# Google Calendar

Google Calendar is a time management tool providing scheduling features, event reminders, and integration with email and other apps for streamlined organization

- **Category:** scheduling & booking
- **Auth:** OAUTH2
- **Tools:** 46
- **Triggers:** 7
- **Slug:** `GOOGLECALENDAR`
- **Version:** 20260217_00

## Frequently Asked Questions

### How do I set up custom Google OAuth credentials for Google Calendar?

For a step-by-step guide on creating and configuring your own Google OAuth credentials with Devcaster, see [How to create OAuth2 credentials for Google Apps](https://devcaster.dev/auth/googleapps).

### Why am I seeing "App is blocked" when connecting Google Calendar?

The OAuth client is requesting scopes that Google hasn't verified for that client. This usually happens when you add extra scopes beyond the defaults.

Remove the additional scopes from your auth config, or create your own OAuth app and submit the scopes for verification. See [How to create OAuth2 credentials for Google Apps](https://devcaster.dev/auth/googleapps).

### Why am I getting "Google Calendar API has not been used in project" error?

When using custom OAuth credentials, the Google Calendar API must be enabled in the Google Cloud project that owns those credentials. Enable it in Google Cloud Console under APIs & Services, wait a few minutes, and retry.

### Why am I getting "Error 400: invalid_scope"?

The requested scopes are invalid or incorrectly formatted in the authorization URL. Verify your scope values against the [Google OAuth scopes docs](https://developers.google.com/identity/protocols/oauth2). If you're creating auth configs programmatically, see the [programmatic auth config guide](/docs/auth-configuration/programmatic-auth-configs).

### Why does the OAuth consent screen show "Devcaster" instead of my app?

By default, the consent screen uses Devcaster's OAuth app. To show your own app name and logo, create your own OAuth app and set a custom redirect URL. See [White-labeling the OAuth consent screen](/docs/auth-configuration/custom-auth-configs#white-labeling-the-oauth-consent-screen).

### Why am I getting 401 errors on tool calls?

The user's access token is no longer valid. Common causes: the user revoked access, changed their password or 2FA, a Workspace admin policy changed, or Google's refresh token limit (~50 per account) was exceeded. Re-authenticating the user typically resolves this.

---

## Tools

### Delete ACL Rule

**Slug:** `GOOGLECALENDAR_ACL_DELETE`

Deletes an access control rule from a Google Calendar. Use when you need to remove sharing permissions for a user, group, or domain.

### Get ACL Rule

**Slug:** `GOOGLECALENDAR_ACL_GET`

Retrieves a specific access control rule for a calendar. Use when you need to check permissions for a specific user, group, or domain.

### Create ACL Rule

**Slug:** `GOOGLECALENDAR_ACL_INSERT`

Creates an access control rule for a calendar. Use when you need to grant sharing permissions to a user, group, or domain.

### Patch ACL Rule

**Slug:** `GOOGLECALENDAR_ACL_PATCH`

Updates an existing access control rule for a calendar using patch semantics (partial update). This allows modifying specific fields without affecting other properties. IMPORTANT: The ACL rule must already exist on the calendar. This action cannot create new rules. If you receive a 404 Not Found error, the rule does not exist - use ACL insert to create it first, or use ACL list to verify available rules. Each patch request consumes three quota units. For domain-type ACL rules, if PATCH fails with 500 error, this action will automatically fallback to UPDATE method.

### Watch ACL Changes

**Slug:** `GOOGLECALENDAR_ACL_WATCH`

Tool to watch for changes to ACL resources. Use when you need to set up real-time notifications for access control list modifications on a calendar.

### Batch Events

**Slug:** `GOOGLECALENDAR_BATCH_EVENTS`

Execute up to 1000 event mutations (create/patch/delete) in one Google Calendar HTTP batch request with per-item status/results. Use this to materially reduce round-trips for bulk operations like migrations, cleanup, or large-scale updates.

### Remove Calendar from List

**Slug:** `GOOGLECALENDAR_CALENDAR_LIST_DELETE`

Tool to remove a calendar from the user's calendar list. Use when you need to unsubscribe from or hide a calendar from the user's list.

### Get Single Calendar by ID

**Slug:** `GOOGLECALENDAR_CALENDAR_LIST_GET`

Retrieves metadata for a SINGLE specific calendar from the user's calendar list by its calendar ID. This action requires a calendarId parameter and returns details about that one calendar only. NOTE: This does NOT list all calendars. To list all calendars in the user's calendar list, use GOOGLECALENDAR_CALENDAR_LIST_LIST instead.

### Insert Calendar into List

**Slug:** `GOOGLECALENDAR_CALENDAR_LIST_INSERT`

Inserts an existing calendar into the user's calendar list.

### Patch Calendar List Entry

**Slug:** `GOOGLECALENDAR_CALENDAR_LIST_PATCH`

Updates an existing calendar on the user's calendar list using patch semantics. This method allows partial updates, modifying only the specified fields.

### Update Calendar List Entry

**Slug:** `GOOGLECALENDAR_CALENDAR_LIST_UPDATE`

Updates an existing entry on the user\'s calendar list.

