Turborepo

Turborepo

Turborepo is a high-performance build system for JavaScript/TypeScript monorepos. It provides intelligent caching, parallel execution, and incremental builds.

Core Concepts

Monorepo Structure

my-turborepo/
├── apps/
│   ├── web/              # Next.js app
│   │   ├── package.json
│   │   └── next.config.js
│   └── docs/             # Documentation site
│       └── package.json
├── packages/
│   ├── ui/               # Shared component library
│   │   ├── package.json
│   │   └── src/
│   ├── config/           # Shared configs (ESLint, TS, etc.)
│   │   └── package.json
│   └── utils/            # Shared utilities
│       └── package.json
├── turbo.json            # Turborepo configuration
├── package.json          # Root package.json
└── pnpm-workspace.yaml   # Workspace definition

turbo.json Configuration

{
  "$schema": "https://turborepo.com/schema.json",
  "ui": "stream",
  "envMode": "strict",
  "tasks": {
    "build": {
      "dependsOn": ["^build"],
      "inputs": ["$TURBO_DEFAULT$", ".env*"],
      "outputs": [".next/**", "!.next/cache/**", "dist/**"],
      "env": ["NODE_ENV", "DATABASE_URL", "NEXT_PUBLIC_*"]
    },
    "dev": {
      "cache": false,
      "persistent": true,
      "interactive": true
    },
    "lint": {
      "dependsOn": ["^build"],
      "outputs": []
    },
    "test": {
      "dependsOn": ["build"],
      "inputs": ["src/**", "test/**"],
      "outputs": ["coverage/**"]
    },
    "typecheck": {
      "dependsOn": ["^build"],
      "outputs": []
    }
  }
}

Workspace Package.json

{
  "name": "my-turborepo",
  "private": true,
  "scripts": {
    "build": "turbo run build",
    "dev": "turbo run dev",
    "lint": "turbo run lint",
    "test": "turbo run test",
    "typecheck": "turbo run typecheck",
    "clean": "turbo run clean && rm -rf node_modules"
  },
  "devDependencies": {
    "turbo": "^2.7.2"
  },
  "packageManager": "pnpm@10.26.0"
}

pnpm-workspace.yaml

packages:
  - 'apps/*'
  - 'packages/*'

Task Configuration

Dependency Types

{
  "tasks": {
    // Topological dependency (dependencies first)
    "build": {
      "dependsOn": ["^build"] // Run build in all dependencies first
    },

    // Same-package dependency
    "test": {
      "dependsOn": ["build"] // Run build in same package first
    },

    // Cross-package specific dependency
    "deploy": {
      "dependsOn": ["build", "test", "^build"]
    },

    // Arbitrary package#task dependency
    "e2e": {
      "dependsOn": ["web#build", "api#build"] // Specific packages
    }
  }
}

Input/Output Configuration

{
  "tasks": {
    "build": {
      // Files that affect cache
      "inputs": [
        "$TURBO_DEFAULT$", // Default: all non-gitignored files
        "!README.md", // Exclude README changes
        ".env.production", // Include specific env file
        "$TURBO_ROOT$/tsconfig.json" // Reference files from repo root
      ],
      // Files produced by task
      "outputs": [
        "dist/**",
        ".next/**",
        "!.next/cache/**" // Exclude .next/cache
      ]
    }
  }
}

Note: The following files are always considered inputs and cannot be ignored:

• package.json
• turbo.json
• Package manager lockfiles (automatically included in global hash)

Environment Variables

{
  "globalEnv": ["CI", "VERCEL"],
  "globalPassThroughEnv": ["AWS_ACCESS_KEY"],
  "tasks": {
    "build": {
      "env": [
        "DATABASE_URL",
        "NEXT_PUBLIC_*", // Wildcard: all vars starting with NEXT_PUBLIC_
        "!GITHUB_*" // Negation: exclude GITHUB_ vars from strict mode
      ],
      "passThroughEnv": ["AWS_SECRET_KEY"] // Available but not in cache hash
    }
  }
}

Caching

Local Caching

# Cache stored in node_modules/.cache/turbo
turbo run build

# Force cache miss
turbo run build --force

Remote Caching

# Login to Vercel Remote Cache
npx turbo login

# Link project
npx turbo link

# Or use custom cache server
TURBO_API="https://cache.example.com"
TURBO_TOKEN="your-token"
TURBO_TEAM="your-team"

Cache Configuration

{
  "tasks": {
    "build": {
      "cache": true, // Enable caching (default)
      "outputLogs": "new-only" // Show logs only on cache miss
    },
    "dev": {
      "cache": false, // Disable caching for dev
      "persistent": true, // Long-running task
      "interactive": true // Accepts keyboard input (stdin)
    },
    "db:studio": {
      "cache": false,
      "persistent": true,
      "interruptible": true // Can be restarted when dependencies change
    }
  }
}

Development Mode

turbo watch

Re-run tasks automatically when files change:

# Watch all tasks
turbo watch build lint typecheck

# Watch specific packages
turbo watch build --filter=web

# Write cache in watch mode (experimental)
turbo watch build --experimental-write-cache

Watch mode is dependency-aware - when a package changes, all dependent packages re-run their tasks. Persistent tasks (dev servers) are automatically handled.

