The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the CallChatSyn listing page.
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).
| 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 |
Add this URL as a custom connector (Claude: Settings → Connectors → Add custom connector; Cursor and others: a Streamable HTTP server):
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.
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.
MIT licensed.