Google Calendar Automation via Rube MCP

Automate Google Calendar workflows including event creation, scheduling, availability checks, attendee management, and calendar browsing through Composio's Google Calendar toolkit.

Prerequisites

Rube MCP must be connected (RUBE_SEARCH_TOOLS available)
Active Google Calendar connection via
```
RUBE_MANAGE_CONNECTIONS
```
with toolkit
```
googlecalendar
```
Always call
```
RUBE_SEARCH_TOOLS
```
first to get current tool schemas

Setup

Get Rube MCP: Add

https://rube.app/mcp

as an MCP server in your client configuration. No API keys needed — just add the endpoint and it works.

Verify Rube MCP is available by confirming
```
RUBE_SEARCH_TOOLS
```
responds
Call
```
RUBE_MANAGE_CONNECTIONS
```
with toolkit
```
googlecalendar
```
If connection is not ACTIVE, follow the returned auth link to complete Google OAuth
Confirm connection status shows ACTIVE before running any workflows

Core Workflows

1. Create and Manage Events

When to use: User wants to create, update, or delete calendar events

Tool sequence:

```
GOOGLECALENDAR_LIST_CALENDARS
```
- Identify target calendar ID [Prerequisite]
```
GOOGLECALENDAR_GET_CURRENT_DATE_TIME
```
- Get current time with proper timezone [Optional]
```
GOOGLECALENDAR_FIND_FREE_SLOTS
```
- Check availability before booking [Optional]
```
GOOGLECALENDAR_CREATE_EVENT
```
- Create the event [Required]
```
GOOGLECALENDAR_PATCH_EVENT
```
- Update specific fields of an existing event [Alternative]
```
GOOGLECALENDAR_UPDATE_EVENT
```
- Full replacement update of an event [Alternative]
```
GOOGLECALENDAR_DELETE_EVENT
```
- Delete an event [Optional]

Key parameters:

```
calendar_id
```
: Use 'primary' for main calendar, or specific calendar ID
```
start_datetime
```
: ISO 8601 format 'YYYY-MM-DDTHH:MM:SS' (NOT natural language)
```
timezone
```
: IANA timezone name (e.g., 'America/New_York', NOT 'EST' or 'PST')
```
event_duration_hour
```
: Hours (0+)
```
event_duration_minutes
```
: Minutes (0-59 only; NEVER use 60+)
```
summary
```
: Event title
```
attendees
```
: Array of email addresses (NOT names)
```
location
```
: Free-form text for event location

Pitfalls:

```
start_datetime
```
must be ISO 8601; natural language like 'tomorrow' is rejected

event_duration_minutes

max is 59; use

event_duration_hour=1

instead of

event_duration_minutes=60

```
timezone
```
must be IANA identifier; abbreviations like 'EST', 'PST' are NOT valid
```
attendees
```
only accepts email addresses, not names; resolve names first
Google Meet link creation defaults to true; may fail on personal Gmail accounts (graceful fallback)
Organizer is auto-added as attendee unless
```
exclude_organizer=true
```

2. List and Search Events

When to use: User wants to find or browse events on their calendar

Tool sequence:

```
GOOGLECALENDAR_LIST_CALENDARS
```
- Get available calendars [Prerequisite]
```
GOOGLECALENDAR_FIND_EVENT
```
- Search by title/keyword with time bounds [Required]
```
GOOGLECALENDAR_EVENTS_LIST
```
- List events in a time range [Alternative]
```
GOOGLECALENDAR_EVENTS_INSTANCES
```
- List instances of a recurring event [Optional]

Key parameters:

```
query
```
/
```
q
```
: Free-text search (matches summary, description, location, attendees)
```
timeMin
```
: Lower bound (RFC3339 with timezone offset, e.g., '2024-01-01T00:00:00-08:00')
```
timeMax
```
: Upper bound (RFC3339 with timezone offset)
```
singleEvents
```
: true to expand recurring events into instances
```
orderBy
```
: 'startTime' (requires singleEvents=true) or 'updated'
```
maxResults
```
: Results per page (max 2500)

Pitfalls:

Timezone warning: UTC timestamps (ending in 'Z') don't align with local dates; use local timezone offsets instead
Example: '2026-01-19T00:00:00Z' covers 2026-01-18 4pm to 2026-01-19 4pm in PST
Omitting
```
timeMin
```
/
```
timeMax
```
scans the full calendar and can be slow
```
pageToken
```
in response means more results; paginate until absent
```
orderBy='startTime'
```
requires
```
singleEvents=true
```

3. Manage Attendees and Invitations

When to use: User wants to add, remove, or update event attendees

Tool sequence:

GOOGLECALENDAR_FIND_EVENT

GOOGLECALENDAR_EVENTS_LIST

- Find the event [Prerequisite]

```
GOOGLECALENDAR_PATCH_EVENT
```
- Add attendees (replaces entire attendees list) [Required]
```
GOOGLECALENDAR_REMOVE_ATTENDEE
```
- Remove a specific attendee by email [Required]

Key parameters:

```
event_id
```
: Unique event identifier (opaque string, NOT the event title)
```
attendees
```
: Full list of attendee emails (PATCH replaces entire list)
```
attendee_email
```
: Email to remove
```
send_updates
```
: 'all', 'externalOnly', or 'none'

