CalDAV calendars MCP server

by ni-c·io.github.ni-c/caldav-mcp·v0.1.5

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Read and write CalDAV calendars: events, tasks and journal entries over the open standard

B83/100grade B

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Safety scan

B83/100

full report

Adoption

Growing

0 stars74 downloads/wk

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CalDAV calendars tools (22, 9 write)

write = sends, deletes, buys or posts

Read from the package source without running it. The installed server may list more.

complete_task
Sets the task’s status. Marking it done records the completion time
create_eventwrite action
Adds an event to a calendar. The UID and the file name are generated
create_journalwrite action
Adds a dated note to a calendar that accepts journal entries.
create_taskwrite action
Adds a task to a calendar that accepts them. list_calendars reports
delete_eventwrite action
Removes an event. An occurrence id removes just that occurrence —
delete_journalwrite action
Removes a dated note. A CalDAV server keeps no history, and a note is
delete_taskwrite action
Removes a task. A CalDAV server keeps no history: this cannot be
get_event
The complete event behind an id from a listing: the untruncated
get_free_busy
Busy periods in a time range — start and end only, no titles and no
get_journal
The complete note behind an id from list_journals, untruncated. This
get_server_info
Reports the DAV compliance tokens, which components each calendar
get_task
The complete task behind an id from list_tasks, with its untruncated
list_calendars
Every calendar this server may use, with the id to pass to the other
list_events
Events between two points in time, from every calendar this server
list_journals
Dated notes in a calendar, inside a time range. Most calendar
list_tasks
Tasks with a start or due date inside a time range. Tasks with no
move_event
Copies an event into another calendar and removes it from the first.
respond_to_event
Sets your own participation status on an event you were invited to.
search_events
Finds events whose summary, description or location contains a term.
update_eventwrite action
Changes the fields named and leaves everything else exactly as it
update_journalwrite action
Replaces the fields named. A CalDAV server keeps no version history,
update_taskwrite action
Changes the fields named and leaves everything else as it was. Pass

Public scan report

scanner v0.1.10 · 2026-10-15 · same rubric, same numbers if you re-run it

no findings

Code scan57 source files scanned25/25
–Live reliabilityno gateway calls yet and no remote to proben/a
–Tool poisoningtools not inspected (local package is not executed); not countedn/a
Auth qualitystatic API keys via environment variables6/15
Maintenancelast push 2 days ago15/15
Maintainer identityregistry namespace matches repository owner; GitHub account older than a year8/10

Overall 83/100. Components that don't apply are left out of the denominator. Any critical finding is an F.Rubric Appeal a finding JSON

How CalDAV calendars compares

Against every graded MCP server, from our own scans and uptime checks. Updated after each scan run.

Safety score: 83/100; higher than 65% of 48,255 servers
Tools: 22; the typical server has 7
Tools that change things: 41%; typical: 0%. Fewer write tools means less an agent can break
Downloads a week: 74; more than 55% of 12,191 servers with a package

What its tools let an agent do: 12 read · 3 create · 4 change · 3 delete

Release history: 2 versions in the registry since 2026-09-08, latest 2026-10-13, typically one every 35 days.

Install CalDAV calendars in Claude Code, Cursor or VS Code

Runs npx -y @ni-c/caldav-mcp on your machine. Read the scan report first; the gateway never runs local packages.

claude mcp add caldav-mcp -- npx -y @ni-c/caldav-mcp

Add to Cursor

What the publisher says

From the CalDAV calendars repository's README, as published. We do not edit it. Read it on GitHub

caldav-mcp

A Model Context Protocol (MCP) server for CalDAV, the open calendar standard behind Nextcloud, Radicale, Baikal, SOGo, Fastmail, mailbox.org and iCloud.

Lets MCP clients like Claude Code, Claude Desktop or Codex work with your calendar: see what is on, find a free slot, create and change events, keep tasks and dated notes, and answer an invitation — against your own server, with no vendor API in between.

Twenty-two tools is the ceiling, not the floor: CALDAVALLOWTOOLS=essential registers a curated seven instead, and a model picks the right tool far more reliably from seven than from twenty-two — see choosing which tools load.

What makes it different

Recurring entries are expanded here, not asked of the server. A weekly meeting is stored as one rule plus a handful of exceptions; this server turns that into individual occurrences, each with an id of its own, so one of them can be moved without touching the rest. RFC 4791 does offer server-side expansion — but support for it is uneven and its absence is silent: a server that ignores the request answers with the master component, so the result looks thin rather than wrong. Doing it here behaves the same everywhere, and it means a 09:00 meeting stays at 09:00 across a daylight-saving change.

