io.github.deciduus/calendar-mcp
PYPI · CALENDAR-MCP-SERVER · SCANNED SEP 20
Google Calendar for LLM agents: find, create, update, move, delete events; free/busy; scheduling.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →
Supply Chain Security100
- No malware found by supply-chain analysis.Pass
- No known CVEs affecting this package version or its production dependencies.Pass
- Runs setuptools.build_meta at install time, a recognised native-build step with no shell scripting around it. View diagnostics → Pass
- 3 of 55 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency32
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Provenance check failed: no build-provenance attestation is published. See how to fix → View diagnostics → Fail
- License check failed: no license is declared. See how to fix → Fail
- Actively maintained (last published 14 days ago).Pass
- Disclosure check failed: no security disclosure policy was found in the source repository. See how to fix → Fail
Schema Quality & AI Usability70
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 2621 tokens (~174/item across 15 items; 15 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management50
- Stability observed for 15 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage71
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 0% of tool parameters carry a description.Fail
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- All 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 16 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
How do I install the io.github.deciduus/calendar-mcp server?
io.github.deciduus/calendar-mcp runs locally as a PyPI package, launched with uvx calendar-mcp-server. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
pypi · calendar-mcp-server
claude mcp add deciduus-calendar-mcp -- uvx calendar-mcp-server
{
"mcpServers": {
"deciduus-calendar-mcp": {
"command": "uvx",
"args": [
"calendar-mcp-server"
]
}
}
} {
"servers": {
"deciduus-calendar-mcp": {
"command": "uvx",
"args": [
"calendar-mcp-server"
]
}
}
} codex mcp add deciduus-calendar-mcp -- uvx calendar-mcp-server
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"deciduus-calendar-mcp": {
"type": "local",
"command": [
"uvx",
"calendar-mcp-server"
],
"enabled": true
}
}
} openclaw mcp add deciduus-calendar-mcp --command uvx --arg calendar-mcp-server
mcp_servers:
deciduus-calendar-mcp:
command: "uvx"
args: ["calendar-mcp-server"] {
"McpServers": {
"deciduus-calendar-mcp": {
"Transport": "stdio",
"Command": "uvx",
"Arguments": [
"calendar-mcp-server"
]
}
}
} assistant mcp add deciduus-calendar-mcp -t stdio -c uvx -a calendar-mcp-server
{
"mcpServers": {
"deciduus-calendar-mcp": {
"command": "uvx",
"args": [
"calendar-mcp-server"
]
}
}
} Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 20 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 47 to 50. That category is still filling its 30-day observation window: 14 days of observed history at the previous scan, 15 at this one. The score rises as the window fills, whether or not the server changes.
- 18 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 40 to 43. That category is still filling its 30-day observation window: 12 days of observed history at the previous scan, 13 at this one. The score rises as the window fills, whether or not the server changes.
- 16 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.
- 14 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.
- 13 Sept 26 +3
- Stability: unverified → 0.27 ▲ functional
- 6 Sept 26 +15
- Malware scan: unverified → pass ▲ security
- 5 Sept 26 50
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 20 Sept 2026 · Analysed pypi/calendar-mcp-server@1.0.1
Provenance No attestation
The registry publishes no build provenance for this version, so there is nothing to verify.
| Result | No attestation |
|---|---|
| Ecosystem | pypi |
Background: How many MCP packages publish verified provenance →
Install scripts 1 script
| Hook | Tier | Command |
|---|---|---|
| build_backend | allowlisted | setuptools.build_meta |
Background: Why install scripts are a supply-chain risk →
Dependencies 55 packages
| Packages resolved | 55 |
|---|---|
| Stale | 2 |
| No linked repository | 1 |
| Tree resolution | Complete |
Background: SBOMs and build attestations, explained →
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
add_attendee Add attendees ~115
Invite one or more people to an existing event. Existing attendees are kept; the new addresses are appended. Args: event_id: The event to invite people to (from `find_events`). attendee_emails: Email addresses to invite. calendar_id: Calendar the event lives on. send_notifications: Whether Google emails the attendees. Default true.
| Name | Type | Req | Description |
|---|---|---|---|
| attendee_emails | array | yes | – |
| calendar_id | string | – | – |
| event_id | string | yes | – |
| send_notifications | boolean | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar the event lives on. |
| event | – | yes | The event after the operation. |
| message | string | – | One-line human-readable summary of what happened. |
No examples provided.
analyze_busyness Analyze calendar load ~103
Summarise how loaded each day is: event count and total scheduled minutes. Use this to answer "how busy is my week" without listing every event. Args: time_min: Start of the window, ISO 8601. time_max: End of the window, ISO 8601. calendar_id: Calendar to analyse.
