Open Source · MCP Server · Agent Skills
The Calendar MCP Server That Doesn't Double-Book
Atomic booking, computed availability, and deterministic time math for AI agents. Every other Calendar MCP server is a CRUD wrapper. Temporal Cortex locks the slot before booking it.
Why do AI agents keep double-booking your calendar?
~60%
LLM date/time hallucination rate
LLMs hallucinate approximately 60% of date/time tasks. (AuthenHallu, arxiv 2510.10539)
0
MCP servers with locking
Most Calendar MCP servers are thin CRUD wrappers — no locking, no conflict detection, no availability computation.
3+
Calendar silos per person
Your calendars are fragmented — Google for work, Outlook for enterprise, iCloud for personal. Agents inherit this blindness.
Three things no other Calendar MCP server does
Atomic Booking (2PC)
Lock → verify → write → release. If any step fails, everything rolls back. Zero double-bookings, even with concurrent agents.
book_slot({
calendar_id: "primary",
title: "Team Sync",
start: "2026-02-26T14:00",
end: "2026-02-26T15:00"
})
// Lock acquired → conflict check → booked ✓Truth Engine
Deterministic RRULE expansion. Handles DST transitions, BYSETPOS, EXDATE with timezones, leap years. Not API-dependent — computed locally.
expand_rrule({
rrule: "FREQ=WEEKLY;BYDAY=MO,WE,FR",
dtstart: "2026-02-01T09:00",
count: 10
})
// 10 exact occurrences, DST-safe ✓Availability Merging
Returns "these slots are free across all calendars" — not raw events for you to figure out. Google + Outlook + iCloud in one view.
get_availability({
calendars: ["google/primary",
"outlook/work", "caldav/personal"],
date: "2026-02-27"
})
// Merged free slots across all ✓How does Temporal Cortex work?
Install
npx @temporal-cortex/cortex-mcp
Authenticate
npx @temporal-cortex/cortex-mcp auth google
OAuth opens in your browser. One-time consent, credentials stored locally.
Your agent gets 11 tools across 4 layers
Temporal context, calendar operations, availability computation, and safe booking.
Agent schedules intelligently
get_temporal_context → resolve_datetime → find_free_slots → book_slot
10 seconds to first tool call. Full calendar access within 2 minutes.
How does Temporal Cortex compare?
| Feature | Temporal Cortex | nspady | rauf543 | MS Agent 365 |
|---|---|---|---|---|
| Atomic booking (2PC) | ✓ | ✗ | ✗ | ✗ |
| RRULE expansion | ✓ | ✗ | ✗ | ✗ |
| Multi-provider merge | ✓ | Partial | ✓ | ✗ |
| Availability computation | ✓ | ✗ | ✗ | ✗ |
| Open source | ✓ | ✓ | ✓ | ✗ |
| Temporal context (date/time math) | ✓ | ✗ | ✗ | ✗ |
Start free. Scale when you're ready.
Open source with no limits. Managed cloud for convenience. Pro for open scheduling.
Open Source
Free
Forever. No limits.
- ✓ All 11 tools
- ✓ No account required
- ✓ Your machine, your data
npx @temporal-cortex/cortex-mcpFree Cloud
$0
Account required
- ✓ 3 connected calendars
- ✓ 50 bookings/month
- ✓ Managed hosting
Pro
$29/mo
Open Scheduling
- ✓ Unlimited calendars
- ✓ 500 bookings/month
- ✓ Inbound booking + 2PC
The future is agent-to-agent scheduling
Today, AI agents use MCP tools to access calendars. Tomorrow, agents will negotiate scheduling with other agents directly. Temporal Cortex is building the infrastructure for this transition — from MCP tools to Agent Cards to the agentic web.
Today
The Tool Era
Agents use MCP tools to access calendars. You install a server and your agent gets 11 tools.
2027
The Agent Card Era
Each user gets an A2A-compliant scheduling agent. Agent Cards declare capabilities. Discovery via identity resolution.
2028+
The Agentic Web
Agent-to-agent scheduling in under 2 seconds, zero human intervention. Temporal Cortex becomes DNS for Human Time.
Give your AI agent a calendar that works
Install in 10 seconds. No account required. All 11 tools, immediately.
Questions? GitHub Issues are open.