Wireit

Wireit is a zero-dependency inversion of control (IoC) container for TypeScript. Register dependencies with typed tokens, resolve them synchronously or asynchronously, and scope lifetimes to containers or request cycles with full type inference.

Installation

pnpm

pnpm add @vielzeug/wireit

npm

npm install @vielzeug/wireit

yarn

yarn add @vielzeug/wireit

Quick Start

import { createContainer, createToken } from '@vielzeug/wireit';

const DbToken = createToken<Database>('Database');
const ServiceToken = createToken<UserService>('UserService');

const container = createContainer();

container
  .factory(DbToken, () => new Database(process.env.DB_URL!))
  .bind(ServiceToken, UserService, { deps: [DbToken] });

const service = container.get(ServiceToken);

Why Wireit?

Manual dependency wiring gets hard to scale: constructors balloon, test setup repeats, and switching implementations requires touching many call sites.

// Before — manual wiring
const config = loadConfig();
const db = new Database(config.dbUrl);
const repo = new UserRepository(db);
const serviceBefore = new UserService(repo);

// After — Wireit
const container = createContainer();
container
  .value(ConfigToken, loadConfig())
  .factory(DbToken, (config) => new Database(config.dbUrl), { deps: [ConfigToken] })
  .bind(RepoToken, UserRepository, { deps: [DbToken] })
  .bind(SvcToken, UserService, { deps: [RepoToken] });

const serviceAfter = container.get(SvcToken);

Feature	Wireit	InversifyJS	tsyringe
Bundle size	1.7 KB	~11 kB	~6 kB
Decorators required	❌	✅	✅
reflect-metadata	❌	✅	✅
Typed tokens	✅ Explicit createToken<T>()	Partial	Partial
Async providers	✅	✅	✅
Child containers	✅	✅	✅
Snapshot and restore	✅	❌	❌
Built-in mocking	✅ container.mock()	❌	❌
Zero dependencies	✅	❌	❌

Use Wireit when you want predictable, type-safe DI without decorators, metadata, or heavyweight framework conventions.

Consider alternatives when you already rely on decorator-based DI and want to stay aligned with that ecosystem.

Features

• Typed tokens — createToken<T>(description) gives every dependency a compile-time type and a human-readable name
• Three registration styles — register(), factory() shorthand, bind() shorthand, and value() for constants
• Lifetimes — singleton (default), transient, and scoped per-child-container
• Async providers — factories may return Promise<T>; resolve via getAsync() and getAllAsync()
• Dispose hooks — per-provider dispose(instance) called on container.dispose(); [Symbol.asyncDispose] for await using
• Child containers — createChild() inherits registrations; scoped instances are isolated per child
• Scoped execution — runInScope(fn) creates and auto-disposes a child container
• Aliases — alias(token, source) maps interfaces to implementations, resolved through the full parent chain
• Batch resolution — getAll and getAllAsync return typed tuples
• Optional resolution — getOptional and getOptionalAsync return undefined when missing
• Test utilities — createTestContainer() and container.mock() for isolated unit tests
• Snapshot/Restore — snapshot() / restore() for fine-grained test state control
• Debug — debug() walks the full hierarchy and lists all tokens and aliases
• Zero dependencies — 1.7 KB gzipped

Compatibility

Environment	Support
Browser	✅
Node.js	✅
SSR	✅
Deno	✅

See Also

• Permit
• Fetchit
• Workit