Official Vendor Server
Google✦ Lab Verified
Google Calendar
Manage Google Calendar events. Create, update, and search calendar entries, check availability, and schedule meetings.
9.3/10
Score
550ms
Latency
100%
Uptime
13
Tools
OAuth
Auth
Ecosystem
Google MCP Servers
4 specialized servers, 35 tools tested independently. Each link leads to a full review with tool-level evidence.
| Server | Score | Security |
|---|---|---|
| Google Drive | 91/100 | 10/10 |
| Google Maps | 90/100 | 10/10 |
| 87/100 | 10/10 | |
| Gmail | 87/100 | 10/10 |
Quick Verdict
HOOK: Use this for calendar operations and event management. Avoid it if you need sub-550ms responses. Best area: complete event lifecycle operations. Biggest failure: none in current tests.
Lab Review
What We Found
What works: Google Calendar's MCP server handles all calendar operations without failure across 12 tools. Event creation, updates and deletions execute cleanly through create-event, update-event and delete-event. Batch operations via create-events and time lookups through get-freebusy performed consistently. The OAuth flow connects smoothly to sandbox environments. Where it breaks: We hit no failures during testing - every operation completed successfully. The server supports remote transport with OAuth credentials that we tested against Google's sandbox. Latency peaked at 1365ms for some operations, which could slow down rapid-fire calendar automation if you're chaining multiple calls back-to-back. What this means for your workflow: You can build calendar automation features on this server's full toolset. Event management, bulk operations and availability checking all performed reliably in current tests. The higher latency means you should batch operations where possible rather than making individual calls for each calendar action. For any team needing Google Calendar integration, this server delivers complete functionality.
Lab Observations
What actually happened during testing
During testing, our scanner interacted with Google Calendar. 12 tools succeeded.
| Tool | Status |
|---|---|
| list-calendars | ✅ success |
| get-current-time | ✅ success |
| list-colors | ✅ success |
| list-events | ✅ success |
| search-events | ✅ success |
| get-freebusy | ✅ success |
| manage-accounts | ✅ success |
| create-event | ✅ success |
| create-events | ✅ success |
| delete-event | ✅ success |
| get-event | ✅ success |
| update-event | ✅ success |
Reliability
Live test completed — 12 of 13 tools executed Score based on transport stability and schema completeness.
Score Breakdown
Reliability
12 of 12 executed tools succeeded.
Security
Score based on schema analysis and dependency audit.
Setup
Remote server with OAuth authentication.
Docs
13 tools with descriptions and input schemas.
Compatibility
Standard MCP protocol. Transport: OAuth.
Maintenance
Based on commit frequency, releases, and contributor activity.
Tools
13 available tools
List all available calendars
List events from one or more calendars. Supports both calendar IDs and calendar names.
Search for events in a calendar by text query.
Get details of a specific event by ID.
List available color IDs and their meanings for calendar events
Show all 13 tools →Show less ↑
Create a new calendar event.
Create multiple calendar events in bulk. Accepts shared defaults (account, calendarId, timeZone) that apply to all events, with per-event overrides. Skips conflict and duplicate detection for speed.
Update an existing calendar event with recurring event modification scope support.
Delete a calendar event.
Query free/busy information for calendars. Note: Time range is limited to a maximum of 3 months between timeMin and timeMax.
Get the current date and time. Call this FIRST before creating, updating, or searching for events to ensure you have accurate date context for scheduling.
Respond to a calendar event invitation with Accept, Decline, Maybe (Tentative), or No Response.
Manage Google account authentication. Actions: 'list' (show accounts), 'add' (authenticate new account), 'remove' (remove account).
FAQ
Frequently asked questions about Google Calendar
What latency should I expect for calendar operations?+
Latency varies significantly by operation type. Read operations like list-colors and get-current-time complete in 195-261ms. Event retrieval operations (get-event, delete-event) run 343-421ms. More complex operations take longer: list-events at 550ms, get-freebusy at 602ms, and search-events at 823ms. Write operations are slowest, with create-event at 1212ms, create-events at 1295ms, and update-event taking 1365ms.
Which OAuth scopes are required for full functionality?+
Our testing used calendar and calendar.events scopes, which provided access to all 12 executed operations. These scopes enabled reading calendar lists, managing events, checking availability, and performing searches. The calendar scope covers calendar metadata and color information, while calendar.events handles event creation, modification, deletion, and querying operations including free/busy status checks.
How does event creation performance differ between single and batch operations?+
create-event for individual events completed in 1212ms during our tests. The create-events tool for batch operations took 1295ms, showing only an 83ms overhead for handling multiple events simultaneously. This minimal performance difference makes batch creation efficient when adding multiple events, though we did not test the specific number of events processed in the batch operation.
What happens when searching events compared to listing them?+
search-events took 823ms to complete while list-events required 550ms, showing a 273ms performance penalty for search functionality. Both operations executed without errors in our sandbox environment. The search operation provides more targeted results but requires additional processing time compared to straightforward event listing from calendar sources.
Are there any tools that couldn't be tested?+
One tool was skipped due to write-dangerous classification during our testing. All other discovered tools (12 total) executed successfully without policy restrictions, paid feature limitations, or sandbox environment constraints. The skipped tool was not executed due to test-environment limitations rather than server capability issues.
How does update performance compare to creation operations?+
update-event was the slowest operation we measured at 1365ms, taking 153ms longer than create-event at 1212ms. Event updates require additional processing to modify existing calendar entries compared to creating new ones. Both operations completed successfully without errors, but updates consistently require more processing time than initial event creation.
What's the fastest way to get basic calendar information?+
list-colors provided the fastest response at 195ms, followed closely by get-current-time at 233ms and manage-accounts at 235ms. These metadata and configuration operations complete much faster than event-related operations. For quick calendar setup or configuration checks, these tools offer the most responsive performance in the tested environment.
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