About CallChatSyn
CallChatSyn is an MCP server for small businesses, letting AI assistants answer customer questions from business FAQs and handle appointments. Its tools cover read-only lookups as well as booking and cancellation, with optional Cal.com connectivity.
Key features
- 01Answer from FAQs and order data
- 02List upcoming appointment times
- 03Book appointments and return IDs
- 04Cancel appointments by ID
Use cases
- 01Automate replies to common customer questions
- 02Find and offer available appointment times
- 03Book or cancel appointments for customers
MCP support
As a remote MCP server, it exposes question-answering and appointment tools to clients such as Claude and Cursor over Streamable HTTP; it can also run locally.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://callchatsyn.com/api/mcpclaude mcp add --transport http com-callchatsyn-callchatsyn https://callchatsyn.com/api/mcp{"mcpServers":{"com-callchatsyn-callchatsyn":{"type":"http","url":"https://callchatsyn.com/api/mcp"}}}Open in Cursor{"servers":{"com-callchatsyn-callchatsyn":{"type":"http","url":"https://callchatsyn.com/api/mcp"}}}Open in VS Code{"mcpServers":{"com-callchatsyn-callchatsyn":{"type":"http","url":"https://callchatsyn.com/api/mcp"}}}{"mcpServers":{"com-callchatsyn-callchatsyn":{"serverUrl":"https://callchatsyn.com/api/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
https://callchatsyn.com/api/mcpAuth requiredTools
4| Parameter | Type | Required | Description |
|---|---|---|---|
| message | string | Yes | The customer's message exactly as they wrote it (1-2,000 characters, English or Chinese). Don't rephrase or translate it. |
Details
From the project READMECallChatSyn 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/mcp
Without 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.
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.