create-t3-turbo

Orchestrates build tasks across multiple applications and packages using Turborepo's task graph engine with incremental caching. Analyzes package dependencies declared in turbo.json, caches build artifacts based on file hashing, and parallelizes independent tasks across the workspace. Enables developers to run 'turbo build' once and have only changed packages rebuild, dramatically reducing full-stack build times in multi-application environments.

Implements end-to-end type safety from database schema through API to client using tRPC's router-based RPC framework combined with Zod validators in the @acme/validators package. Both Next.js and Expo applications import the same tRPC router type definitions, enabling TypeScript to enforce request/response contracts at compile time. Validators are defined once in a shared package and reused across server and client, eliminating schema duplication and runtime type mismatches.

Configures GitHub Actions workflows (.github/workflows/ci.yml) to run tests, linting, and type checking across the entire monorepo using Turborepo's task orchestration. The pipeline runs only on changed packages (via Turborepo's affected task detection), reducing CI time. Separate workflows handle Next.js deployment to Vercel and Expo deployment to EAS, with automatic environment variable injection and build caching. The template demonstrates how to parallelize independent tasks and cache dependencies across workflow runs.

Centralizes code quality configurations in the tooling/ directory: ESLint rules, Prettier formatting, and TypeScript compiler options are defined once and shared across all packages and applications via extends mechanism. This ensures consistent code style, linting rules, and type checking across the monorepo without duplication. The template includes pre-configured rules for React, Next.js, React Native, and TypeScript best practices, with a single tsconfig.json at the root that all packages extend.

Provides a CLI tool (create-t3-turbo) that scaffolds a new monorepo with pre-configured packages, applications, and tooling. The CLI prompts for project name, replaces the @acme namespace with the user's organization name, installs dependencies, and initializes git. This eliminates manual setup of workspace configuration, package.json files, and build tooling, enabling developers to start building full-stack applications immediately with best practices baked in.

Centralizes ESLint and Prettier configuration in tooling/eslint and tooling/prettier directories, with shared rules and formatting settings applied to all packages and apps. Each package extends the base configuration, ensuring consistent code style and linting rules across the monorepo. Prettier is integrated with ESLint to auto-fix formatting issues during development and CI/CD.

Centralizes database schema definition in the @acme/db package using Drizzle ORM's TypeScript-first schema builder, generating both SQL migrations and TypeScript types from a single source of truth. The schema is defined declaratively in TypeScript (not SQL), and Drizzle generates migration files that can be version-controlled and applied consistently across development, staging, and production environments. Both Next.js and Expo applications import the same schema types, ensuring database queries are type-checked at compile time.

Provides a shared @acme/ui package containing React components styled with Tailwind CSS that render natively on both web (Next.js) and mobile (Expo/React Native) platforms. Components use platform-agnostic React patterns (hooks, composition) and Tailwind's utility classes, which are compiled to CSS for web and converted to React Native styles for mobile via Tailwind's React Native plugin. This eliminates component duplication and ensures visual consistency across platforms.

Uses pnpm workspaces and the workspace:* protocol to link local packages during development without publishing to npm. When a package declares a dependency as 'workspace:*', pnpm creates a symlink to the local package, enabling instant feedback on changes across @acme/api, @acme/db, @acme/ui, and @acme/auth. During publishing, pnpm automatically converts workspace:* references to concrete version numbers, ensuring published packages have explicit version constraints.

Implements architectural guardrails by restricting how packages can depend on each other: applications (@acme/nextjs, @acme/expo) depend only on @acme/api and @acme/ui, never directly on @acme/db or @acme/auth. This layering is enforced through package.json configuration and documented in README, preventing applications from bypassing the API layer and accessing the database directly. The pattern ensures all data access flows through tRPC procedures, maintaining consistent validation, authentication, and business logic.

Integrates tRPC into Next.js 15's App Router using React Server Components and client-side hooks. Server components can directly call tRPC procedures without HTTP overhead, while client components use tRPC's useQuery and useMutation hooks for data fetching and mutations. The template provides pre-configured tRPC client setup that handles authentication context (via NextAuth.js or similar) and request batching, enabling efficient data loading patterns across server and client boundaries.

Configures Expo Router (file-based routing for React Native) to work with tRPC client hooks for API communication. Mobile screens import tRPC hooks (useQuery, useMutation) to fetch data from the same API as the web app, with automatic request batching and caching. The template includes environment configuration to point the Expo app to the correct API endpoint (localhost for development, production URL for EAS builds), and handles authentication tokens via secure storage.

Implements authentication logic in the @acme/auth package, which is imported by both Next.js and Expo applications. The package abstracts authentication provider details (NextAuth.js for web, Expo SecureStore for mobile) behind a common interface, enabling both platforms to share session validation, token refresh, and user context logic. The template demonstrates how to pass authentication context through tRPC middleware, ensuring all API calls include valid credentials and are properly authorized.

Provides environment configuration management for development, staging, and production across web and mobile. The template uses .env files for local development and environment variables for CI/CD pipelines. For Next.js, environment variables are injected at build time via next.config.js. For Expo, EAS Build reads environment variables and injects them into the app during compilation. This enables the same codebase to deploy to different environments with different API endpoints, database connections, and feature flags.