Calendar Scheduling & Booking

14 tools (Layers 0, 2–4) for contact resolution, calendar discovery, event querying, free slot finding, availability checking, RRULE expansion, atomic booking, Open Scheduling, and proposal composition. 12 read-only tools + 2 write tools (book_slot, request_booking).

Source & Provenance

• - Homepage: temporal-cortex.com
• Source code: github.com/temporal-cortex/mcp (open-source Rust)
• npm package: @temporal-cortex/cortex-mcp
• Skills repo: github.com/temporal-cortex/skills

Runtime

These tools run inside the Temporal Cortex MCP server (@temporal-cortex/cortex-mcp), a compiled Rust binary distributed as an npm package.

Install and startup lifecycle:

1. 1. npx resolves @temporal-cortex/cortex-mcp from the npm registry (one-time, cached locally after first download)
2. The postinstall script downloads the platform-specific binary from the GitHub Release and verifies its SHA256 checksum against the embedded checksums.json — installation halts on mismatch
3. The MCP server starts as a local process communicating over stdio (no listening ports)
4. Calendar tools make authenticated API calls to your configured providers (Google Calendar API, Microsoft Graph API, CalDAV endpoints)

Credential storage: OAuth tokens are stored locally at ~/.config/temporal-cortex/credentials.json and read exclusively by the local MCP server process. No credential data is transmitted to Temporal Cortex servers. The binary's filesystem access is limited to ~/.config/temporal-cortex/ — verifiable by inspecting the open-source Rust code or running under Docker where the mount is the only writable path.

File access: The binary reads and writes only ~/.config/temporal-cortex/ (credentials and config). No other filesystem writes.

Network scope: Calendar tools connect only to your configured providers (googleapis.com, graph.microsoft.com, or your CalDAV server). In Local Mode (default), no calls to Temporal Cortex servers and no telemetry is collected. In Platform Mode, three tools (resolve_identity, query_public_availability, request_booking) call api.temporal-cortex.com for cross-user scheduling — no credential data is included in these calls.

Pre-run verification (recommended before first use):

1. 1. Inspect the npm package without executing: INLINECODE15
2. Verify checksums independently against the GitHub Release (see verification pipeline below)
3. For full containment, run in Docker instead of npx (see Docker containment below)

Verification pipeline: Checksums are published independently at each GitHub Release as SHA256SUMS.txt — verify the binary before first use:

CODEBLOCK0

As defense-in-depth, the npm package also embeds checksums.json and the postinstall script compares SHA256 hashes during install — installation halts on mismatch (the binary is deleted, not executed). This automated check supplements, but does not replace, independent verification above.

Build provenance: Binaries are cross-compiled from auditable Rust source in GitHub Actions across 5 platforms (darwin-arm64, darwin-x64, linux-x64, linux-arm64, win32-x64). Source: github.com/temporal-cortex/mcp (MIT-licensed). The CI workflow, build artifacts, and release checksums are all publicly inspectable.

Docker containment (no Node.js on host, credential isolation via volume mount):

CODEBLOCK1

Build: INLINECODE18

Tools

Layer 0 — Discovery

Tool	When to Use
INLINECODE19	DNS for Human Time: resolve an email, phone, or agent ID to a Temporal Cortex slug. Call before query_public_availability. Platform Mode only.
INLINECODE21

Search the user's address book by name (Google People API, Microsoft Graph). Returns matching contacts with emails, phones, organization, and job title. Opt-in — requires contacts permission. | | resolve_contact | Given a confirmed contact's email, determine the best scheduling path: Open Scheduling (instant booking), email, or phone. Chains with resolve_identity when Platform API is available. |

Layer 2 — Calendar Operations

Tool	When to Use
INLINECODE24	First call when calendars are unknown. Returns all connected calendars with provider-prefixed IDs, names, labels, primary status, and access roles.
INLINECODE25

List events in a time range. TOON format by default (~40% fewer tokens than JSON). Use provider-prefixed IDs for multi-calendar: "google/primary", "outlook/work". | | find_free_slots | Find available gaps in a calendar. Set min_duration_minutes for minimum slot length. | | expand_rrule | Expand recurrence rules (RFC 5545) into concrete instances. Handles DST, BYSETPOS, EXDATE, leap years. Use dtstart as local datetime (no timezone suffix). | | check_availability | Check if a specific time slot is free. Checks both events and active booking locks. |

Layer 3 — Availability

Tool	When to Use
INLINECODE33	Merged free/busy view across multiple calendars. Pass calendar_ids array. Privacy: "opaque" (default, hides sources) or "full".
INLINECODE37

Check another user's public availability by Temporal Link slug. Pass the slug and date to find their open time slots. Platform Mode only. |

Layer 4 — Booking

Tool	When to Use
INLINECODE38	Book a time slot atomically. Lock → verify → write → release. Always check_availability first.
INLINECODE40

Book on another user's public calendar by Temporal Link slug. Requires Platform Mode. | | compose_proposal | Compose a scheduling proposal message for email, Slack, or SMS. Formats proposed times in the recipient's timezone with an optional Temporal Link self-serve booking URL. Does NOT send — returns formatted text for the agent to send via its channel MCP. |