Docker Optimization

turbo prune

Generate a partial monorepo for efficient Docker builds:

# Basic prune
turbo prune web

# Docker-optimized output (recommended)
turbo prune web --docker

The --docker flag creates:

• out/json/ - package.json files only (for dependency layer)
• out/full/ - Complete pruned workspace (for build layer)

Dockerfile Pattern

FROM node:22-alpine AS builder
WORKDIR /app

# Install turbo globally
RUN npm install -g turbo

# Copy all files and prune
COPY . .
RUN turbo prune web --docker

# Install dependencies (cached layer)
FROM node:22-alpine AS installer
WORKDIR /app
COPY --from=builder /app/out/json/ .
RUN npm install

# Build the app
COPY --from=builder /app/out/full/ .
RUN npx turbo run build --filter=web

# Production image
FROM node:22-alpine AS runner
WORKDIR /app
COPY --from=installer /app/apps/web/.next/standalone ./
COPY --from=installer /app/apps/web/.next/static ./apps/web/.next/static
COPY --from=installer /app/apps/web/public ./apps/web/public

CMD ["node", "apps/web/server.js"]

Filtering

Package Filters

# Run build only in web app
turbo run build --filter=web

# Run in web and its dependencies
turbo run build --filter=web...

# Run in packages that depend on ui
turbo run build --filter=...^ui

# Target specific task in specific package
turbo run web#lint

Source Control Filters

# Packages changed since main branch
turbo run build --filter=[main...my-feature]

# Packages changed since previous commit
turbo run build --filter=[HEAD^1]

# Packages changed between specific commits
turbo run build --filter=[a1b2c3d...e4f5g6h]

# Build all packages depending on changes in branch
turbo run build --filter=...[origin/my-feature]

# Combine package and source control filters
turbo run build --filter=@acme/ui...[HEAD^1]
turbo run test --filter=@acme/*{./packages/*}[HEAD^1]

Affected Flag (CI Optimized)

# Run only on packages with code changes (auto-detects CI environment)
turbo run build --affected

# Override comparison branches via environment
TURBO_SCM_BASE=main TURBO_SCM_HEAD=HEAD turbo run build --affected

Workspace Filters

# All apps
turbo run build --filter="./apps/*"

# All packages
turbo run build --filter="./packages/*"

# Exclude specific package
turbo run build --filter=./apps/* --filter=!./apps/admin

# Multiple specific packages
turbo run build --filter=docs --filter=web

Package Configuration

Internal Package (packages/ui/package.json)

{
  "name": "@repo/ui",
  "version": "0.0.0",
  "private": true,
  "exports": {
    ".": "./src/index.tsx",
    "./button": "./src/button.tsx",
    "./card": "./src/card.tsx"
  },
  "scripts": {
    "build": "tsup",
    "lint": "eslint src/",
    "typecheck": "tsc --noEmit"
  },
  "devDependencies": {
    "@repo/config": "workspace:*",
    "typescript": "^5.0.0"
  }
}

App Package (apps/web/package.json)

{
  "name": "web",
  "version": "0.0.0",
  "private": true,
  "scripts": {
    "build": "next build",
    "dev": "next dev",
    "lint": "next lint",
    "start": "next start"
  },
  "dependencies": {
    "@repo/ui": "workspace:*",
    "@repo/utils": "workspace:*",
    "next": "^16.1.1",
    "react": "^19.0.0"
  }
}

CI/CD Integration

GitHub Actions

name: CI

on:
  push:
    branches: [main]
  pull_request:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0 # Full history for --affected flag

      - uses: pnpm/action-setup@v4
        with:
          version: 10

      - uses: actions/setup-node@v4
        with:
          node-version: 22
          cache: 'pnpm'

      - run: pnpm install --frozen-lockfile

      # Option 1: Run all tasks with remote caching
      - run: pnpm turbo run build lint test
        env:
          TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}
          TURBO_TEAM: ${{ vars.TURBO_TEAM }}

      # Option 2: Run only affected packages (optimized for large repos)
      - run: pnpm turbo run build lint test --affected
        env:
          TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}
          TURBO_TEAM: ${{ vars.TURBO_TEAM }}

Best Practices

1. Keep packages focused - Single responsibility
2. Use workspace protocol - workspace:* for internal deps
3. Share configs - Put ESLint, TS config in packages/config
4. Cache aggressively - Remote caching for CI
5. Filter in CI - Only build what changed

References

• references/configuration.md - Full config reference
• references/filters.md - Filter patterns