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | – | – |
| time_max | string | yes | – |
| time_min | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar that was analysed. |
| days | array | – | Per-day totals, in date order. |
| time_max | string | yes | End of the analysed window, ISO 8601. |
| time_min | string | yes | Start of the analysed window, ISO 8601. |
| total_duration_minutes | number | – | Sum of total_duration_minutes across all days. |
| total_events | integer | – | Sum of event_count across all days. |
No examples provided.
check_attendee_status Check attendee RSVPs ~92
Report who has accepted, declined or not yet answered an event invitation. Args: event_id: The event to inspect (from `find_events`). calendar_id: Calendar the event lives on. attendee_emails: Restrict the report to these addresses. Omit for all.
| Name | Type | Req | Description |
|---|---|---|---|
| attendee_emails | – | – | – |
| calendar_id | string | – | – |
| event_id | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| attendees | array | – | Attendees and their current RSVP state. |
| calendar_id | string | yes | Calendar the event lives on. |
| count | integer | yes | Number of attendees reported. |
| event_id | string | yes | Event that was checked. |
No examples provided.
create_calendar Create a calendar ~43
Create a new secondary calendar owned by the user. Args: summary: Name for the new calendar, e.g. 'Client work'.
| Name | Type | Req | Description |
|---|---|---|---|
| summary | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| access_role | – | – | The user's role: 'owner', 'writer', 'reader', 'freeBusyReader'. |
| description | – | – | Calendar description. |
| id | string | yes | Calendar ID. Pass this as calendar_id to other tools. |
| primary | boolean | – | True for the user's main calendar (also addressable as 'primary'). |
| summary | – | – | Calendar name. |
| time_zone | – | – | IANA timezone of the calendar, e.g. 'Europe/Berlin'. |
No examples provided.
create_event Create an event ~243
Create an event with explicit start and end times, and optional attendees. For a one-line natural-language description ("coffee with Sam tomorrow at 3") prefer `quick_add_event`. Args: calendar_id: Calendar to create the event on. summary: Event title. Required. start_time: Start, ISO 8601 with a UTC offset (e.g. '2026-03-14T15:00:00-04:00'). Without an offset it is read in the calendar's own timezone. end_time: End, ISO 8601, same convention as start_time. description: Longer notes for the event body. location: Free-text location or meeting link. attendee_emails: People to invite. They receive an invitation email unless send_notifications is false. send_notifications: Whether Google emails the attendees. Default true.
| Name | Type | Req | Description |
|---|---|---|---|
| attendee_emails | – | – | – |
| calendar_id | string | – | – |
| description | – | – | – |
| end_time | string | – | – |
| location | – | – | – |
| send_notifications | boolean | – | – |
| start_time | string | – | – |
| summary | string | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar the event lives on. |
| event | – | yes | The event after the operation. |
| message | string | – | One-line human-readable summary of what happened. |
No examples provided.
delete_event Delete an event ~118
Permanently delete an event. This cannot be undone. Clients that support elicitation are asked to confirm first; if the user declines, nothing is deleted and `deleted` comes back false. Args: event_id: The event to delete (from `find_events`). calendar_id: Calendar the event lives on. send_notifications: Whether Google emails the attendees that it was cancelled. Default true.
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | – | – |
| event_id | string | yes | – |
| send_notifications | boolean | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar the event was on. |
| confirmed_by_user | – | – | True/False when the client answered a confirmation prompt; null when the client does not support elicitation. |
| deleted | boolean | yes | True when the event was removed. |
| event_id | string | yes | ID of the deleted event. |
| message | string | – | One-line human-readable summary of what happened. |
No examples provided.
find_events Find events ~181
Search a calendar for events, expanding recurring series into instances. Use this before any tool that needs an `event_id`. Narrow the window with `time_min`/`time_max` rather than raising `max_results`. Args: calendar_id: Calendar to search. 'primary' is the user's own calendar. time_min: Inclusive start of the window, ISO 8601 with a UTC offset. Without an offset it is read in the calendar's own timezone. time_max: Exclusive end of the window, ISO 8601. query: Free-text search over title, description, location and attendees. max_results: Maximum events to return (default 50).
