallel: Phase 2: Architecture Mapping From the reconnaissance data, identify: Tech Stack Language(s) and version constraints Framework(s) and major libraries Database(s) and ORMs Build tools and bundlers CI/CD platform Architecture Pattern Monolith, monorepo, microservices, or serverless Frontend/backend split or full-stack API style: REST, GraphQL, gRPC, tRPC Key Directories Map the top-level directories to their purpose: <!-- Example for a React project — replace with detected directories --> Data Flow Trace one request from entry to response: Where does a request enter? (router, handler, controller) How is it validated? (middleware, schemas, guards) Where is business logic? (services, models, use cases) How does it reach the database? (ORM, raw queries, repositories) Phase 3: Convention Detection Identify patterns the codebase already follows: Naming Conventions File naming: kebab-case, camelCase, PascalCase, snakecase Component/class naming patterns Test file naming: .test.ts, .spec.ts, test.go Code Patterns Error handling style: try/catch, Result types, error codes Dependency injection or direct imports State management approach Async patterns: callbacks, promises, async/await, channels Git Conventions Branch naming from recent branches Commit message style from recent commits PR workflow (squash, merge, rebase) If the repo has no commits yet or only a shallow history (e.g. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills affaan-m/codebase-onboarding--cd3dd2