Overview

What Wyrly DI is and when to use it.

Wyrly DI is a small dependency injection toolkit for modern TypeScript applications.

It focuses on explicit wiring instead of runtime type guessing. Your application declares the dependencies it needs, registers concrete providers at the composition root, and resolves use cases from a container or request scope.

When to choose Wyrly

Choose Wyrly when you want:

• TypeScript DI that works with standard decorators
• Typed tokens for interface-based dependencies
• Request scopes for web applications
• A framework-independent core package
• Dependency graph inspection and validation for CI
• A style that works well with DDD and Clean Architecture

When not to choose Wyrly

Wyrly does not try to be a full application framework or a NestJS clone.

It intentionally avoids:

• automatic constructor type metadata
• legacy decorators
• parameter decorators
• global container magic
• auto-scan or glob registration
• framework coupling in the core package

Architecture fit

Wyrly keeps domain and application code independent from framework details.

interface UserRepository {
  findById(id: string): Promise<User | null>;
}

const UserRepositoryToken = token<UserRepository>("UserRepository");

The domain-facing contract stays in your application layer, while the concrete implementation can live in infrastructure code and be wired at the edge of the app.

Next steps

• Install the core package in Installation
• Build your first container in Quickstart
• Learn the mental model in Core model