How to integrate Google Calendar MCP with OpenAI Agents SDK

This guide walks you through connecting Google Calendar to the OpenAI Agents SDK using the Composio tool router. By the end, you'll have a working Google Calendar agent that can create a meeting with the marketing team, list all events scheduled for next week, delete tomorrow’s canceled event from your calendar through natural language commands. This guide will help you understand how to give your OpenAI Agents SDK agent real control over a Google Calendar account through Composio's Google Calendar MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Google Calendar logoGoogle Calendar
Oauth2

Google Calendar is a time management service for scheduling meetings, events, and reminders. It streamlines personal and team organization with integrated notifications and sharing options.

44 Tools7 Triggers

Introduction

This guide walks you through connecting Google Calendar to the OpenAI Agents SDK using the Composio tool router. By the end, you'll have a working Google Calendar agent that can create a meeting with the marketing team, list all events scheduled for next week, delete tomorrow’s canceled event from your calendar through natural language commands.

This guide will help you understand how to give your OpenAI Agents SDK agent real control over a Google Calendar account through Composio's Google Calendar MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

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TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Install the necessary dependencies
  • Initialize Composio and create a Tool Router session for Google Calendar
  • Configure an AI agent that can use Google Calendar as a tool
  • Run a live chat session where you can ask the agent to perform Google Calendar operations

What is OpenAI Agents SDK?

The OpenAI Agents SDK is a lightweight framework for building AI agents that can use tools and maintain conversation state. It provides a simple interface for creating agents with hosted MCP tool support.

Key features include:

  • Hosted MCP Tools: Connect to external services through hosted MCP endpoints
  • SQLite Sessions: Persist conversation history across interactions
  • Simple API: Clean interface with Agent, Runner, and tool configuration
  • Streaming Support: Real-time response streaming for interactive applications

What is the Google Calendar MCP server, and what's possible with it?

The Google Calendar MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Google Calendar account. It provides structured and secure access to your calendars and events, so your agent can schedule meetings, create or modify events, list upcoming appointments, and manage calendars—all on your behalf.

  • Automated event creation and scheduling: Easily instruct your agent to add new events, meetings, or reminders with specific times, attendees, and details.
  • Event listing and agenda overview: Have your agent list all upcoming, past, or filtered events on any of your calendars to keep you on top of your schedule.
  • Calendar management and customization: Direct your agent to create new calendars, update calendar details, or even insert calendars into your list for better organization.
  • Event updating and deletion: Let your agent modify existing events or remove events that are no longer needed, keeping your calendar up to date.
  • Complete calendar clearing: Ask your agent to clear all events from a primary calendar or delete secondary calendars entirely when you need a fresh start.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

  1. Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
  2. Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
  3. Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS
1

Prerequisites

Before starting, make sure you have:
  • Composio API Key and OpenAI API Key
  • Primary know-how of OpenAI Agents SDK
  • A live Google Calendar project
  • Some knowledge of Python or Typescript
2

Getting API Keys for OpenAI and Composio

OpenAI API Key
  • Go to the OpenAI dashboard and create an API key. You'll need credits to use the models, or you can connect to another model provider.
  • Keep the API key safe.
Composio API Key
3

Install dependencies

npm install @composio/openai-agents @openai/agents dotenv

Install the Composio SDK and the OpenAI Agents SDK.

4

Set up environment variables

bash
OPENAI_API_KEY=sk-...your-api-key
COMPOSIO_API_KEY=your-api-key
USER_ID=composio_user@gmail.com

Create a .env file and add your OpenAI and Composio API keys.

5

Import dependencies

import 'dotenv/config';
import { Composio } from '@composio/core';
import { OpenAIAgentsProvider } from '@composio/openai-agents';
import { Agent, hostedMcpTool, run, OpenAIConversationsSession } from '@openai/agents';
import * as readline from 'readline';
What's happening:
  • You're importing all necessary libraries.
  • The Composio and OpenAIAgentsProvider classes are imported to connect your OpenAI agent to Composio tools like Google Calendar.
6

Set up the Composio instance

dotenv.config();

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.USER_ID;

if (!composioApiKey) {
  throw new Error('COMPOSIO_API_KEY is not set. Create a .env file with COMPOSIO_API_KEY=your_key');
}
if (!userId) {
  throw new Error('USER_ID is not set');
}

// Initialize Composio
const composio = new Composio({
  apiKey: composioApiKey,
  provider: new OpenAIAgentsProvider(),
});
What's happening:
  • dotenv.config() loads your .env file so COMPOSIO_API_KEY and USER_ID are available as environment variables.
  • Creating a Composio instance using the API Key and OpenAIAgentsProvider class.
7

Create a Tool Router session

// Create Tool Router session for Google Calendar
const session = await composio.create(userId as string, {
  toolkits: ['googlecalendar'],
});
const mcpUrl = session.mcp.url;

What is happening:

  • You give the Tool Router the user id and the toolkits you want available. Here, it is only googlecalendar.
  • The router checks the user's Google Calendar connection and prepares the MCP endpoint.
  • The returned session.mcp.url is the MCP URL that your agent will use to access Google Calendar.
  • This approach keeps things lightweight and lets the agent request Google Calendar tools only when needed during the conversation.
8