### Watch Calendar List

**Slug:** `GOOGLECALENDAR_CALENDAR_LIST_WATCH`

Watch for changes to CalendarList resources using push notifications. Use this to receive real-time updates when calendar list entries are modified.

### Delete Calendar

**Slug:** `GOOGLECALENDAR_CALENDARS_DELETE`

Deletes a secondary calendar that you own or have delete permissions on. You cannot delete your primary calendar or calendars you only have read/write access to. Use calendarList.list to find calendars with owner accessRole. For primary calendars, use calendars.clear instead.

### Update Calendar

**Slug:** `GOOGLECALENDAR_CALENDARS_UPDATE`

Updates metadata for a calendar.

### Stop Channel

**Slug:** `GOOGLECALENDAR_CHANNELS_STOP`

Tool to stop watching resources through a notification channel. Use when you need to discontinue push notifications for a specific channel subscription.

### Clear Calendar

**Slug:** `GOOGLECALENDAR_CLEAR_CALENDAR`

Clears a primary calendar. This operation deletes all events associated with the primary calendar of an account.

### Get Color Definitions

**Slug:** `GOOGLECALENDAR_COLORS_GET`

Returns the color definitions for calendars and events. Use when you need to retrieve the available color palette for styling calendars or events.

### Create Event

**Slug:** `GOOGLECALENDAR_CREATE_EVENT`

Create a Google Calendar event using `start_datetime` plus `event_duration_hour` and `event_duration_minutes` fields to derive the end time. Requires calendar write access. The organizer is added as an attendee unless `exclude_organizer` is True. By default, attempts to create a Google Meet link for the event (create_meeting_room defaults to True). Workspace accounts will receive a Meet link, while personal Gmail accounts will gracefully fallback to creating an event without a Meet link when conference creation fails. Set create_meeting_room to False to explicitly skip Meet link creation. Example request to create event for 1 hour 30 minutes: { "calendar_id": "primary", "start_datetime": "2025-01-16T13:00:00", "timezone": "America/New_York", "event_duration_hour": 1, "event_duration_minutes": 30, "summary": "Client sync", "attendees": ["guest@example.com", "test@example.com"] }

### Delete event

**Slug:** `GOOGLECALENDAR_DELETE_EVENT`

Deletes a specified event by `event_id` from a Google Calendar (`calendar_id`); this action is idempotent and raises a 404 error if the event is not found.

### Create a calendar

**Slug:** `GOOGLECALENDAR_DUPLICATE_CALENDAR`

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

### Get Event

**Slug:** `GOOGLECALENDAR_EVENTS_GET`

Retrieves a SINGLE event by its unique event_id (REQUIRED). This action does NOT list or search events - it fetches ONE specific event when you already know its ID. If you want to list events within a time range, search for events, or filter by criteria like time_min/time_max, use GOOGLECALENDAR_EVENTS_LIST instead.

### Import Event

**Slug:** `GOOGLECALENDAR_EVENTS_IMPORT`

Tool to import an event as a private copy to a calendar. Use when you need to add an existing event to a calendar using its iCalUID. Only events with eventType='default' can be imported.

### Get Event Instances

**Slug:** `GOOGLECALENDAR_EVENTS_INSTANCES`

Returns instances of the specified recurring event.

### List Events

**Slug:** `GOOGLECALENDAR_EVENTS_LIST`

Returns events on the specified calendar. TIMEZONE WARNING: When using timeMin/timeMax with UTC timestamps (ending in 'Z'), the time window is interpreted in UTC regardless of the calendar's timezone. For example, querying '2026-01-19T00:00:00Z' to '2026-01-20T00:00:00Z' on a calendar in America/Los_Angeles (UTC-8) covers 2026-01-18 4pm to 2026-01-19 4pm local time, potentially missing events on the intended local date. To query for a specific local date, use timestamps with the appropriate timezone offset in timeMin/timeMax (e.g., '2026-01-19T00:00:00-08:00' for PST).

### List Events from All Calendars

**Slug:** `GOOGLECALENDAR_EVENTS_LIST_ALL_CALENDARS`

Return a unified event list across all calendars in the user's calendar list for a given time range. Use when you need a single view of all events across multiple calendars.

### Move Event

**Slug:** `GOOGLECALENDAR_EVENTS_MOVE`

Moves an event to another calendar, i.e., changes an event's organizer.

### Watch Events

**Slug:** `GOOGLECALENDAR_EVENTS_WATCH`

Watch for changes to Events resources.

### Find event

**Slug:** `GOOGLECALENDAR_FIND_EVENT`

Finds events in a specified Google Calendar using text query, time ranges (event start/end, last modification), and event types; ensure `timeMin` is not chronologically after `timeMax` if both are provided.

### Find free slots

**Slug:** `GOOGLECALENDAR_FIND_FREE_SLOTS`

Finds both free and busy time slots in Google Calendars for specified calendars within a defined time range. If `time_min` is not provided, defaults to the current timestamp in the specified timezone. If `time_max` is not provided, defaults to 23:59:59 of the day specified in `time_min` (if provided), otherwise defaults to 23:59:59 of the current day in the specified timezone. Returns busy intervals and calculates free slots by finding gaps between busy periods; `time_min` must precede `time_max` if both are provided. This action retrieves free and busy time slots for the specified calendars over a given time period. It analyzes the busy intervals from the calendars and provides calculated free slots based on the gaps in the busy periods.

