I figured out how to do this with InjectionTokens (see example below), and if your project was built using the Angular CLI you can use the environment files found in /environments for static application wide settings like an API endpoint, but depending on your project's requirements you will most likely end up using both since environment files are just object literals, while an injectable configuration using InjectionToken's can use the environment variables and since it's a class can have logic applied to configure it based on other factors in the application, such as initial HTTP request data, subdomain, etc.

Injection Tokens Example

/app/app-config.module.ts

import { NgModule, InjectionToken } from '@angular/core';

import { environment } from '../environments/environment';



export let APP_CONFIG = new InjectionToken<AppConfig>('app.config');



export class AppConfig {

  apiEndpoint: string;

}



export const APP_DI_CONFIG: AppConfig = {

  apiEndpoint: environment.apiEndpoint

};



@NgModule({

  providers: [{

    provide: APP_CONFIG,

    useValue: APP_DI_CONFIG

  }]

})

export class AppConfigModule { }

/app/app.module.ts

import { BrowserModule } from '@angular/platform-browser';

import { NgModule } from '@angular/core';



import { AppConfigModule } from './app-config.module';



@NgModule({

  declarations: [

    // ...

  ],

  imports: [

    // ...

    AppConfigModule

  ],

  bootstrap: [AppComponent]

})

export class AppModule { }

Now you can just DI it into any component, service, etc:

/app/core/auth.service.ts

import { Injectable, Inject } from '@angular/core';

import { Http, Response } from '@angular/http';

import { Router } from '@angular/router';

import { Observable } from 'rxjs/Observable';

import 'rxjs/add/operator/map';

import 'rxjs/add/operator/catch';

import 'rxjs/add/observable/throw';



import { APP_CONFIG, AppConfig } from '../app-config.module';

import { AuthHttp } from 'angular2-jwt';



@Injectable()

export class AuthService {



  constructor(

    private http: Http,

    private router: Router,

    private authHttp: AuthHttp,

    @Inject(APP_CONFIG) private config: AppConfig

  ) { }



  /**

   * Logs a user into the application.

   * @param payload

   */

  public login(payload: { username: string, password: string }) {

    return this.http

      .post(`${this.config.apiEndpoint}/login`, payload)

      .map((response: Response) => {

        const token = response.json().token;

        sessionStorage.setItem('token', token); // TODO: can this be done else where? interceptor

        return this.handleResponse(response); // TODO:  unset token shouldn't return the token to login

      })

      .catch(this.handleError);

  }

   

  // ...

}

You can then also type check the config using the exported AppConfig.