Pitfalls:

```
event_id
```
is a technical identifier, NOT the event title; always search first to get the ID
```
PATCH_EVENT
```
attendees field replaces the entire list; include existing attendees to avoid removing them
Attendee names cannot be resolved; always use email addresses
Use
```
GMAIL_SEARCH_PEOPLE
```
to resolve names to emails before managing attendees

4. Check Availability and Free/Busy Status

When to use: User wants to find available time slots or check busy periods

Tool sequence:

```
GOOGLECALENDAR_LIST_CALENDARS
```
- Identify calendars to check [Prerequisite]
```
GOOGLECALENDAR_GET_CURRENT_DATE_TIME
```
- Get current time with timezone [Optional]
```
GOOGLECALENDAR_FIND_FREE_SLOTS
```
- Find free intervals across calendars [Required]
```
GOOGLECALENDAR_FREE_BUSY_QUERY
```
- Get raw busy periods for computing gaps [Fallback]
```
GOOGLECALENDAR_CREATE_EVENT
```
- Book a confirmed slot [Required]

Key parameters:

```
items
```
: List of calendar IDs to check (e.g., ['primary'])
```
time_min
```
/
```
time_max
```
: Query interval (defaults to current day if omitted)
```
timezone
```
: IANA timezone for interpreting naive timestamps
```
calendarExpansionMax
```
: Max calendars (1-50)
```
groupExpansionMax
```
: Max members per group (1-100)

Pitfalls:

Maximum span ~90 days per Google Calendar freeBusy API limit
Very long ranges or inaccessible calendars yield empty/invalid results
Only calendars with at least freeBusyReader access are visible
Free slots responses may normalize to UTC ('Z'); check offsets
```
GOOGLECALENDAR_FREE_BUSY_QUERY
```
requires RFC3339 timestamps with timezone

Common Patterns

ID Resolution

Calendar name -> calendar_id:
```
GOOGLECALENDAR_LIST_CALENDARS
```
to enumerate all calendars

Event title -> event_id:

GOOGLECALENDAR_FIND_EVENT

GOOGLECALENDAR_EVENTS_LIST

Attendee name -> email:
```
GMAIL_SEARCH_PEOPLE
```

Timezone Handling

Always use IANA timezone identifiers (e.g., 'America/Los_Angeles')
Use
```
GOOGLECALENDAR_GET_CURRENT_DATE_TIME
```
to get current time in user's timezone
When querying events for a local date, use timestamps with local offset, NOT UTC
Example: '2026-01-19T00:00:00-08:00' for PST, NOT '2026-01-19T00:00:00Z'

Pagination

```
GOOGLECALENDAR_EVENTS_LIST
```
returns
```
nextPageToken
```
; iterate until absent
```
GOOGLECALENDAR_LIST_CALENDARS
```
also paginates; use
```
page_token
```

Known Pitfalls

Natural language dates: NOT supported; all dates must be ISO 8601 or RFC3339
Timezone mismatch: UTC timestamps don't align with local dates for filtering
Duration limits:
```
event_duration_minutes
```
max 59; use hours for longer durations
IANA timezones only: 'EST', 'PST', etc. are NOT valid; use 'America/New_York'
Event IDs are opaque: Always search to get event_id; never guess or construct
Attendees as emails: Names cannot be used; resolve with GMAIL_SEARCH_PEOPLE
PATCH replaces attendees: Include all desired attendees in the array, not just new ones
Conference limitations: Google Meet may fail on personal accounts (graceful fallback)
Rate limits: High-volume searches can trigger 403/429; throttle between calls

Quick Reference

Task	Tool Slug	Key Params
List calendars	`GOOGLECALENDAR_LIST_CALENDARS`	`max_results`
Create event	`GOOGLECALENDAR_CREATE_EVENT`	`start_datetime` , `timezone` , `summary`
Update event	`GOOGLECALENDAR_PATCH_EVENT`	`calendar_id` , `event_id` , fields to update
Delete event	`GOOGLECALENDAR_DELETE_EVENT`	`calendar_id` , `event_id`
Search events	`GOOGLECALENDAR_FIND_EVENT`	`query` , `timeMin` , `timeMax`
List events	`GOOGLECALENDAR_EVENTS_LIST`	`calendarId` , `timeMin` , `timeMax`
Recurring instances	`GOOGLECALENDAR_EVENTS_INSTANCES`	`calendarId` , `eventId`
Find free slots	`GOOGLECALENDAR_FIND_FREE_SLOTS`	`items` , `time_min` , `time_max` , `timezone`
Free/busy query	`GOOGLECALENDAR_FREE_BUSY_QUERY`	`timeMin` , `timeMax` , `items`
Remove attendee	`GOOGLECALENDAR_REMOVE_ATTENDEE`	`event_id` , `attendee_email`
Get current time	`GOOGLECALENDAR_GET_CURRENT_DATE_TIME`	`timezone`
Get calendar	`GOOGLECALENDAR_GET_CALENDAR`	`calendar_id`

google-calendar-automation

NPX Install

Tags

SKILL.md Content

Google Calendar Automation via Rube MCP

Prerequisites

Setup

Core Workflows

1. Create and Manage Events

2. List and Search Events

3. Manage Attendees and Invitations

4. Check Availability and Free/Busy Status

Common Patterns

ID Resolution

Timezone Handling

Pagination

Known Pitfalls

Quick Reference