Google Calendar Management

Three access methods, in order of preference:

1. gcallm CLI (Creating Events)

Best for creating events from natural language or file input.

bash

# Direct text
gcallm "Meeting with Sarah tomorrow at 3pm"

# From file (preferred for multi-event)
cat /tmp/gcal/events.txt | gcallm

# From clipboard
gcallm

# From screenshot
gcallm -s "Add events from this screenshot"

# Ask questions
gcallm ask "What's on my calendar today?"
gcallm ask "Am I free Thursday afternoon?"

2. MCP Tools (Full CRUD When Available)

When the google-calendar MCP server is connected, these tools are available:

code

mcp__google-calendar__list-events    # List events in a time range
mcp__google-calendar__search-events  # Search by query string
mcp__google-calendar__create-event   # Create event
mcp__google-calendar__update-event   # Update event (supports recurring with modificationScope)
mcp__google-calendar__delete-event   # Delete event

Updating Recurring Events

Use modificationScope to control which instances are affected:

•all — update/delete the entire series
•this — only this instance
•thisAndFollowing — this and all future instances

Color IDs

ID	Color
1	Lavender
2	Sage
3	Grape
4	Flamingo
5	Banana
6	Tangerine
7	Peacock
8	Graphite
9	Blueberry
10	Basil
11	Tomato (Red)

3. Direct Google Calendar API (Fallback)

When MCP tools are unavailable, use the REST API with stored OAuth tokens.

Token Location

code

/Users/wz/.config/google-calendar-mcp/tokens.json

Read Token

bash

TOKEN=$(python3 -c "import json; print(json.load(open('/Users/wz/.config/google-calendar-mcp/tokens.json'))['normal']['access_token'])")

Common API Calls

bash

# List events
curl -s -H "Authorization: Bearer $TOKEN" \
  "https://www.googleapis.com/calendar/v3/calendars/primary/events?timeMin=2026-01-01T00:00:00Z&timeMax=2026-12-31T23:59:59Z&singleEvents=true"

# Search events
curl -s -H "Authorization: Bearer $TOKEN" \
  "https://www.googleapis.com/calendar/v3/calendars/primary/events?q=SEARCH_TERM&timeMin=...&timeMax=...&singleEvents=true"

# Create event
curl -s -X POST -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  "https://www.googleapis.com/calendar/v3/calendars/primary/events" \
  -d '{"summary":"Event Title","location":"Place","colorId":"11","start":{"dateTime":"2026-02-03T09:00:00","timeZone":"America/New_York"},"end":{"dateTime":"2026-02-03T10:00:00","timeZone":"America/New_York"},"recurrence":["RRULE:FREQ=WEEKLY;COUNT=16;BYDAY=TU"]}'

# Update event (single instance)
curl -s -X PATCH -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  "https://www.googleapis.com/calendar/v3/calendars/primary/events/EVENT_ID" \
  -d '{"colorId":"11"}'

# Delete event (entire recurring series — use base recurring event ID, no instance suffix)
curl -s -X DELETE -H "Authorization: Bearer $TOKEN" \
  "https://www.googleapis.com/calendar/v3/calendars/primary/events/RECURRING_EVENT_ID"

# Delete single instance
curl -s -X DELETE -H "Authorization: Bearer $TOKEN" \
  "https://www.googleapis.com/calendar/v3/calendars/primary/events/EVENT_ID_WITH_INSTANCE_SUFFIX"

Recurring Event IDs

•Base ID: abc123 — represents the series
•Instance ID: abc123_20260203T140000Z — represents one occurrence
•Deleting/updating the base ID affects all instances
•Each instance has recurringEventId pointing back to the base

RRULE Examples

code

RRULE:FREQ=WEEKLY;COUNT=16;BYDAY=TU          # Every Tuesday for 16 weeks
RRULE:FREQ=WEEKLY;COUNT=16;BYDAY=MO,WE       # Mon & Wed for 16 weeks
RRULE:FREQ=WEEKLY;COUNT=16;BYDAY=TU,TH       # Tue & Thu for 16 weeks
RRULE:FREQ=DAILY;COUNT=5                      # Daily for 5 days
RRULE:FREQ=WEEKLY;UNTIL=20260530T000000Z      # Weekly until date

HTTP Status Codes

Code	Meaning
200	Success (GET/PATCH)
204	Success (DELETE)
401	Token expired — need to refresh or re-auth via MCP server
404	Event not found
409	Conflict (duplicate)

Warren's Calendar

•Account: wzhu@college.harvard.edu
•Timezone: America/New_York
•Calendar ID: primary