Times carry their zone, not just an offset. Every timestamp comes back three ways at once: the instant with an explicit offset, the IANA zone the entry was written in, and a flag for whole-day entries. Only the zone survives a daylight-saving change — an event pinned to +02:00 moves an hour every winter — and a whole-day entry reported as midnight is how a public holiday shows up as a one-minute appointment.

Shortened. The full README is on GitHub.

Nothing above is checked by us. What we check is on the safety report.

CalDAV calendars: common questions

Is CalDAV calendars MCP server safe?: Mostly: it is graded B (83/100). Read the CalDAV calendars safety report
How do I install CalDAV calendars?: It runs on your machine. Copy the Claude Code, Cursor, VS Code or Claude Desktop config from the install section.
Does CalDAV calendars need an API key?: Yes. The registry entry asks for CALDAV_PASSWORD, CALDAV_TOKEN.
Is CalDAV calendars maintained?: The last commit was 22 days ago (2026-10-13). The latest release is v0.1.5.
How does CalDAV calendars compare with other MCP servers?: safety score 83/100 (higher than 65% of 48,255 servers); tools 22 (the typical server has 7); tools that change things 41% (typical: 0%. Fewer write tools means less an agent can break). Full comparison.

Run it through the gateway

Local package. It runs on your machine, not through the gateway.

Rating: —
Safety grade: B · 83/100
Stars: 0
Downloads/wk: 74
Price: Free
Licence: MIT
Transport: Local · mixed
Version: 0.1.5
Category: Everything else
Last release: 2026-10-13

Credentials it needs

CALDAV_URLRoot of the CalDAV server, e.g. https://dav.example.net. A calendar collection URL also works.
CALDAV_USERNAMEAccount name. Most hosted services want an app-specific password with it.
CALDAV_PASSWORDsecretPassword or app-specific password. Deleted from the environment once read.
CALDAV_TOKENsecretBearer token, as an alternative to username and password. Not both.
CALDAV_CALENDARSComma-separated calendars this server may touch, by path or final path segment. Default: all of them.
CALDAV_TIMEZONEIANA zone for timestamps that carry no offset, e.g. Europe/Berlin (default: UTC)
CALDAV_USER_EMAILThe address you are invited as, so respond_to_event can find your own attendee line
CALDAV_MAX_EVENTSEntries a listing returns by default, 1 to 500 (default: 100)
CALDAV_READ_ONLYSet to true to register only the read tools (default: false)
CALDAV_INSECURE_TLSSet to true to accept a self-signed certificate on the configured host only (default: false)
CALDAV_ALLOW_PLAINTEXTSet to true to allow a plain http:// URL to a host that is not loopback, which sends the credentials unencrypted (default: false)
CALDAV_ALLOW_TOOLSComma-separated tool names or list_* prefixes to register; 'essential' selects a curated preset (default: all tools)
CALDAV_DENY_TOOLSComma-separated tool names or list_* prefixes to remove from whatever the allow list left
ELICITATIONDeliberately unprefixed, and reaches every MCP server in the environment. Set to false to make guarded tools use the two-call token instead of a dialog (default: true)
CALDAV_URLRoot of the CalDAV server, e.g. https://dav.example.net. A calendar collection URL also works.
CALDAV_USERNAMEAccount name. Most hosted services want an app-specific password with it.
CALDAV_PASSWORDsecretPassword or app-specific password. Deleted from the environment once read.
CALDAV_TOKENsecretBearer token, as an alternative to username and password. Not both.
CALDAV_CALENDARSComma-separated calendars this server may touch, by path or final path segment. Default: all of them.
CALDAV_TIMEZONEIANA zone for timestamps that carry no offset, e.g. Europe/Berlin (default: UTC)
CALDAV_USER_EMAILThe address you are invited as, so respond_to_event can find your own attendee line
CALDAV_MAX_EVENTSEntries a listing returns by default, 1 to 500 (default: 100)
CALDAV_READ_ONLYSet to true to register only the read tools (default: false)
CALDAV_INSECURE_TLSSet to true to accept a self-signed certificate on the configured host only (default: false)
CALDAV_ALLOW_PLAINTEXTSet to true to allow a plain http:// URL to a host that is not loopback, which sends the credentials unencrypted (default: false)
CALDAV_ALLOW_TOOLSComma-separated tool names or list_* prefixes to register; 'essential' selects a curated preset (default: all tools)
CALDAV_DENY_TOOLSComma-separated tool names or list_* prefixes to remove from whatever the allow list left
ELICITATIONDeliberately unprefixed, and reaches every MCP server in the environment. Set to false to make guarded tools use the two-call token instead of a dialog (default: true)

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