@nyalajs/core

The foundation of Nyala.js — dependency injection, module system, decorators, and application lifecycle. Every other @nyalajs/* package builds on this one; it has no dependencies of its own beyond reflect-metadata.

Quick start

import "reflect-metadata";
import { Module, Controller, Get, Injectable, NyalaFactory } from "@nyalajs/core";

@Injectable()
class GreeterService {
  greet(name: string) {
    return `Hello, ${name}`;
  }
}

@Controller("/hello")
class HelloController {
  constructor(private greeter: GreeterService) {}

  @Get("/:name")
  hello(@Param("name") name: string) {
    return { message: this.greeter.greet(name) };
  }
}

@Module({ providers: [GreeterService], controllers: [HelloController] })
class AppModule {}

const app = await NyalaFactory.create(AppModule);
// attach an HTTP adapter (see @nyalajs/http) and app.listen(3000)

What's in this package

• Modules — @Module({ imports, providers, controllers, exports }). The module loader builds a dependency graph, detects circular imports, and validates that anything a module exports is actually provided by it.
• Dependency injection — constructor injection via @Injectable()/@Inject(token); singleton, request, and transient scopes; a request-scoped child container is created per HTTP request.
• Controllers & routing metadata — @Controller(), @Get()/@Post()/@Put()/@Delete()/@Patch(), @Body()/@Param()/@Query()/@Req()/@Res()/@Headers()/@Cookie() and more — the decorators; @nyalajs/http's FastifyAdapter does the actual binding to a real server.
• Cross-cutting concerns — @UseGuards(), @UseInterceptors(), @Catch()/@UseFilters() for exception filters.
• Lifecycle hooks — OnModuleInit, OnApplicationBootstrap, OnApplicationShutdown.
• NyalaApplication/NyalaFactory — application bootstrap, plugin registration (app.plugin(...)), global middleware (app.use(...)).
• Context — TenantContext/LogContext, AsyncLocalStorage-backed request-scoped state readable from anywhere in the call chain, including code with no access to the request object.

Runtime, not just types

This package is a real dependency-injection runtime, not a types-only decorator library — resolving a provider actually walks a dependency graph, instantiates classes with their constructor dependencies injected, and caches according to scope. See @nyalajs/testing's TestingModule for exercising it in tests without spinning up a real HTTP server.

Documentation

Full docs: github.com/nyalajs/nyalajs.