### Query Free/Busy Information

**Slug:** `GOOGLECALENDAR_FREE_BUSY_QUERY`

Returns free/busy information for a set of calendars.

### Get Google Calendar

**Slug:** `GOOGLECALENDAR_GET_CALENDAR`

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

### Get Calendar Profile

**Slug:** `GOOGLECALENDAR_GET_CALENDAR_PROFILE`

Tool to retrieve the authenticated user's primary calendar profile. Use when you need to get information about the user's main calendar, including timezone, settings, and preferences.

### Get current date and time

**Slug:** `GOOGLECALENDAR_GET_CURRENT_DATE_TIME`

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

### List ACL Rules

**Slug:** `GOOGLECALENDAR_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.

### List Google Calendars

**Slug:** `GOOGLECALENDAR_LIST_CALENDARS`

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

### List Calendar Settings

**Slug:** `GOOGLECALENDAR_LIST_SETTINGS`

Tool to return all user settings for the authenticated user. Use when you need to retrieve calendar settings.

### Patch Calendar

**Slug:** `GOOGLECALENDAR_PATCH_CALENDAR`

Partially updates (PATCHes) an existing Google Calendar, modifying only the fields provided. At least one of summary, description, location, or timezone must be provided. Empty strings for `description` or `location` clear them.

### Patch Event

**Slug:** `GOOGLECALENDAR_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

**Slug:** `GOOGLECALENDAR_QUICK_ADD`

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

**Slug:** `GOOGLECALENDAR_REMOVE_ATTENDEE`

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

### Get Calendar Setting

**Slug:** `GOOGLECALENDAR_SETTINGS_GET`

Tool to return a single user setting for the authenticated user. Use when you need to retrieve a specific calendar setting value.

### List Settings

**Slug:** `GOOGLECALENDAR_SETTINGS_LIST`

Returns all user settings for the authenticated user.

### Watch Settings

**Slug:** `GOOGLECALENDAR_SETTINGS_WATCH`

Watch for changes to Settings resources.

### Sync Events

**Slug:** `GOOGLECALENDAR_SYNC_EVENTS`

Synchronizes Google Calendar events, performing a full sync if no `sync_token` is provided or if a 410 GONE error (due to an expired token) necessitates it, otherwise performs an incremental sync for events changed since the `sync_token` was issued.

### Update ACL Rule

**Slug:** `GOOGLECALENDAR_UPDATE_ACL_RULE`

Updates an access control rule for the specified calendar.

### Update Google event

**Slug:** `GOOGLECALENDAR_UPDATE_EVENT`

Updates an existing event in Google Calendar. REQUIRES event_id - you MUST first search for the event using GOOGLECALENDAR_FIND_EVENT or GOOGLECALENDAR_EVENTS_LIST to obtain the event_id. This is a full PUT replacement, so provide all desired fields as unspecified ones may be cleared or reset.


## Triggers

### Attendee Response Changed

**Slug:** `GOOGLECALENDAR_ATTENDEE_RESPONSE_CHANGED_TRIGGER`

Polling trigger that fires when any attendee's RSVP changes to
    accepted, declined, or tentative. Returns attendee info and current status.

### Event Canceled or Deleted

**Slug:** `GOOGLECALENDAR_EVENT_CANCELED_DELETED_TRIGGER`

Triggers when a Google Calendar event is cancelled or deleted.
    Returns minimal data: event_id, summary (if available), and cancellation timestamp.

### Event Starting Soon

**Slug:** `GOOGLECALENDAR_EVENT_STARTING_SOON_TRIGGER`

Triggers when a calendar event is within a configured number of minutes from starting.
    Includes countdown window, start time, and event metadata.

### Calendar Event Changes

**Slug:** `GOOGLECALENDAR_GOOGLE_CALENDAR_EVENT_CHANGE_TRIGGER`

**SOON TO BE DEPRECATED** - Use Calendar Event Sync (polling trigger) instead.
    Real-time webhook trigger for calendar event changes. Returns event metadata only.
    For full event data, use Calendar Event Sync (polling trigger).

### Event Created

**Slug:** `GOOGLECALENDAR_GOOGLE_CALENDAR_EVENT_CREATED_TRIGGER`

Polling trigger that fires when a new calendar event is created.
    Returns event ID, summary, start/end times, and organizer info.

### Calendar Event Sync

**Slug:** `GOOGLECALENDAR_GOOGLE_CALENDAR_EVENT_SYNC_TRIGGER`

Polling trigger that returns full event data including details, attendees, and metadata.
    For real-time notifications with basic info, use Calendar Event Changes (webhook).

### Event Updated

**Slug:** `GOOGLECALENDAR_GOOGLE_CALENDAR_EVENT_UPDATED_TRIGGER`

Triggers when an existing Google Calendar event is modified. Returns the event ID,
    change type, and the specific fields that changed with their previous and new values.