Critical Rules

1. 1. Discover calendars first — call list_calendars when you don't know which calendars are connected. Use the returned provider-prefixed IDs for all subsequent calls.
2. Use provider-prefixed IDs for multi-calendar setups: "google/primary", "outlook/work", "caldav/personal". Bare IDs (e.g., "primary") route to the default provider.
3. TOON is the default format — output uses TOON (~40% fewer tokens than JSON). Pass format: "json" only if you need structured parsing.
4. Check before booking — always call check_availability before book_slot. Never skip the conflict check.
5. Content safety — event summaries and descriptions pass through a sanitization firewall before reaching the calendar API.
6. Timezone awareness — all tools accept RFC 3339 with timezone offsets. Never use bare dates.
7. Confirm before booking — when running autonomously, always present booking details (time, calendar, summary) to the user and wait for confirmation before calling book_slot or request_booking.
8. Confirm contact selection — when search_contacts returns multiple matches, present candidates to the user and confirm which contact is correct. Never auto-select.
9. Confirm before sending proposals — when using compose_proposal, present the composed message to the user before sending. Never auto-send outreach.
10. Contact search is optional — if contacts permission is not configured, ask the user for the email directly. The workflow works without contact search.

Full Booking Workflow

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If the slot is busy at step 5, use find_free_slots to suggest alternatives.

Open Scheduling Workflow (Platform Mode)

CODEBLOCK3

Two-Phase Commit Protocol

CODEBLOCK4

If any step fails, the lock is released and the booking is aborted. No partial writes.

Common Patterns

Schedule with a Contact (End-to-End)

CODEBLOCK5

List Events This Week

CODEBLOCK6

Find Free Time Across Calendars

CODEBLOCK7

Check and Book a Slot

CODEBLOCK8

Expand Recurring Events

CODEBLOCK9

Provider-Prefixed Calendar IDs

All calendar IDs use provider-prefixed format:

Format	Example	Routes to
INLINECODE55	INLINECODE56	Google Calendar
INLINECODE57

"outlook/work" | Microsoft Outlook |
| caldav/<id> | "caldav/personal" | CalDAV (iCloud, Fastmail) |
| <id> (bare) | "primary" | Default provider |

Privacy Modes

Mode	INLINECODE63	Use case
INLINECODE64 (default)	Always INLINECODE65	Sharing availability externally
INLINECODE66

Actual count | Internal use — shows which calendars are busy |

Tool Annotations (book_slot)

Property	Value	Meaning
INLINECODE68	INLINECODE69	Creates calendar events
INLINECODE70

false | Never deletes or overwrites existing events | | idempotentHint | false | Calling twice creates two events | | openWorldHint | true | Makes external API calls |

Tool Annotations (request_booking)

Property	Value	Meaning
INLINECODE77	INLINECODE78	Creates calendar events on another user's calendar
INLINECODE79

false | Never deletes or overwrites existing events | | idempotentHint | false | Calling twice creates two bookings | | openWorldHint | true | Calls the Platform API |

Tool Annotations (compose_proposal)

Property	Value	Meaning
INLINECODE86	INLINECODE87	Pure formatting — no state modification
INLINECODE88

false | Never deletes data | | idempotentHint | true | Same input always gives same output | | openWorldHint | false | No external calls — pure computation |

Tool Annotations (search_contacts)

Property	Value	Meaning
INLINECODE95	INLINECODE96	Reads contacts only — no modifications
INLINECODE97

false | Never deletes contacts | | idempotentHint | true | Same query always gives same results | | openWorldHint | true | Calls external contact API (Google People / Microsoft Graph) |

Error Handling

Error	Action
"No credentials found"	Run: npx @temporal-cortex/cortex-mcp auth google (or outlook / caldav).
"Timezone not configured"

Prompt for IANA timezone. Or run the auth command which configures timezone. | | Slot is busy / conflict detected | Use find_free_slots to suggest alternatives. Present options to user. | | Lock acquisition failed | Another agent is booking the same slot. Wait briefly and retry, or suggest alternative times. | | Content rejected by sanitization | Rephrase the event summary/description. The firewall blocks prompt injection attempts. |

Open Scheduling & Temporal Links

When a user has Open Scheduling enabled, their Temporal Link (book.temporal-cortex.com/{slug}) allows anyone to:

1. 1. Query availability — INLINECODE108
2. Book a meeting — POST /public/{slug}/book with INLINECODE110
3. Discover via Agent Card — INLINECODE111

Workflow: Book via Temporal Link

1. 1. User shares their Temporal Link
2. Agent calls availability endpoint to find free slots
3. Agent calls booking endpoint with selected slot
4. Meeting is created on the user's default calendar

See Temporal Links Reference for detailed API documentation.

Additional References

• - Calendar Tools Reference — Complete input/output schemas for all 14 tools
• Multi-Calendar Guide — Provider routing, labels, privacy modes, cross-provider operations
• RRULE Guide — Recurrence rule patterns, DST edge cases, 5 LLM failure modes
• Booking Safety — 2PC details, concurrent booking, lock TTL, content sanitization
• Temporal Links — Open Scheduling endpoints, Agent Card integration, calendar routing
• Open Scheduling Guide — Identity resolution, public availability, external booking via MCP tools