Turborepo caching

Turborepo Caching

Production patterns for Turborepo build optimization.

Do not use this skill when

• The task is unrelated to turborepo caching
• You need a different domain or tool outside this scope

Instructions

• Clarify goals, constraints, and required inputs.
• Apply relevant best practices and validate outcomes.
• Provide actionable steps and verification.
• If detailed examples are required, open resources/implementation-playbook.md.

Use this skill when

• Setting up new Turborepo projects
• Configuring build pipelines
• Implementing remote caching
• Optimizing CI/CD performance
• Migrating from other monorepo tools
• Debugging cache misses

Core Concepts

1. Turborepo Architecture

Workspace Root/
├── apps/
│   ├── web/
│   │   └── package.json
│   └── docs/
│       └── package.json
├── packages/
│   ├── ui/
│   │   └── package.json
│   └── config/
│       └── package.json
├── turbo.json
└── package.json

2. Pipeline Concepts

Concept	Description
dependsOn	Tasks that must complete first
cache	Whether to cache outputs
outputs	Files to cache
inputs	Files that affect cache key
persistent	Long-running tasks (dev servers)

Templates

Template 1: turbo.json Configuration

{
  "$schema": "https://turbo.build/schema.json",
  "globalDependencies": [
    ".env",
    ".env.local"
  ],
  "globalEnv": [
    "NODE_ENV",
    "VERCEL_URL"
  ],
  "pipeline": {
    "build": {
      "dependsOn": ["^build"],
      "outputs": [
        "dist/**",
        ".next/**",
        "!.next/cache/**"
      ],
      "env": [
        "API_URL",
        "NEXT_PUBLIC_*"
      ]
    },
    "test": {
      "dependsOn": ["build"],
      "outputs": ["coverage/**"],
      "inputs": [
        "src/**/*.tsx",
        "src/**/*.ts",
        "test/**/*.ts"
      ]
    },
    "lint": {
      "outputs": [],
      "cache": true
    },
    "typecheck": {
      "dependsOn": ["^build"],
      "outputs": []
    },
    "dev": {
      "cache": false,
      "persistent": true
    },
    "clean": {
      "cache": false
    }
  }
}

Template 2: Package-Specific Pipeline

// apps/web/turbo.json
{
  "$schema": "https://turbo.build/schema.json",
  "extends": ["//"],
  "pipeline": {
    "build": {
      "outputs": [".next/**", "!.next/cache/**"],
      "env": [
        "NEXT_PUBLIC_API_URL",
        "NEXT_PUBLIC_ANALYTICS_ID"
      ]
    },
    "test": {
      "outputs": ["coverage/**"],
      "inputs": [
        "src/**",
        "tests/**",
        "jest.config.js"
      ]
    }
  }
}

Template 3: Remote Caching with Vercel

# Login to Vercel
npx turbo login

# Link to Vercel project
npx turbo link

# Run with remote cache
turbo build --remote-only

# CI environment variables
TURBO_TOKEN=your-token
TURBO_TEAM=your-team

# .github/workflows/ci.yml
name: CI

on:
  push:
    branches: [main]
  pull_request:

env:
  TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}
  TURBO_TEAM: ${{ vars.TURBO_TEAM }}

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: 'npm'

      - name: Install dependencies
        run: npm ci

      - name: Build
        run: npx turbo build --filter='...[origin/main]'

      - name: Test
        run: npx turbo test --filter='...[origin/main]'

Template 4: Self-Hosted Remote Cache

// Custom remote cache server (Express)
import express from 'express';
import { createReadStream, createWriteStream } from 'fs';
import { mkdir } from 'fs/promises';
import { join } from 'path';

const app = express();
const CACHE_DIR = './cache';

// Get artifact
app.get('/v8/artifacts/:hash', async (req, res) => {
  const { hash } = req.params;
  const team = req.query.teamId || 'default';
  const filePath = join(CACHE_DIR, team, hash);

  try {
    const stream = createReadStream(filePath);
    stream.pipe(res);
  } catch {
    res.status(404).send('Not found');
  }
});

// Put artifact
app.put('/v8/artifacts/:hash', async (req, res) => {
  const { hash } = req.params;
  const team = req.query.teamId || 'default';
  const dir = join(CACHE_DIR, team);
  const filePath = join(dir, hash);

  await mkdir(dir, { recursive: true });

  const stream = createWriteStream(filePath);
  req.pipe(stream);

  stream.on('finish', () => {
    res.json({ urls: [`${req.protocol}://${req.get('host')}/v8/artifacts/${hash}`] });
  });
});

// Check artifact exists
app.head('/v8/artifacts/:hash', async (req, res) => {
  const { hash } = req.params;
  const team = req.query.teamId || 'default';
  const filePath = join(CACHE_DIR, team, hash);

  try {
    await fs.access(filePath);
    res.status(200).end();
  } catch {
    res.status(404).end();
  }
});

app.listen(3000);

// turbo.json for self-hosted cache
{
  "remoteCache": {
    "signature": false