Configure the agent

// Configure agent with MCP tool
const agent = new Agent({
  name: 'Assistant',
  model: 'gpt-5',
  instructions:
    'You are a helpful assistant that can access Google Calendar. Help users perform Google Calendar operations through natural language.',
  tools: [
    hostedMcpTool({
      serverLabel: 'tool_router',
      serverUrl: mcpUrl,
      headers: { 'x-api-key': composioApiKey },
      requireApproval: 'never',
    }),
  ],
});
What's happening:
  • We're creating an Agent instance with a name, model (gpt-5), and clear instructions about its purpose.
  • The agent's instructions tell it that it can access Google Calendar and help with queries, inserts, updates, authentication, and fetching database information.
  • The tools array includes a hostedMcpTool that connects to the MCP server URL we created earlier.
  • The headers object includes the Composio API key for secure authentication with the MCP server.
  • requireApproval: 'never' means the agent can execute Google Calendar operations without asking for permission each time, making interactions smoother.
9

Start chat loop and handle conversation

// Keep conversation state across turns
const conversationSession = new OpenAIConversationsSession();

// Simple CLI
const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
  prompt: 'You: ',
});

console.log('\nComposio Tool Router session created.');
console.log('\nChat started. Type your requests below.');
console.log("Commands: 'exit', 'quit', or 'q' to end\n");

try {
  const first = await run(agent, 'What can you help me with?', { session: conversationSession });
  console.log(`Assistant: ${first.finalOutput}\n`);
} catch (e) {
  console.error('Error:', e instanceof Error ? e.message : e, '\n');
}

rl.prompt();

rl.on('line', async (userInput) => {
  const text = userInput.trim();

  if (['exit', 'quit', 'q'].includes(text.toLowerCase())) {
    console.log('Goodbye!');
    rl.close();
    process.exit(0);
  }

  if (!text) {
    rl.prompt();
    return;
  }

  try {
    const result = await run(agent, text, { session: conversationSession });
    console.log(`\nAssistant: ${result.finalOutput}\n`);
  } catch (e) {
    console.error('Error:', e instanceof Error ? e.message : e, '\n');
  }

  rl.prompt();
});

rl.on('close', () => {
  console.log('\n👋 Session ended.');
  process.exit(0);
});
What's happening:
  • The program prints a session URL that you visit to authorize Google Calendar.
  • After authorization, the chat begins.
  • Each message you type is processed by the agent using run().
  • The responses are printed to the console.
  • Typing exit, quit, or q cleanly ends the chat.

Complete Code

Here's the complete code to get you started with Google Calendar and OpenAI Agents SDK:

import 'dotenv/config';
import { Composio } from '@composio/core';
import { OpenAIAgentsProvider } from '@composio/openai-agents';
import { Agent, hostedMcpTool, run, OpenAIConversationsSession } from '@openai/agents';
import * as readline from 'readline';

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.USER_ID;

if (!composioApiKey) {
  throw new Error('COMPOSIO_API_KEY is not set. Create a .env file with COMPOSIO_API_KEY=your_key');
}
if (!userId) {
  throw new Error('USER_ID is not set');
}

// Initialize Composio
const composio = new Composio({
  apiKey: composioApiKey,
  provider: new OpenAIAgentsProvider(),
});

async function main() {
  // Create Tool Router session
  const session = await composio.create(userId as string, {
    toolkits: ['googlecalendar'],
  });
  const mcpUrl = session.mcp.url;

  // Configure agent with MCP tool
  const agent = new Agent({
    name: 'Assistant',
    model: 'gpt-5',
    instructions:
      'You are a helpful assistant that can access Google Calendar. Help users perform Google Calendar operations through natural language.',
    tools: [
      hostedMcpTool({
        serverLabel: 'tool_router',
        serverUrl: mcpUrl,
        headers: { 'x-api-key': composioApiKey },
        requireApproval: 'never',
      }),
    ],
  });

  // Keep conversation state across turns
  const conversationSession = new OpenAIConversationsSession();

  // Simple CLI
  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: ',
  });

  console.log('\nComposio Tool Router session created.');
  console.log('\nChat started. Type your requests below.');
  console.log("Commands: 'exit', 'quit', or 'q' to end\n");

  try {
    const first = await run(agent, 'What can you help me with?', { session: conversationSession });
    console.log(`Assistant: ${first.finalOutput}\n`);
  } catch (e) {
    console.error('Error:', e instanceof Error ? e.message : e, '\n');
  }

  rl.prompt();

  rl.on('line', async (userInput) => {
    const text = userInput.trim();

    if (['exit', 'quit', 'q'].includes(text.toLowerCase())) {
      console.log('Goodbye!');
      rl.close();
      process.exit(0);
    }

    if (!text) {
      rl.prompt();
      return;
    }

    try {
      const result = await run(agent, text, { session: conversationSession });
      console.log(`\nAssistant: ${result.finalOutput}\n`);
    } catch (e) {
      console.error('Error:', e instanceof Error ? e.message : e, '\n');
    }

    rl.prompt();
  });

  rl.on('close', () => {
    console.log('\nSession ended.');
    process.exit(0);
  });
}

main().catch((err) => {
  console.error('Fatal error:', err);
  process.exit(1);
});

Conclusion

This was a starter code for integrating Google Calendar MCP with OpenAI Agents SDK to build a functional AI agent that can interact with Google Calendar.

