Sync Day MCP server

• create_eventwrite actionFree

  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}.

• decide_timeFree

  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.

• get_eventFree

  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.

• parse_event_textFree

  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'.

• remove_participantwrite actionFree

  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.

• submit_availabilitywrite actionFree

  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.

• update_eventwrite actionFree

  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 Existing picks are kept; those no longer valid starts are just hidden.

• vote_timeFree

  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`.

• –Code scanremote-only server, no package to scann/a
• Live reliabilityremote reachable in 1782ms20/20
• Tool poisoning8 tool descriptions checked15/15
• Auth qualityopen endpoint exposes 4 write-action tools with no auth3/15
• Maintenanceno repository listed3/15
• Maintainer identityno repository or website to verify2/10

Sync Day: common questions

Is Sync Day MCP server safe?

With care: it is graded C, so read the findings first (57/100). Read the Sync Day safety report

How do I install Sync Day?

It runs remotely at sync.day. Add it to Claude Code, Claude Desktop or Cursor with the snippets above, or call it through the mcp.market gateway without installing anything.

Does Sync Day need an API key?

Not as far as the registry entry and our scan can tell: no credentials are declared or required.

Is Sync Day maintained?

The latest release is v1.0.0.

Is Sync Day up?

100% of our last 5 checks got an answer. We check remote servers about four times a day.

What can I use instead of Sync Day?

Servers from other publishers that do the same job: Mencoro MCP server, x402 Bazaar Rank MCP server and Chembl MCP server. Compare all Sync Day alternatives.