Radicale CalDAV/CardDAV Management

⚠️ MANDATORY SKILL INVOCATION ⚠️

YOU MUST invoke this skill (NOT optional) when the user mentions ANY of these triggers:

"list my calendar", "what's on my calendar", "show me my events", "calendar this week", "when is my next event"
"add to my calendar", "create an event", "schedule event", "schedule a meeting"
"delete an event", "cancel event", "remove event"
"find a contact", "what's someone's email", "search my contacts", "who is"
"add a contact", "create contact", "save contact", "save someone's phone number"
Any mention of Radicale, CalDAV, CardDAV, calendar events, or contact management

Failure to invoke this skill when triggers occur violates your operational requirements.

Manage calendars (events) and contacts on a self-hosted Radicale server using CalDAV and CardDAV protocols.

Type: Read & Write (calendar events and contacts)

Purpose

This skill enables comprehensive calendar and contact management through a self-hosted Radicale server. It provides read and write access to:

Calendars - List, view, create, update, and delete calendar events
Contacts - List, search, create, update, and delete contacts in addressbooks

All operations use the Python caldav library which implements the CalDAV (RFC 4791) and CardDAV (RFC 6352) protocols.

Setup

Prerequisites

Install required Python libraries:

pip install caldav vobject icalendar

Script Permissions:

The Python script can be made executable (optional but recommended):

chmod +x ~/claude-homelab/skills/radicale/scripts/radicale-api.py

You can then run it directly:

./scripts/radicale-api.py --help

Or without executable permissions using Python:

python scripts/radicale-api.py --help

Credentials

Add to ~/.homelab-skills/.env:

RADICALE_URL="http://localhost:5232"
RADICALE_USERNAME="admin"
RADICALE_PASSWORD="password"

Security:

.env file is gitignored (never commit credentials)
Set permissions: chmod 600 ~/.homelab-skills/.env

Core Operations

All operations use the scripts/radicale-api.py wrapper script. Output is JSON format for easy parsing.

Calendar Operations

List Calendars

python scripts/radicale-api.py calendars list

Returns array of calendars with name, URL, and ID.

View Events

List events in a calendar within a date range:

python scripts/radicale-api.py events list \
  --calendar "Personal" \
  --start "2026-02-08" \
  --end "2026-02-15"

Parameters:

--calendar (required) - Calendar name (case-sensitive)
--start (optional) - Start date (YYYY-MM-DD or YYYY-MM-DDTHH:MM:SS)
--end (optional) - End date (YYYY-MM-DD or YYYY-MM-DDTHH:MM:SS)

Default behavior: If start/end not specified, uses current date + 7 days.

Returns array of events with UID, summary, description, location, start, end, and timestamps.

Create Event

python scripts/radicale-api.py events create \
  --calendar "Personal" \
  --title "Meeting" \
  --start "2026-02-10T14:00:00" \
  --end "2026-02-10T15:00:00" \
  --location "Conference Room" \
  --description "Team sync"

Required parameters:

--calendar - Calendar name
--title - Event title/summary
--start - Start datetime (YYYY-MM-DDTHH:MM:SS)
--end - End datetime (YYYY-MM-DDTHH:MM:SS)

Optional parameters:

--location - Event location
--description - Event description

Important: Use ISO 8601 datetime format (YYYY-MM-DDTHH:MM:SS). End must be after start.

Delete Event

python scripts/radicale-api.py events delete \
  --calendar "Personal" \
  --uid "event-uid-here"

Get UID from events list output.

Contact Operations

List Addressbooks

python scripts/radicale-api.py contacts addressbooks

Returns array of addressbooks with name, URL, and ID.

List Contacts

python scripts/radicale-api.py contacts list \
  --addressbook "Contacts"

Returns array of contacts with UID, name, email, and phone.

Search Contacts

python scripts/radicale-api.py contacts search \
  --addressbook "Contacts" \
  --query "David"

Search behavior: Case-insensitive substring match against name and email fields.

Create Contact

python scripts/radicale-api.py contacts create \
  --addressbook "Contacts" \
  --name "John Doe" \
  --email "john@example.com" \
  --phone "+1-555-1234"

Required parameter:

--name - Contact full name

Optional parameters:

--email - Email address
--phone - Phone number

Delete Contact

python scripts/radicale-api.py contacts delete \
  --addressbook "Contacts" \
  --uid "contact-uid-here"

Get UID from contacts list or contacts search output.

Natural Language Translation

When users make natural language requests, translate them to script commands:

Calendar Examples

User: "What's my calendar look like this week?"

Action:

Calculate current week date range
Run: python scripts/radicale-api.py events list --calendar "Personal" --start "YYYY-MM-DD" --end "YYYY-MM-DD"
Present events in human-readable format

User: "Add to my calendar Billy Strings in Athens, GA 02/07/2026 7PM EST"

Action:

Parse: title="Billy Strings", location="Athens, GA", start="2026-02-07T19:00:00", end="2026-02-07T23:00:00" (assume 4hr concert)
Run: python scripts/radicale-api.py events create --calendar "Personal" --title "Billy Strings" --start "2026-02-07T19:00:00" --end "2026-02-07T23:00:00" --location "Athens, GA"
Confirm creation

Contact Examples

User: "What's David Ryan's work email?"

