CallChatSyn
Answer small-business customer questions from FAQs, list open appointment times, and book them.
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
claude mcp add --transport http callchatsyn 'https://callchatsyn.com/api/mcp' --header 'Authorization: <Optional. '\''Bearer ccs_live_…'\'' from Dashboard > Developers. Without it, the public demo business is used and bookings are dry runs.>'{
"mcpServers": {
"callchatsyn": {
"type": "http",
"url": "https://callchatsyn.com/api/mcp",
"headers": {
"Authorization": "<Optional. 'Bearer ccs_live_…' from Dashboard > Developers. Without it, the public demo business is used and bookings are dry runs.>"
}
}
}
}Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
CallChatSyn MCP server
Let an AI assistant (Claude, Cursor, any MCP client) answer customer questions and book appointments for a small business, using that business's own FAQs and opening hours on CallChatSyn.
Free for the first 1,000 businesses (founder offer: 100 API calls a day, 2,000 a month).
Tools
| Tool | Changes data? | What it does |
|---|---|---|
answer_customer_question | No (read-only) | Answers from the business's FAQs and order data (English/Chinese); flags booking and "talk to a person" requests |
list_open_times | No (read-only) | Next open times (up to 5, next 7 days) in the business's time zone, plus services and locations; from CallChatSyn hours or the business's connected Cal.com |
book_appointment | Yes, creates a booking | Books one of those times and returns its id; the business is notified and, with Cal.com connected, the booking is created there. Not idempotent. Demo key = dry run |
cancel_appointment | Yes, cancels a booking | Cancels a booking by id (also in Cal.com if connected). To reschedule: cancel, then book a new time. Demo key = dry run |
Remote server (nothing to install)
Add this URL as a custom connector (Claude: Settings → Connectors → Add custom connector; Cursor and others: a Streamable HTTP server):
https://callchatsyn.com/api/mcpWithout a key it uses the demo business. To act for your own business, send the header Authorization: Bearer ccs_live_.... Also listed in the official MCP Registry as com.callchatsyn/callchatsyn.
Local setup (npx)
- Create a CallChatSyn account, add FAQs and opening hours, then Dashboard → Developers → claim founder access → create an API key.
- Add to your MCP client config:
{
"mcpServers": {
"callchatsyn": {
"command": "npx",
"args": ["-y", "github:oneappsworld/callchatsyn-mcp"],
"env": { "CALLCHATSYN_API_KEY": "ccs_live_..." }
}
}
}Keep the key private; it acts for one business.
No key yet? Leave CALLCHATSYN_API_KEY out and the server uses the public demo key (ccs_demo_public): answers come from a demo business and bookings are dry runs, so you can try every tool before signing up.
Notes
- Answers are rule-based FAQ matching (fast, predictable), not free-form generation.
- API docs and OpenAPI spec: https://callchatsyn.com/developers · https://callchatsyn.com/openapi.json
MIT licensed.
Frequently asked questions
What is CallChatSyn?
Answer small-business customer questions from FAQs, list open appointment times, and book them.
How do I install CallChatSyn?
It runs as a remote server. In Claude Code: claude mcp add --transport http callchatsyn 'https://callchatsyn.com/api/mcp' --header 'Authorization: <Optional. '\''Bearer ccs_live_…'\'' from Dashboard > Developers. Without it, the public demo business is used and bookings are dry runs.>'. For other clients, paste the JSON configuration from this page into their MCP settings.
Does CallChatSyn need an API key?
Yes. It expects Authorization, which you set in its configuration.
Is CallChatSyn open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains CallChatSyn?
It is published by oneappsworld. AI.tn lists it but does not maintain or endorse it.
From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.