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | – | – |
| max_results | integer | – | – |
| query | – | – | – |
| time_max | – | – | – |
| time_min | – | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar that was searched. |
| count | integer | yes | Number of events returned. |
| events | array | – | The matching events, earliest first. |
| time_zone | – | – | IANA timezone of the calendar that was searched. |
No examples provided.
list_calendars List calendars ~107
List the calendars the signed-in user can see, with their IDs and timezones. Start here whenever the user mentions a calendar other than their own: the `id` values returned are what every other tool's `calendar_id` expects. Args: min_access_role: Only return calendars where the user has at least this role: 'freeBusyReader', 'reader', 'writer' or 'owner'. Omit for all.
| Name | Type | Req | Description |
|---|---|---|---|
| min_access_role | – | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendars | array | – | The user's calendars. |
| count | integer | yes | Number of calendars returned. |
No examples provided.
move_event Move or reschedule an event ~203
Reschedule an event, and/or move it to a different calendar. Supplying only `new_start` keeps the event's original duration -- this is the right tool for "push my 2pm back an hour". Supplying `destination_calendar_id` transfers the event between calendars. Args: event_id: The event to move (from `find_events`). calendar_id: Calendar the event currently lives on. new_start: New start, ISO 8601. Duration is preserved if new_end is omitted. new_end: New end, ISO 8601. Optional when new_start is given. destination_calendar_id: Calendar to transfer the event to. send_notifications: Whether Google emails the attendees. Default true.
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | – | – |
| destination_calendar_id | – | – | – |
| event_id | string | yes | – |
| new_end | – | – | – |
| new_start | – | – | – |
| send_notifications | boolean | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar the event lives on. |
| event | – | yes | The event after the operation. |
| message | string | – | One-line human-readable summary of what happened. |
No examples provided.
project_recurring_events Project recurring events ~155
Compute future occurrences of recurring events from their recurrence rules. Unlike `find_events`, this expands the RRULEs locally, so it reaches past the horizon Google materialises instances for -- useful for "when do my birthdays / standups land next year". Args: time_min: Start of the projection window, ISO 8601. time_max: End of the projection window, ISO 8601. calendar_id: Calendar whose recurring events should be projected. event_query: Only project recurring events matching this text, e.g. 'Birthday'.
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | – | – |
| event_query | – | – | – |
| time_max | string | yes | – |
| time_min | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar that was projected. |
| count | integer | yes | Number of projected occurrences. |
| occurrences | array | – | Computed occurrences, earliest first. |
| time_max | string | yes | End of the projection window, ISO 8601. |
| time_min | string | yes | Start of the projection window, ISO 8601. |
No examples provided.
query_free_busy Query free/busy ~122
Get busy intervals for one or more calendars, without revealing event details. Works for other people's calendars addressed by email, which is how you check whether someone is free before proposing a time. Args: calendar_ids: Calendar IDs or attendee email addresses to check. time_min: Start of the window, ISO 8601 with a UTC offset. time_max: End of the window, ISO 8601 with a UTC offset.
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_ids | array | yes | – |
| time_max | string | yes | – |
| time_min | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendars | array | – | Per-calendar busy intervals. |
| time_max | string | yes | End of the queried window, ISO 8601. |
| time_min | string | yes | Start of the queried window, ISO 8601. |
No examples provided.
quick_add_event Quick-add an event ~129
Create an event from a plain-English phrase, parsed by Google. Google interprets the date, time and title itself, in the calendar's own timezone. Check the returned start/end and tell the user what was booked -- the parser guesses, and does not handle attendees or descriptions. Args: text: The phrase to parse, e.g. 'Dentist Thursday 9am' or 'Team sync every Monday at 10 for 30 minutes'. calendar_id: Calendar to create the event on.
