agent-skills/skills/turborepo/references/configuration/RULE.md

turbo.json Configuration Overview

Configuration reference for Turborepo. Full docs: https://turborepo.dev/docs/reference/configuration

File Location

Root turbo.json lives at repo root, sibling to root package.json:

my-monorepo/
├── turbo.json        # Root configuration
├── package.json
└── packages/
    └── web/
        ├── turbo.json  # Package Configuration (optional)
        └── package.json

Always Prefer Package Tasks Over Root Tasks

Always use package tasks. Only use Root Tasks if you cannot succeed with package tasks.

Package tasks enable parallelization, individual caching, and filtering. Define scripts in each package's package.json:

// packages/web/package.json
{
  "scripts": {
    "build": "next build",
    "lint": "eslint .",
    "test": "vitest",
    "typecheck": "tsc --noEmit"
  }
}

// packages/api/package.json
{
  "scripts": {
    "build": "tsc",
    "lint": "eslint .",
    "test": "vitest",
    "typecheck": "tsc --noEmit"
  }
}

// Root package.json - delegates to turbo
{
  "scripts": {
    "build": "turbo run build",
    "lint": "turbo run lint",
    "test": "turbo run test",
    "typecheck": "turbo run typecheck"
  }
}

When you run turbo run lint, Turborepo finds all packages with a lint script and runs them in parallel.

Root Tasks are a fallback, not the default. Only use them for tasks that truly cannot run per-package (e.g., repo-level CI scripts, workspace-wide config generation).

// AVOID: Task logic in root defeats parallelization
{
  "scripts": {
    "lint": "eslint apps/web && eslint apps/api && eslint packages/ui"
  }
}

Basic Structure

{
  "$schema": "https://turborepo.dev/schema.v2.json",
  "globalEnv": ["CI"],
  "globalDependencies": ["tsconfig.json"],
  "tasks": {
    "build": {
      "dependsOn": ["^build"],
      "outputs": ["dist/**"]
    },
    "dev": {
      "cache": false,
      "persistent": true
    }
  }
}

The $schema key enables IDE autocompletion and validation.

Configuration Sections

Global options - Settings affecting all tasks:

• globalEnv, globalDependencies, globalPassThroughEnv
• cacheDir, daemon, envMode, ui, remoteCache

Task definitions - Per-task settings in tasks object:

• dependsOn, outputs, inputs, env
• cache, persistent, interactive, outputLogs

Package Configurations

Use turbo.json in individual packages to override root settings:

// packages/web/turbo.json
{
  "extends": ["//"],
  "tasks": {
    "build": {
      "outputs": [".next/**", "!.next/cache/**"]
    }
  }
}

The "extends": ["//"] is required - it references the root configuration.

When to use Package Configurations:

• Framework-specific outputs (Next.js, Vite, etc.)
• Package-specific env vars
• Different caching rules for specific packages
• Keeping framework config close to the framework code

Extending from Other Packages

You can extend from config packages instead of just root:

// packages/web/turbo.json
{
  "extends": ["//", "@repo/turbo-config"]
}

Adding to Inherited Arrays with $TURBO_EXTENDS$

By default, array fields in Package Configurations replace root values. Use $TURBO_EXTENDS$ to append instead:

// Root turbo.json
{
  "tasks": {
    "build": {
      "outputs": ["dist/**"]
    }
  }
}

// packages/web/turbo.json
{
  "extends": ["//"],
  "tasks": {
    "build": {
      // Inherits "dist/**" from root, adds ".next/**"
      "outputs": ["$TURBO_EXTENDS$", ".next/**", "!.next/cache/**"]
    }
  }
}

Without $TURBO_EXTENDS$, outputs would only be [".next/**", "!.next/cache/**"].

Works with:

• dependsOn
• env
• inputs
• outputs
• passThroughEnv
• with

Excluding Tasks from Packages

Use extends: false to exclude a task from a package:

// packages/ui/turbo.json
{
  "extends": ["//"],
  "tasks": {
    "e2e": {
      "extends": false  // UI package doesn't have e2e tests
    }
  }
}

turbo.jsonc for Comments

Use turbo.jsonc extension to add comments with IDE support:

// turbo.jsonc
{
  "tasks": {
    "build": {
      // Next.js outputs
      "outputs": [".next/**", "!.next/cache/**"]
    }
  }
}