Key features:

  • Hosted MCP tool integration through Composio's Tool Router
  • SQLite session persistence for conversation history
  • Simple async chat loop for interactive testing
You can extend this by adding more toolkits, implementing custom business logic, or building a web interface around the agent.
TOOLS & TRIGGERS

Supported Tools and Triggers

Every Google Calendar action and event your agent gets out of the box.

Delete ACL Rule

Deletes an access control rule from a Google Calendar.

Get ACL Rule

Retrieves a specific access control rule for a calendar.

Create ACL Rule

Creates an access control rule for a calendar.

List ACL Rules

Retrieves the list of access control rules (ACLs) for a specified calendar, providing the necessary 'rule_id' values required for updating specific ACL rules.

Patch ACL Rule

Updates an existing access control rule for a calendar using patch semantics (partial update).

Update ACL Rule

Updates an access control rule for the specified calendar.

Watch ACL Changes

Tool to watch for changes to ACL resources.

Batch Events

Execute up to 1000 event mutations (create/patch/delete) in one Google Calendar HTTP batch request with per-item status/results.

Remove Calendar from List

Tool to remove a calendar from the user's calendar list.

Get Single Calendar by ID

Retrieves metadata for a SINGLE specific calendar from the user's calendar list by its calendar ID.

Insert Calendar into List

Inserts an existing calendar into the user's calendar list, making it visible in the UI.

Patch Calendar List Entry

Updates an existing calendar on the user's calendar list using patch semantics.

Update Calendar List Entry

Updates a calendar list entry's display/subscription settings (color, visibility, reminders, selection) for the authenticated user — does not modify the underlying calendar resource (title, timezone, etc.

Watch Calendar List

Watch for changes to CalendarList resources using push notifications.

Delete Calendar

Deletes a secondary calendar that you own or have delete permissions on.

Update Calendar

Full PUT-style update that overwrites all calendar metadata fields; unspecified optional fields are cleared.

Stop Channel

Tool to stop watching resources through a notification channel.

Clear Calendar

Clears a primary calendar by deleting all events from it.

Get Color Definitions

Returns the color definitions for calendars and events.

Create Event

Create a Google Calendar event using start_datetime plus duration fields.

Delete event

Deletes a specified event by `event_id` from a Google Calendar (`calendar_id`); idempotent — a 404 for an already-deleted event is a no-op.

Create a calendar

Creates a new, empty Google Calendar with the specified title (summary).

Get Event

Retrieves a SINGLE event by its unique event_id (REQUIRED).

Import Event

Tool to import an event as a private copy to a calendar.

Get Event Instances

Returns instances of the specified recurring event.

List Events

Returns events on the specified calendar.

List Events from All Calendars

Return a unified event list across all calendars in the user's calendar list for a given time range.

Move Event

Moves an event to another calendar, i.

Watch Events

Watch for changes to Events resources.

Find event

Finds events in a specified Google Calendar using text query, time ranges (event start/end, last modification), and event types.

Find free slots

Finds both free and busy time slots in Google Calendars for specified calendars within a defined time range.

Get Google Calendar

Retrieves a specific Google Calendar, identified by `calendar_id`, to which the authenticated user has access.

Get current date and time

Gets the current date and time, allowing for a specific timezone offset.

List Buildings

Lists all buildings for a Google Workspace customer account with full details including addresses, coordinates, and floor names.

List Calendar Resources

Retrieves calendar resources (such as conference rooms) from a Google Workspace domain using the Admin SDK Directory API.

List Google Calendars

Retrieves calendars from the user's Google Calendar list, with options for pagination and filtering.

Patch Calendar

Partially updates (PATCHes) an existing Google Calendar, modifying only the fields provided.

Patch Event

Update specified fields of an existing event in a Google Calendar using patch semantics (array fields like `attendees` are fully replaced if provided); ensure the `calendar_id` and `event_id` are valid and the user has write access to the calendar.

Quick Add Event

Parses natural language text to quickly create a basic Google Calendar event with its title, date, and time, suitable for simple scheduling; does not support direct attendee addition or recurring events, and `calendar_id` must be valid if not 'primary'.

Remove attendee from event

Removes an attendee from a specified event in a Google Calendar; the calendar and event must exist.

Get Calendar Setting

Tool to return a single user setting for the authenticated user.

List Settings

Returns all user settings for the authenticated user.

Watch Settings

Watch for changes to Settings resources.

Update Google event

Updates an existing event in Google Calendar.

FAQ

Frequently asked questions

With a standalone Google Calendar MCP server, the agents and LLMs can only access a fixed set of Google Calendar tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Google Calendar and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. OpenAI Agents SDK fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Google Calendar tools.

Yes, absolutely. You can configure which Google Calendar scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Google Calendar data and credentials are handled as safely as possible.

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