Extensions vs Services

const discordService = service({
  name: "discord",
  register: (container) => {
    container.singleton("discordClient", () => new Client({
      token: process.env.DISCORD_TOKEN,
      intents: [GatewayIntentBits.Guilds]
    }));
  },
  boot: async (container) => {
    await container.resolve("discordClient").login();
  },
});

const discord = extension({
  name: "discord",
  services: [discordService], // Uses the service for client
  contexts: [discordContext], // Server/channel state
  actions: [sendMessage, createChannel], // What agent can do
  inputs: [messageListener], // Listen for messages
  outputs: [messageReply], // Send responses
});

// 1. Services handle API connections
const alpacaService = service({
  name: "alpaca",
  register: (container) => {
    container.singleton("alpacaClient", () => new AlpacaApi({
      key: process.env.ALPACA_KEY,
      secret: process.env.ALPACA_SECRET,
    }));
  },
  boot: async (container) => {
    await container.resolve("alpacaClient").authenticate();
  },
});

const marketDataService = service({
  name: "marketData", 
  register: (container) => {
    container.singleton("marketClient", () => new MarketDataClient(process.env.MARKET_KEY));
  },
});

// 2. Extension bundles all trading features
const trading = extension({
  name: "trading",
  services: [alpacaService, marketDataService], // Infrastructure
  contexts: [portfolioContext, watchlistContext], // State management
  actions: [buyStock, sellStock, getQuote], // Capabilities
  inputs: [priceAlerts], // Event listening
  outputs: [orderConfirmation], // Notifications
});

// 3. Agent gets complete trading functionality
const agent = createDreams({
  model: openai("gpt-4o"),
  extensions: [trading], // One line = full trading system
});

Extension Layer (What Agent Can Do)
├── Contexts: portfolio, watchlist state
├── Actions: buy, sell, get quotes  
├── Inputs: listen for price alerts
└── Outputs: send confirmations

Service Layer (How to Connect)
├── alpacaService: trading API client
└── marketDataService: market data client

Execution Flow:
1. Services register and boot (API connections)
2. Extension components merge into agent
3. LLM can use all features automatically
4. Shared infrastructure across all actions