Purpose

Automate Google Calendar operations including listing events, checking availability, creating meetings, and managing attendees. Particularly useful for sales teams scheduling calls, finding available slots to propose to clients, and managing recurring meetings.

Google Calendar

Read, create, and manage Google Calendar events via OAuth authentication.

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CRITICAL SAFETY RULES

These rules are MANDATORY and must NEVER be bypassed:

1. NEVER Create Events Without Explicit Approval

• ALWAYS show the user the complete event details before creating
• ALWAYS ask for explicit confirmation: "Create this event? (yes/no)"
• NEVER auto-create events, even if user says "schedule a meeting"
• NEVER create multiple events in a loop without per-event confirmation

2. Calendar Invites Alert Attendees

• When an event has attendees, creating/updating/deleting it sends notifications
• ALWAYS warn the user: "Attendees will receive a calendar invite!"
• Consider the impact before modifying events with external participants

3. Recurring Events Need Extra Care

• Modifying a recurring event can affect all instances
• WARN user when working with recurring events
• Ask whether to modify single instance or all occurrences

4. Confirm Deletions

• ALWAYS show event details before deleting
• If event has attendees: "Attendees will be notified of cancellation"
• REQUIRE explicit confirmation before delete

5. Safe Operations (No Confirmation Needed)

These do NOT require confirmation:

• List events
• Get event details
• List calendars
• Search events
• Check availability (freebusy)
• Find available slots

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Pre-Flight Check (ALWAYS RUN FIRST)

python3 00-system/skills/google/google-master/scripts/google_auth.py --check --service calendar

Exit codes:

• 0: Ready to use - proceed with user request
• 1: Need to login - run python3 00-system/skills/google/google-master/scripts/google_auth.py --login
• 2: Missing credentials or dependencies - see ../google-master/references/setup-guide.md

---

Quick Reference

List Upcoming Events

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py list --max 10

List Today's Events

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py list --from "today" --to "tomorrow"

List This Week's Events

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py list --from "2025-12-16" --to "2025-12-20"

Get Event Details

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py get <event_id>

List Calendars

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py calendars

Search Events

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py search "sales call"

Check Availability

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py freebusy --from "2025-12-16T09:00" --to "2025-12-16T17:00"

Find Available Slots (Sales Priority)

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py find-slots --duration 30 --from "2025-12-16" --to "2025-12-20" --hours "9-17"

Create Event

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py create \
  --summary "Sales Call with Acme Corp" \
  --start "2025-12-16T14:00" \
  --end "2025-12-16T14:30" \
  --attendees "john@acme.com" \
  --reminder-popup 15

Quick Add (Natural Language)

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py quick-add "Meeting with John tomorrow at 3pm"

Update Event

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py update <event_id> \
  --start "2025-12-17T15:00" \
  --end "2025-12-17T15:30"

Delete Event

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py delete <event_id>

Add Attendees

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py add-attendees <event_id> --attendees "user@example.com"

Remove Attendees

python3 00-system/skills/google/google-calendar/scripts/calendar_operations.py remove-attendees <event_id> --attendees "user@example.com"

---

Common Workflows (Sales-Focused)

Check Today's Schedule

User: "What's on my calendar today?"

1. List events for today
2. Summarize meetings with times and attendees
3. Highlight any gaps for potential meetings

from calendar_operations import list_events
from datetime import datetime, timedelta

today = datetime.now().strftime("%Y-%m-%d")
tomorrow = (datetime.now() + timedelta(days=1)).strftime("%Y-%m-%d")

events = list_events(time_min=today, time_max=tomorrow)

for event in events:
    print(f"{event['summary']} - {event['start']}")

Find Available Slots for Client

User: "Find 30-minute slots this week for a client call"

from calendar_operations import find_slots

slots = find_slots(
    duration_minutes=30,
    time_min="2025-12-16",
    time_max="2025-12-20",
    working_hours=(9, 17)
)

print("Available slots:")
for slot in slots[:5]:
    print(f"  {slot['start']} - {slot['end']}")

Schedule a Sales Call

User: "Schedule a call with john@acme.com tomorrow at 2pm"

from calendar_operations import create_event

event = create_event(
    summary="Sales Call - Acme Corp",
    start="2025-12-17T14:00",
    end="2025-12-17T14:30",
    attendees=["john@acme.com"],
    reminders={'popup': 15},
    description="Discovery call to discuss needs"
)

print(f"Created: {event['htmlLink']}")

Reschedule a Meeting

User: "Move the Acme call to Thursday at 3pm"

from calendar_operations import update_event

result = update_event(
    event_id="abc123",
    start="2025-12-19T15:00",
    end="2025-12-19T15:30"
)
# Attendees are automatically notified

