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io.github.syncday-app/sync-day

by syncday-app · remote · no sign-in to list tools · v1.0.0 · published by GitHub user syncday-app

Free no-signup group scheduling; share a link and rank times by who's free.

Deletes · 1Changes · 6
CompareRegistry entry

8 tools: 1 can delete or cancel things, 6 change things and 1 only read.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http sync-day https://sync.day/mcp/mcp

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

8 tools

Deletes or cancels 1Claude Code: deny
  • remove_participantOrganiser only: remove one participant by name (the oldest row with that name when it repeats), together with their vote.No findings

    Why it is in this group

    • The name "remove_participant" says "remove": a word for removing or ending something.
    • The server marks it destructive (destructiveHint: true).
    Description, as the server wrote it
    Organiser only: remove one participant by name (the oldest row with that name when it repeats), together with their vote. Requires the adminKey from create_event.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: true
    • openWorldHint: false
Changes things 6Claude Code: ask
  • create_eventCreate a sync.day availability poll and get its share link.No findings

    Why it is in this group

    • The name "create_event" says "create": a word for a change.
    Description, as the server wrote it
    Create a sync.day availability poll and get its share link. Candidate days run from startDate to endDate (inclusive; or give days instead). Each day offers candidate START times from hourFrom, every startStepMinutes, as long as start + durationMinutes <= hourTo. Returns slug, public url (share this), adminUrl and adminKey (keep private; needed for update_event / remove_participant). Example: 周六周日下午聚餐 3 小时 -> {title:'周末聚餐', startDate:'2026-09-05', endDate:'2026-09-06', hourFrom:13, hourTo:18, durationMinutes:180, startStepMinutes:60}.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: false
    • openWorldHint: false
  • decide_timeOrganiser only: settle on a start time (locks availability picking and voting; the page shows 已定).No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    Organiser only: settle on a start time (locks availability picking and voting; the page shows 已定). Pass start=null to reopen. Requires the adminKey from create_event.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • parse_event_textTurn a natural-language sentence (Chinese works best) into create_event input using sync.day's AI parser.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Turn a natural-language sentence (Chinese works best) into create_event input using sync.day's AI parser. Does NOT create anything; review the result, then call create_event. Example: '下周六或周日下午聚餐，大概 3 小时'.

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: true
  • submit_availabilitySave (or replace) one person's availability: the candidate start keys they can make, from get_event.startOptions.No findings

    Why it is in this group

    • The name "submit_availability" says "submit": a word for a change.
    Description, as the server wrote it
    Save (or replace) one person's availability: the candidate start keys they can make, from get_event.startOptions. The person is identified by `identity`, not by name: the same identity later overwrites the same row (and can rename it), a different identity with the same name is a second participant. Keys outside the event's start options are rejected. Returns the updated ranking.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • update_eventOrganiser only: change any event settings (same fields and rules as create_event; omitted fields keep their current value; endDate wins over days).No findings

    Why it is in this group

    • The name "update_event" says "update": a word for a change.
    Description, as the server wrote it
    Organiser only: change any event settings (same fields and rules as create_event; omitted fields keep their current value; endDate wins over days). Existing picks are kept; those no longer valid starts are just hidden.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • vote_timeApproval voting: set every start one person accepts (replaces their earlier approvals; an empty list clears them).No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    Approval voting: set every start one person accepts (replaces their earlier approvals; an empty list clears them). The voter is the `identity` used in submit_availability and must have at least one start saved. Only keys listed in get_event.voteOptions are accepted; the error lists the current options otherwise. Rejected once the organiser decided. Example: {slug:'calm-otter-4821', identity:'3f9a1c77b2e04d5e8a61f0c9d2b7e415', starts:['2026-09-05T15:00','2026-09-06T10:00']}. `start` is shorthand for a single-item `starts`.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Only reads 1Claude Code: allow
  • get_eventRead an event: settings, every candidate start key per day (startOptions), who has answered (participants with their start keys; names may repeat), the top 10 start times by head-c…No findings

    Why it is in this group

    • The name "get_event" says "get": a word for reading.
    Description, as the server wrote it
    Read an event: settings, every candidate start key per day (startOptions), who has answered (participants with their start keys; names may repeat), the top 10 start times by head-count (ranked), the starts EVERYONE with picks can make with their votes (voteOptions), each person's vote (votes) and decidedStart. No key needed.

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http sync-day https://sync.day/mcp/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__sync-day__get_event"
    ],
    "ask": [
      "mcp__sync-day__create_event",
      "mcp__sync-day__parse_event_text",
      "mcp__sync-day__submit_availability",
      "mcp__sync-day__update_event",
      "mcp__sync-day__vote_time",
      "mcp__sync-day__decide_time"
    ],
    "deny": [
      "mcp__sync-day__remove_participant"
    ]
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as sync-day. Review it before you use it.