🤖 Angular Generative AI Demo

Demo

🤔 Why does this matter?

Generative AI is changing the way we interact with technology. As AI chatbots become more commonplace, users expect certain behaviors from our apps, such as realtime text updates. Using LLM APIs, Signals, and some RxJS magic, we can create modern AI-driven user experiences.

🏃 Getting started

[!NOTE]
The Gemini API is free, so long as you're willing to share all of your usage data with Google.

1. Run git clone https://github.com/c-o-l-i-n/ng-generative-ai-demo.git to clone this repo.

2. Visit the Google AI Studio to generate an API key.

3. Create a .env file in the project root with your API key:

   GOOGLE_AI_STUDIO_API_KEY=paste-api-key-here
   

4. Run npm install to install dependencies.

5. Run npm run server to start the backend server (server.ts) on port 3000.

6. In another terminal, run npm start to start the Angular dev server on port 4200.

7. Navigate to http://localhost:4200/

🔑 Key takeaways

• Manage State with Signals: Keep track of the chat state (list of messages and whether the LLM is generating a new message) with Angular Signals.

• Realtime Text Streaming with RxJS Observables: Utilize RxJS to react to realtime updates from the LLM API.

• HTTP Client Configuration: Configure the Angular HTTP client to handle realtime text streams:

  1. Provide the HTTP client "with fetch" in app.config.ts:

  provideHttpClient(withFetch());
  

  2. Tell the HTTP client to observe text events and report progress:

  this.http.post('http://localhost:3000/message', prompt, {
    responseType: 'text',
    observe: 'events',
    reportProgress: true,
  });
  

• Blinking Cursor: Create a blinking cursor effect using the CSS ::after pseudo-element and CSS @keyframes:

  .message {
    &.generating {
      &::after {
        content: '▋';
        animation: fade-cursor ease-in-out 500ms infinite alternate;
      }
    }
  }
  
  @keyframes fade-cursor {
    from {
      opacity: 25%;
    }
    to {
      opacity: 100%;
    }
  }
  

🔭 Files to explore

• message.service.ts
• app.config.ts
• server.ts