CallSync MCP Server

by callsyncapp Your server? Claim it

answering

CallSync is answering right now. Last checked 13 min ago.

Search business calls, review conversation insights, and manage CRM follow-ups with CallSync.

Uptime history 21 days of history · worst day 99%

21 days agonow

100.0%

Uptime 24h

91 of 91 checks

—

Tools

hidden behind auth

240 ms

Response time

average over 24h

OAuth sign-in

Access

streamable-http

CallSync missed one check this week

Everything else answered, so this is steady rather than shaky. We check every 15 minutes, which is how a one-off gets told apart from the start of a pattern, and how you hear about the next one within the hour instead of 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.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add callsync --transport http https://mcp.callsyncapp.com/connect

Settings → Connectors → Add custom connector, then paste this address

https://mcp.callsyncapp.com/connect

~/.codex/config.toml

[mcp_servers.callsync]
url = "https://mcp.callsyncapp.com/connect"

.cursor/mcp.json

{
  "mcpServers": {
    "callsync": {
      "url": "https://mcp.callsyncapp.com/connect"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "callsync": {
      "type": "http",
      "url": "https://mcp.callsyncapp.com/connect"
    }
  }
}

This endpoint answered with an authorization challenge. The server is running, and it signs you in through your browser: there is no API key to paste.

Endpoints

URL	Transport	State	Latency	Checked
https://mcp.callsyncapp.com/connect	streamable-http	sign-in	158 ms	13 min ago

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CallSync — questions

Answers built from our own checks of this server.

Why is there no tool list for CallSync?

The server answered our handshake with an authorization challenge, so it is running — but it will not describe its tools to an anonymous client. To see them you need to connect with your own credentials. We record it as alive, not as broken: 100.0% of checks in the last 24 hours got a reply.

Is CallSync working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 240 ms. The bar chart above shows every period we have measured.

How do I connect CallSync?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address. You sign in through your browser once and the client keeps the session: no key to copy, and it refuses anonymous clients.

How do you sign in to CallSync?

No API key is involved. CallSync answers our knock with an OAuth challenge, so you authorise it once in your browser and the client keeps the session. That is also why we see no tool list: it will not describe itself to an anonymous client, and that is the server working as intended, not a fault.

How fast is CallSync?

It answers our handshake in 240 ms on average, which is faster than 59% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.