How to integrate Google Calendar MCP with ChatGPT

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How to integrate Google Calendar MCP with ChatGPT

ChatGPT is one of the most popular AI tools today, with capabilities ranging from deep research and image generation to writing, coding, and everyday productivity.

In this guide, I will explain the easiest and most secure way to connect your Google Calendar account to ChatGPT via Composio Connect, so it can summarize unread updates from this morning, create draft replies to urgent messages, fetch contact details for recent senders, and more without ever putting your account credentials at risk.

Also integrate Google Calendar with

Why use Composio over default connectors?

  • Apps with read and write access. Default connectors mostly can read your data. Composio's Google Calendar integration lets ChatGPT take actions like creating drafts, sending updates, labeling records, and more.
  • 1,000+ SaaS toolkits out of the box. Composio gives you instant access to a vast catalog of pre-built connectors, from Gmail and Slack to Notion, Linear, and Salesforce.
  • One MCP server for every app. Connect any of your applications on demand through a single endpoint, rather than juggling a separate server for each app.
  • Smart, context-aware tool loading. Unlike traditional MCP servers that dump every available tool into the LLM context window, Composio searches for and loads only the tools relevant to the task at hand.
  • Cross-app automation. Chain actions across multiple apps in a single run - fetch a thread, summarize it in Notion, and post highlights to Slack without leaving the conversation.

Prerequisites

  • A ChatGPT account with Plus subscription or higher (Business, Enterprise, Edu, or Pro). We will use ChatGPT Web.
  • Access to the Google Calendar workspace you want to connect.
  • Composio MCP.

Note: Composio connects through OAuth. You will be asked to sign in and approve specific permissions. Review the permission screen carefully if you are using a work account.

Step-by-step: Connect Google Calendar to ChatGPT

1. Enable Developer Mode

In ChatGPT, go to Settings > Apps > Advanced settings and turn on Developer Mode.

ChatGPT settings showing Developer Mode toggle

2. Add the MCP server

Click Create app, then paste the Composio MCP server URL:

bash
https://connect.composio.dev/mcp
ChatGPT create app flow with Composio MCP URL

3. Authorize in your browser

A browser window will open automatically. Sign in to authorize ChatGPT to access your Composio account.

Composio authorization screen for ChatGPT MCP setup

4. Start using Composio

Composio tools are now available in ChatGPT chats and Deep Research. In every new chat, click the + icon at the bottom, click More, and select Composio to enable tools for that conversation.

What you can do after connecting Google Calendar

  • Create a meeting with the marketing team
  • List all events scheduled for next week
  • Delete tomorrow’s canceled event from your calendar
  • Update the time for Friday’s project sync

Security + privacy notes (important)

  • Use least-privilege access: Only grant permissions you actually need.
  • Review OAuth permissions before approving: Make sure requested scopes match what you expect Composio and ChatGPT to do.
  • Keep write actions human-reviewed: For actions like sending messages, creating labels, or editing drafts, keep manual confirmation enabled.
  • Be careful with sensitive data: Avoid using this setup with highly sensitive information unless allowed by your personal, company, or client policies.

Supported Tools & Triggers

Tools
Triggers
Delete ACL RuleDeletes an access control rule from a Google Calendar.
Get ACL RuleRetrieves a specific access control rule for a calendar.
Create ACL RuleCreates an access control rule for a calendar.
List ACL RulesRetrieves 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 RuleUpdates an existing access control rule for a calendar using patch semantics (partial update).
Update ACL RuleUpdates an access control rule for the specified calendar.
Watch ACL ChangesTool to watch for changes to ACL resources.
Batch EventsExecute up to 1000 event mutations (create/patch/delete) in one Google Calendar HTTP batch request with per-item status/results.
Remove Calendar from ListTool to remove a calendar from the user's calendar list.
Get Single Calendar by IDRetrieves metadata for a SINGLE specific calendar from the user's calendar list by its calendar ID.
Insert Calendar into ListInserts an existing calendar into the user's calendar list, making it visible in the UI.
Patch Calendar List EntryUpdates an existing calendar on the user's calendar list using patch semantics.
Update Calendar List EntryUpdates 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 ListWatch for changes to CalendarList resources using push notifications.
Delete CalendarDeletes a secondary calendar that you own or have delete permissions on.
Update CalendarFull PUT-style update that overwrites all calendar metadata fields; unspecified optional fields are cleared.
Stop ChannelTool to stop watching resources through a notification channel.
Clear CalendarClears a primary calendar by deleting all events from it.
Get Color DefinitionsReturns the color definitions for calendars and events.
Create EventCreate a Google Calendar event using start_datetime plus duration fields.
Delete eventDeletes 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 calendarCreates a new, empty Google Calendar with the specified title (summary).
Get EventRetrieves a SINGLE event by its unique event_id (REQUIRED).
Import EventTool to import an event as a private copy to a calendar.
Get Event InstancesReturns instances of the specified recurring event.
List EventsReturns events on the specified calendar.
List Events from All CalendarsReturn a unified event list across all calendars in the user's calendar list for a given time range.
Move EventMoves an event to another calendar, i.
Watch EventsWatch for changes to Events resources.
Find eventFinds events in a specified Google Calendar using text query, time ranges (event start/end, last modification), and event types.
Find free slotsFinds both free and busy time slots in Google Calendars for specified calendars within a defined time range.
Get Google CalendarRetrieves a specific Google Calendar, identified by `calendar_id`, to which the authenticated user has access.
Get current date and timeGets the current date and time, allowing for a specific timezone offset.
List BuildingsLists all buildings for a Google Workspace customer account with full details including addresses, coordinates, and floor names.
List Calendar ResourcesRetrieves calendar resources (such as conference rooms) from a Google Workspace domain using the Admin SDK Directory API.
List Google CalendarsRetrieves calendars from the user's Google Calendar list, with options for pagination and filtering.
Patch CalendarPartially updates (PATCHes) an existing Google Calendar, modifying only the fields provided.
Patch EventUpdate 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 EventParses 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 eventRemoves an attendee from a specified event in a Google Calendar; the calendar and event must exist.
Get Calendar SettingTool to return a single user setting for the authenticated user.
List SettingsReturns all user settings for the authenticated user.
Watch SettingsWatch for changes to Settings resources.
Update Google eventUpdates an existing event in Google Calendar.

How to build Google Calendar MCP Agent with another framework

FAQ

What are the differences in Tool Router MCP and Google Calendar MCP?

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.

Can I use Tool Router MCP with ChatGPT?

Yes, you can. ChatGPT 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.

Can I manage the permissions and scopes for Google Calendar while using Tool Router?

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.

How safe is my data with Composio Tool Router?

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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Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

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