Monorepo Navigator

Tier: POWERFUL
Category: Engineering
Domain: Monorepo Architecture / Build Systems

Overview

Navigate, manage, and optimize monorepos. Covers Turborepo, Nx, pnpm workspaces, and Lerna. Enables cross-package impact analysis, selective builds/tests on affected packages only, remote caching, dependency graph visualization, and structured migrations from multi-repo to monorepo. Includes Claude Code configuration for workspace-aware development.

Core Capabilities

• Cross-package impact analysis — determine which apps break when a shared package changes
• Selective commands — run tests/builds only for affected packages (not everything)
• Dependency graph — visualize package relationships as Mermaid diagrams
• Build optimization — remote caching, incremental builds, parallel execution
• Migration — step-by-step multi-repo → monorepo with zero history loss
• Publishing — changesets for versioning, pre-release channels, npm publish workflows
• Claude Code config — workspace-aware CLAUDE.md with per-package instructions

When to Use

Use when:

• Multiple packages/apps share code (UI components, utils, types, API clients)
• Build times are slow because everything rebuilds when anything changes
• Migrating from multiple repos to a single repo
• Need to publish packages to npm with coordinated versioning
• Teams work across multiple packages and need unified tooling

Skip when:

• Single-app project with no shared packages
• Team/project boundaries are completely isolated (polyrepo is fine)
• Shared code is minimal and copy-paste overhead is acceptable

Tool Selection

Most modern setups: pnpm workspaces + Turborepo + Changesets

Turborepo

→ See references/monorepo-tooling-reference.md for details

Common Pitfalls

Best Practices

1. Root CLAUDE.md defines the map — document every package, its purpose, and dependency rules
2. Per-package CLAUDE.md defines the rules — what's allowed, what's forbidden, testing commands
3. Always scope commands with --filter — running everything on every change defeats the purpose
4. Remote cache is not optional — without it, monorepo CI is slower than multi-repo CI
5. Changesets over manual versioning — never hand-edit package.json versions in a monorepo
6. Shared configs in root, extended in packages — tsconfig.base.json, .eslintrc.base.js, jest.base.config.js
7. Impact analysis before merging shared package changes — run affected check, communicate blast radius
8. Keep packages/types as pure TypeScript — no runtime code, no dependencies, fast to build and type-check