Set Up Recurring Check-ins

User: "Set up weekly calls with the client every Tuesday at 10am"

from calendar_operations import create_event

event = create_event(
    summary="Weekly Check-in - Acme Corp",
    start="2025-12-17T10:00",
    end="2025-12-17T10:30",
    attendees=["john@acme.com"],
    recurrence=["RRULE:FREQ=WEEKLY;BYDAY=TU;COUNT=12"],
    reminders={'popup': 15}
)

Check If Free for a Meeting

User: "Am I free Thursday at 2pm?"

from calendar_operations import get_freebusy

result = get_freebusy(
    time_min="2025-12-19T14:00",
    time_max="2025-12-19T15:00"
)

if result['primary']['is_free']:
    print("Yes, that time is available!")
else:
    print("You have a conflict during that time")

---

Available Operations

Operation	Function	Description
List	list_events()	List upcoming events with filters
Get	get_event()	Get full event details
Calendars	list_calendars()	List all accessible calendars
Search	search_events()	Search events by keyword
FreeBusy	get_freebusy()	Check availability for time range
Find Slots	find_slots()	Find available meeting slots
Create	create_event()	Create new event
Quick Add	quick_add()	Create from natural language
Update	update_event()	Modify existing event
Delete	delete_event()	Delete event
Add Attendees	add_attendees()	Add people to event
Remove Attendees	remove_attendees()	Remove people from event

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Recurrence Rules

Use RRULE format for recurring events:

Pattern	RRULE
Daily	RRULE:FREQ=DAILY
Weekly	RRULE:FREQ=WEEKLY
Every Tuesday	RRULE:FREQ=WEEKLY;BYDAY=TU
Bi-weekly	RRULE:FREQ=WEEKLY;INTERVAL=2
Monthly	RRULE:FREQ=MONTHLY
10 occurrences	RRULE:FREQ=WEEKLY;COUNT=10
Until date	RRULE:FREQ=WEEKLY;UNTIL=20251231T000000Z

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Error Handling

See ../google-master/references/error-handling.md for common errors and solutions.

Error	Cause	Solution
401 Unauthorized	Token expired	Run google_auth.py --login
403 Forbidden	No access to calendar	Check calendar sharing settings
404 Not Found	Wrong event/calendar ID	Verify the ID is correct
"Access blocked"	User not in test users	Add to OAuth consent screen test users
Rate limit exceeded	Too many requests	Wait and retry

---

Python Import Usage

import sys
sys.path.insert(0, "03-skills/google-calendar/scripts")

from calendar_operations import (
    list_events,
    get_event,
    list_calendars,
    search_events,
    get_freebusy,
    find_slots,
    create_event,
    quick_add,
    update_event,
    delete_event,
    add_attendees,
    remove_attendees
)

# List upcoming events
events = list_events(max_results=5)

# Find available 30-min slots
slots = find_slots(
    duration_minutes=30,
    time_min="2025-12-16",
    time_max="2025-12-20"
)

# Create event with attendee
event = create_event(
    summary="Sales Call",
    start="2025-12-17T14:00",
    end="2025-12-17T14:30",
    attendees=["client@company.com"],
    reminders={'popup': 15}
)

# Check availability
freebusy = get_freebusy(
    time_min="2025-12-17T09:00",
    time_max="2025-12-17T17:00"
)

---

Calendar Selection

By default, all operations use the primary calendar. To use a different calendar:

# List events from a specific calendar
python calendar_operations.py list --calendar "work@group.calendar.google.com"

# Create event on specific calendar
python calendar_operations.py create --calendar "sales@company.com" --summary "Team Meeting" ...

To find available calendar IDs:

python calendar_operations.py calendars

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Setup

First-time setup: ../google-master/references/setup-guide.md

Quick start:

1. pip install google-auth google-auth-oauthlib google-api-python-client
2. Create OAuth credentials in Google Cloud Console (enable Google Calendar API, choose "Desktop app")
3. Add to .env file at Nexus root:

   GOOGLE_CLIENT_ID=your-client-id.apps.googleusercontent.com
   GOOGLE_CLIENT_SECRET=your-client-secret
   GOOGLE_PROJECT_ID=your-project-id
   

4. Run python3 00-system/skills/google/google-master/scripts/google_auth.py --login

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Security Notes

Permission Scope

• Read permissions - Can view all calendars and events
• Write permissions - Can create, modify, delete events
• Tokens stored locally - In 01-memory/integrations/google-token.json

Data Privacy

• Event data is processed locally, not stored
• Tokens grant access only to the authenticated user's calendars
• Sharing the skill does NOT give others access to your calendar
• Each team member authenticates with their own Google account