Sync Day is listed as active in the registry but did not answer our last check. It exposes 8 tools.
Free no-signup group scheduling; share a link and rank times by who's free.
Uptime history
17 days of history · worst day 0%
17 days agonow
2.2%
Uptime 24h
2 of 91 checks
8
Tools
read from the server
531 ms
Response time
average over 24h
open, no key
Access
streamable-http
Sync Day does not always answer
Over the last week it answered 0.5% of our checks. We check every 15 minutes, so you hear about the next outage within the hour — not from your users.
Connect this server
Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 13 min ago.
run in your terminal
claude mcp add sync-day --transport http https://sync.day/mcp/mcp~/Library/Application Support/Claude/claude_desktop_config.json
{
"mcpServers": {
"sync-day": {
"url": "https://sync.day/mcp/mcp"
}
}
}~/.codex/config.toml
[mcp_servers.sync-day]
url = "https://sync.day/mcp/mcp".cursor/mcp.json
{
"mcpServers": {
"sync-day": {
"url": "https://sync.day/mcp/mcp"
}
}
}.vscode/mcp.json
{
"mcpServers": {
"sync-day": {
"url": "https://sync.day/mcp/mcp"
}
}
}Available tools 8
Read directly from the server with tools/list, grouped by what they act on.
If a tool disappears, we record the date.
event
create_event
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}.
get_event
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.
update_event
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 Existing picks are kept; those no longer valid starts are just hidden.
decide
decide_time
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.
parse
parse_event_text
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'.
participant
remove_participant
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
submit_availability
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.
vote
vote_time
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`.
Endpoints
| URL | Transport | State | Latency | Checked |
|---|---|---|---|---|
| https://sync.day/mcp/mcp | streamable-http | answering | 405 ms | 13 min ago |
Alternatives to Sync Day
same job, measured the same way
D
Whenly — group scheduling for AI agents
by workers-notdown-app-whenly
Agent creates a group-scheduling poll, gets a shareable link, and reads the best meeting time.
WhenMeet.me — group scheduling
by whenmeet
Group meeting scheduler — rank times everyone's free across Google & Outlook, book Meet/Teams.
Whenna
by whenna
Group scheduling: create a plan link, mark availability, get best times, lock the final time.
C
Transfer
by 83blue-upload
Free no-signup file transfer for AI agents. Files encrypted at rest (video excepted). Share by url.
All
by veezee
Real-time LinkedIn, X (Twitter) and Reddit data for AI agents. Free key, self-minted, no signup.
Meet.bot MCP
by meet
AI-native scheduling and booking: check availability, book meetings, share links.
Timergy
by dockerdiscordcontrol
Create scheduling polls, vote, and finalize times from AI agents.
Make Bracket Online MCP
by rocnubie
Create, run, and share brackets for decisions, tournaments, and group votes with no sign-up
Sync Day — questions
Answers built from our own checks of this server.
What can Sync Day do?
It exposes 8 tools, read directly from the server on our last check. Among them: create_event, decide_time, get_event, parse_event_text, remove_participant, submit_availability and 2 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README.
How MCP servers expose tools in the first place →
Is Sync Day working right now?
We send a real MCP handshake every 15 minutes. Over the last 24 hours 2 of 91 checks got a reply (2.2%), average response time 531 ms. The bar chart above shows every period we have measured.
The registry lists Sync Day as active — why does it not respond?
The official MCP registry stores what the author submitted; it does not verify that the server still runs. We check the endpoint ourselves, and this one does not answer. Catalogues that copy the registry without checking will show it as working.
How do I connect Sync Day?
Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.
Does Sync Day need an API key?
No. Sync Day completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 8 of them are readable on this page. This is what we observed, not what the docs claim.
How fast is Sync Day?
It answers our handshake in 531 ms on average, which is faster than 29% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.