Action:

Run: python scripts/radicale-api.py contacts search --addressbook "Contacts" --query "David Ryan"
Extract email field from results
Present: "David Ryan's email is david.ryan@example.com"

User: "Add John Doe to my contacts, email john@example.com"

Action:

Run: python scripts/radicale-api.py contacts create --addressbook "Contacts" --name "John Doe" --email "john@example.com"
Confirm creation

Decision Tree

When user mentions calendars or contacts:

Determine operation type:
- Calendar query ("show", "list", "what's on") → Use events list
- Calendar create ("add", "create event", "schedule") → Use events create
- Calendar delete ("remove", "delete", "cancel") → Use events delete
- Contact query ("find", "search", "what's", "who is") → Use contacts search
- Contact create ("add contact", "save contact") → Use contacts create
- Contact delete ("remove contact", "delete contact") → Use contacts delete
Identify target:
- Calendar operations → Ask which calendar (default: "Personal")
- Contact operations → Ask which addressbook (default: "Contacts")
Extract parameters:
- For events: Parse title, location, date/time from natural language
- For contacts: Parse name, email, phone from natural language
Execute command:
- Run appropriate script command
- Parse JSON output
Present results:
- Format JSON as human-readable text
- Include relevant details (event times, contact info)
- Confirm successful operations

Date/Time Handling

Important considerations:

All times are local to the Radicale server timezone
Use ISO 8601 format for consistency: YYYY-MM-DDTHH:MM:SS
When user specifies "7PM EST", convert to 24-hour local time
For all-day events, use same date for start/end with different times
Default event duration: 1 hour (if user doesn't specify end time)

Common translations:

"this week" → Calculate Mon-Sun dates from current date
"next week" → Calculate Mon-Sun dates for following week
"today" → Current date
"tomorrow" → Current date + 1 day
"7PM" → "19:00:00"
"noon" → "12:00:00"

Bundled Resources

scripts/radicale-api.py

Complete Python wrapper for CalDAV/CardDAV operations. Uses caldav library to connect to Radicale server and perform all calendar/contact operations.

Key features:

Loads credentials from .env file
JSON output for all operations
Error handling with clear messages
Supports all CalDAV/CardDAV operations

Direct usage: Can be called directly with command-line arguments (see examples above).

references/caldav-library.md

In-depth guide to the Python caldav library including:

Authentication patterns
Calendar operations (create, read, update, delete)
Event operations with iCalendar format
Contact operations with vCard format
Error handling patterns
Best practices

When to reference: When implementing custom operations beyond the wrapper script, or when debugging library-specific issues.

references/quick-reference.md

Quick command examples for all operations with sample inputs and outputs.

When to reference: When user needs examples or when uncertain about command syntax.

references/troubleshooting.md

Common errors and solutions including:

Installation issues
Connection problems
Authentication failures
Calendar/contact not found errors
Date/time format issues
Permission problems

When to reference: When operations fail or user reports errors.

Error Handling

All operations return JSON with status. Check for:

Connection errors:

ERROR: .env file not found → Guide user to create .env file
ERROR: Failed to connect to Radicale → Check Radicale is running, verify URL
ERROR: Authentication failed → Verify credentials in .env

Resource errors:

ERROR: Calendar 'X' not found → List available calendars with calendars list
ERROR: Addressbook 'X' not found → List addressbooks with contacts addressbooks

Data errors:

ValueError: Invalid isoformat string → Fix datetime format to ISO 8601
End time before start time → Adjust end time to be after start

Notes

Read-Write Operations:

All operations modify data on the Radicale server
Event creation is immediate (no confirmation prompt)
Contact creation is immediate (no confirmation prompt)
Deletions are permanent (no undo)

Performance:

Use date ranges for event queries to avoid loading all events
Search contacts instead of listing all when looking for specific person
Calendar/contact listing can be slow with large datasets

Limitations:

No timezone support in current implementation (uses local time)
No recurring event support yet
Contact fields limited to name, email, phone (vCard supports more)
No event reminders/alarms

Security:

All credentials stored in .env file (gitignored)
API script never logs credentials
Connection uses HTTP basic auth (HTTPS recommended for production)

Reference Documentation

Bundled references (load as needed):

references/caldav-library.md - Python caldav library guide
references/quick-reference.md - Command examples
references/troubleshooting.md - Error solutions

External documentation:

Radicale Documentation
caldav Library Docs
RFC 4791 - CalDAV (embedded in vector DB)
RFC 6352 - CardDAV (embedded in vector DB)

Query embedded documentation:

cd /home/jmagar/claude-homelab/skills/firecrawl
firecrawl query "CalDAV create event example"