A simple TypeScript library for dependency injection
npm install @needle-di/core> A lightweight, type-safe Dependency Injection (DI) library for JavaScript and TypeScript projects.





Needle DI is a lightweight, TypeScript-first library for dependency injection (DI). It is designed to be both easy to use and highly efficient.
- Stand-alone: No additional dependencies required
- Intended for both JavaScript-only and TypeScript projects
- Supports tree-shakeable injection tokens: optimize your builds for production.
- Inspired by Angular and InversifyJS, familiar to developers coming from these frameworks.
- Uses native ECMAScript decorators (currently stage 3)
- No need for experimentalDecorators and emitDecoratorMetadata
- No reflection libraries needed, like reflect-metadata or other reflection mechanisms.
Here’s a simple example using constructor injection to inject one service into another.
``typescript
import { injectable, inject } from "@needle-di/core";
@injectable()
class FooService {}
@injectable()
class BarService {
constructor(private fooService = inject(FooService)) {}
// ^? Type will be inferred as FooService`
}
The @injectable decorator eliminates the need to manually register services. To construct the BarService, create acontainer.get()
dependency injection container, and use the method:
`typescript
import { Container } from "@needle-di/core";
const container = new Container();
const barService = container.get(BarService);
// ^? Type will be inferred as BarService`
Check out the docs to learn more!
``
npm install --save @needle-di/core
Needle DI also works with Deno and is published to JSR as well:
`bash``
deno add jsr:@needle-di/core
Check out our docs on https://needle-di.io.
License under the MIT License (MIT)
Copyright (c) 2024 - 2025 Dirk Luijk
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