gmail-agent.ts

import {
  experimental_createMCPClient,
  generateText,
  stepCountIs,
  type CoreMessage,
} from "ai";
import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
import { createOpenRouter } from "@openrouter/ai-sdk-provider";
import { Composio } from "@composio/core";
import * as readline from "readline";

const openrouter = createOpenRouter({
  apiKey: process.env.OPENROUTER_API_KEY,
});

const composio = new Composio({
  apiKey: process.env.COMPOSIO_APIKEY!,
});

const session = await composio.experimental.toolRouter.createSession(
  "rahul@composio.dev",
  {
    toolkits: ["gmail"],
  }
);

console.log("session id:", session.sessionId);

const httpTransport = new StreamableHTTPClientTransport(new URL(session.url));
const httpClient = await experimental_createMCPClient({
  transport: httpTransport,
});

const tools = await httpClient.tools();

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
});

const messages: CoreMessage[] = [];

console.log("\ngmail agent ready. type your messages (ctrl+c to exit)\n");

const chat = async (userMessage: string) => {
  messages.push({
    role: "user",
    content: userMessage,
  });

  const result = await generateText({
    model: openrouter("anthropic/claude-4.5-sonnet"),
    system: "you are a gmail agent for the user",
    messages: messages,
    tools: tools,
    stopWhen: stepCountIs(25),
  });

  messages.push({
    role: "assistant",
    content: result.text,
  });

  console.log("\nassistant:", result.text, "\n");
};

const prompt = () => {
  rl.question("you: ", async (input) => {
    if (!input.trim()) {
      prompt();
      return;
    }

    await chat(input);
    prompt();
  });
};

prompt();