Comparison
How does Temporal Cortex compare to other Calendar MCP servers?
Most Calendar MCP servers are thin CRUD wrappers — they create, read, update, and delete events, but they lack scheduling safety. Temporal Cortex is the only Calendar MCP server with atomic booking (Two-Phase Commit), deterministic RRULE expansion (Truth Engine), cross-provider availability merging, and temporal context tools. Here is how it compares to every major alternative.
Feature comparison
12 features across 6 Calendar MCP servers. Green checkmarks indicate full support, yellow indicates partial support, and red indicates no support.
| Feature | Temporal Cortex | nspady | rauf543 | MS Agent 365 | taylorwilsdon | Nylas / Cronofy |
|---|---|---|---|---|---|---|
| Atomic booking (2PC) | ✓ | ✗ | ✗ | ✗ | ✗ | ✗ |
| RRULE expansion | ✓ | ✗ | ✗ | ✗ | ✗ | ✗ |
| Multi-provider merge | ✓ | ✗ | ✓ | ✗ | ✗ | Partial |
| Availability computation | ✓ | Partial | ✗ | ✗ | ✗ | ✗ |
| Temporal context (date/time math) | ✓ | ✗ | ✗ | ✗ | ✗ | ✗ |
| Conflict detection | ✓ | Partial | ✗ | ✗ | ✗ | Partial |
| Open source | ✓ | ✓ | ✓ | ✗ | ✓ | ✗ |
| Agent Skill | ✓ | ✗ | ✗ | ✗ | ✗ | ✗ |
| Truth Engine (deterministic RRULE) | ✓ | ✗ | ✗ | ✗ | ✗ | ✗ |
| CalDAV support | ✓ | ✗ | ✓ | ✗ | ✗ | Partial |
| MCP native | ✓ | ✓ | ✓ | ✗ | ✓ | ✗ |
| Self-hostable | ✓ | ✓ | ✓ | ✗ | ✓ | ✗ |
How Temporal Cortex differs from each alternative
Each Calendar MCP server has different strengths. Here is a breakdown of what each one does and where Temporal Cortex provides additional capabilities.
nspady/google-calendar-mcp
Google Calendar only, multi-accountA popular Google Calendar MCP server with 12 tools including free/busy queries, multi-account support, and cross-account conflict detection. Single-provider (Google only) — no cross-provider availability merging or atomic booking.
rauf543/calendar-mcp
Multi-provider: Google, Outlook, CalDAVA multi-provider Calendar MCP server supporting Google Calendar, Microsoft Outlook, and CalDAV. Provides basic CRUD operations across providers but lacks availability computation, RRULE expansion, and atomic booking.
MS Agent 365
Preview, Outlook only, not open sourceMicrosoft's agent framework for Outlook and Microsoft 365 calendars. Currently in preview, Outlook-only, and not open source. Tightly integrated with the Microsoft ecosystem but limited to a single provider.
taylorwilsdon/google_workspace_mcp
~1.6k GitHub stars, Google Workspace scopeA Google Workspace MCP server (~1.6k stars) that covers Google Calendar, Drive, Gmail, and other Workspace APIs. Broader than calendar-only but lacks scheduling-specific features like availability computation and atomic booking.
Nylas / Cronofy
Scheduling APIs, experimental MCP wrappersEnterprise scheduling APIs with experimental MCP wrappers. Nylas and Cronofy are established scheduling platforms, but their MCP integrations are not calendar-native — they wrap existing REST APIs rather than providing purpose-built MCP tools.
Why choose Temporal Cortex?
Temporal Cortex is the only Calendar MCP server that combines all three scheduling safety primitives: atomic booking, deterministic recurrence, and cross-provider availability. No other MCP server has all three.
Atomic Booking (2PC)
Lock → verify → write → release. If any step fails, everything rolls back. Zero double-bookings, even with concurrent agents. No other Calendar MCP server has distributed locking.
Truth Engine
Deterministic RRULE expansion written in Rust. Handles DST transitions, BYSETPOS, EXDATE with timezones, and leap years. Not API-dependent — computed locally with zero hallucination.
Availability Merging
Returns "these slots are free across all calendars" — not raw events. Google Calendar + Outlook + iCloud merged into a single availability view. Other servers require the LLM to compute this.
Frequently asked questions
What is the best calendar MCP server?
Temporal Cortex is the most feature-complete Calendar MCP server available. It is the only one with atomic booking via Two-Phase Commit, deterministic RRULE expansion via the Truth Engine, cross-provider availability merging (Google Calendar + Outlook + CalDAV), temporal context tools for date/time math, and an Agent Skill for procedural scheduling knowledge. Other Calendar MCP servers provide basic CRUD operations but lack scheduling safety and availability computation.
How does Temporal Cortex compare to Google Calendar MCP?
Google Calendar MCP servers like nspady/google-calendar-mcp provide 12 tools for Google Calendar including free/busy queries and multi-account support. Temporal Cortex differentiates with cross-provider availability merging (Google + Outlook + CalDAV in a single view), deterministic RRULE expansion via Truth Engine, temporal context tools (date/time resolution, timezone conversion), and atomic booking with Two-Phase Commit and distributed locking. The key distinction: nspady queries availability within Google accounts, while Temporal Cortex merges availability across providers and prevents double-bookings with locking.
Is Temporal Cortex better than Nylas for AI agents?
Nylas and Cronofy are established scheduling APIs designed for traditional application integrations. Their MCP wrappers are experimental and not calendar-native — they wrap existing REST APIs rather than providing purpose-built MCP tools. Temporal Cortex is built MCP-native from the ground up with 12 tools specifically designed for AI agent workflows, including temporal context, deterministic RRULE expansion, cross-provider availability merging, and atomic booking. For AI agents using the Model Context Protocol, Temporal Cortex provides a more complete and reliable scheduling experience.
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