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | – | – |
| text | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar the event lives on. |
| event | – | yes | The event after the operation. |
| message | string | – | One-line human-readable summary of what happened. |
No examples provided.
respond_to_event RSVP to an event ~152
Set the user's own RSVP on an invitation they have received. Only works on events the user is an attendee of; it does not change anyone else's response. Args: event_id: The invitation to answer (from `find_events`). response_status: 'accepted', 'declined', 'tentative' or 'needsAction'. calendar_id: Calendar the invitation lives on. comment: Optional note sent to the organizer with the RSVP. send_notifications: Whether Google emails the organizer. Default true.
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | – | – |
| comment | – | – | – |
| event_id | string | yes | – |
| response_status | string | yes | – |
| send_notifications | boolean | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar the event lives on. |
| event | – | yes | The event after the operation. |
| message | string | – | One-line human-readable summary of what happened. |
No examples provided.
schedule_mutual Find a mutual slot and schedule ~327
Find the first slot where everyone is free, then book the meeting there. Reads each attendee's free/busy inside the window, picks the earliest gap that fits `duration_minutes`, and creates the event with all of them invited. Fails with an error if no common slot exists -- widen the window or shorten the meeting and try again. Args: attendee_calendar_ids: Attendee email addresses whose availability matters. time_min: Earliest the meeting may start, ISO 8601 with a UTC offset. time_max: Latest the meeting may end, ISO 8601 with a UTC offset. duration_minutes: Length of the meeting in minutes. summary: Title for the meeting. description: Optional agenda or notes. location: Optional location or meeting link. organizer_calendar_id: Calendar the meeting is created on. working_hours_start: Optional daily earliest start, 'HH:MM' local to the calendar, e.g. '09:00'. working_hours_end: Optional daily latest end, 'HH:MM', e.g. '17:00'. send_notifications: Whether Google emails the attendees. Default true.
| Name | Type | Req | Description |
|---|---|---|---|
| attendee_calendar_ids | array | yes | – |
| description | – | – | – |
| duration_minutes | integer | yes | – |
| location | – | – | – |
| organizer_calendar_id | string | – | – |
| send_notifications | boolean | – | – |
| summary | string | yes | – |
| time_max | string | yes | – |
| time_min | string | yes | – |
| working_hours_end | – | – | – |
| working_hours_start | – | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar the event lives on. |
| event | – | yes | The event after the operation. |
| message | string | – | One-line human-readable summary of what happened. |
No examples provided.
update_event Update an event ~187
Change fields on an existing event. Omitted fields are left untouched. To reschedule while keeping the duration, use `move_event` instead: changing only `start_time` here leaves the old end time in place. Args: calendar_id: Calendar the event lives on. event_id: The event to update (from `find_events`). Required. summary: New title. start_time: New start, ISO 8601. end_time: New end, ISO 8601. description: New description. location: New location. send_notifications: Whether Google emails the attendees. Default true.
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | – | – |
| description | – | – | – |
| end_time | – | – | – |
| event_id | string | – | – |
| location | – | – | – |
| send_notifications | boolean | – | – |
| start_time | – | – | – |
| summary | – | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| calendar_id | string | yes | Calendar the event lives on. |
| event | – | yes | The event after the operation. |
| message | string | – | One-line human-readable summary of what happened. |
No examples provided.
What is the io.github.deciduus/calendar-mcp server?
io.github.deciduus/calendar-mcp is listed in the public MCP registry as io.github.deciduus/calendar-mcp. Google Calendar for LLM agents: find, create, update, move, delete events; free/busy; scheduling. This page covers its PyPI package (calendar-mcp-server).
Is the io.github.deciduus/calendar-mcp server safe to use?
io.github.deciduus/calendar-mcp scores 72 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 20 September 2026. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the io.github.deciduus/calendar-mcp server expose?
io.github.deciduus/calendar-mcp exposes 15 tools: list_calendars, create_calendar, find_events, check_attendee_status, query_free_busy, and 10 more. Their descriptions and schemas cost roughly 2,277 tokens of context every time the server is loaded.
Is the io.github.deciduus/calendar-mcp server still maintained?
io.github.deciduus/calendar-mcp is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.