TypeScript Monorepo Project
In this page:
Core Concept
A full monorepo project applies everything a smaller TypeScript setup uses — project references, a shared-types package, workspace tooling — at the scale of a real multi-package application with a build pipeline tying it together.
Example: Core Concept
// packages/api (references packages/shared)
// packages/web (references packages/shared)
console.log("Project references + shared-types + workspace tooling combined");Basic Setup
A basic setup wires workspace packages (via npm/yarn/pnpm workspaces) with each package's tsconfig.json referencing its dependencies, and a root build script (often Turborepo or Nx) orchestrating builds in dependency order.
Example: Basic Setup
// root: { "workspaces": ["packages/*"] }
// turbo.json orchestrates builds across packages in dependency order
console.log("Turborepo/Nx build packages in the correct dependency order");Typed Example
A typed example: a packages/api package exports typed route handlers, packages/web imports typed API-response shapes from packages/shared, and both build against the same TypeScript version enforced at the workspace root.
Example: Typed Example
// packages/shared/index.ts
export interface ApiUser { id: number; name: string; }
// packages/web imports ApiUser from packages/shared
const user: import("./shared").ApiUser = { id: 1, name: "Ravi" } as any;
console.log("packages/api and packages/web share one TypeScript version");Project Usage
In a real project, build caching (Turborepo/Nx skip rebuilding packages whose inputs haven't changed) is what keeps a large monorepo's CI fast even as the number of packages grows into the dozens.
Example: Project Usage
// turbo run build --filter=...changed
console.log("Build caching skips rebuilding packages with unchanged inputs");Best Practices
Pin a single TypeScript version at the workspace root rather than letting each package specify its own, since mismatched compiler versions across packages in one monorepo are a frequent, hard-to-diagnose source of subtly different type-checking behavior.
Example: Best Practices
// root package.json: { "devDependencies": { "typescript": "5.4.0" } }
// individual packages should NOT pin their own separate typescript version.
console.log("Pin one TypeScript version at the workspace root");Chapter Quiz — Complete all 14 topics to unlock
0/14 topics done
Complete these topics first:
- Todo App with TypeScript
- REST API with Express + TypeScript
- React Dashboard with TypeScript
- CLI Tool with TypeScript
- Library with TypeScript
- Full Stack TypeScript App
- TypeScript Design System
- TypeScript Monorepo Project
- Authentication System
- Real-time App with Socket.io
- GraphQL API with TypeScript
- Microservices with TypeScript
- TypeScript Best Practices Review
- What to Learn Next