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CallChatSyn

by callchatsyn.com · remote · no sign-in to list tools · v0.1.0 · published by com.callchatsyn

Answer small-business customer questions from FAQs, list open appointment times, and book them.

Deletes · 1Changes · 2
CompareRegistry entry

4 tools: 1 can delete or cancel things, 2 change things and 1 only read.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http callchatsyn https://callchatsyn.com/api/mcp

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

4 tools

Deletes or cancels 1Claude Code: deny
  • cancel_appointmentCancel one of the business's bookings by the 'id' that book_appointment returned.No findings

    Why it is in this group

    • The name "cancel_appointment" says "cancel": a word for removing or ending something.
    • The server marks it destructive (destructiveHint: true).
    Description, as the server wrote it
    Cancel one of the business's bookings by the 'id' that book_appointment returned. This changes data: the time becomes free again, and if the business has connected Cal.com the booking is cancelled there too (Cal.com emails the customer). Only call it after the customer has clearly asked to cancel that specific booking. To reschedule, cancel and then book a new time from list_open_times. With the demo key it's a dry run. Errors: 404 no such booking for this business, 409 already cancelled, 400 not a booking id. Returns JSON { cancelled, id, start }.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: true
    • openWorldHint: true
Changes things 2Claude Code: ask
  • answer_customer_questionAnswer a customer's message for one small business using only that business's own FAQs and order records.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Answer a customer's message for one small business using only that business's own FAQs and order records. Rule-based, not generated, so it never invents prices or opening hours; English and Chinese are detected automatically. Read-only: it never books or changes anything. Use it first for any customer message. If it returns intent 'appointment', call list_open_times next; if matched is false or intent is 'human_handoff', tell the customer a person will follow up. Authenticates with the connection's API key (Authorization: Bearer ccs_live_…); without a key it answers as a public demo business. Returns JSON { intent, lang, matched, reply, next? }.

    Annotations the server declares

    • readOnlyHint: true
    • idempotentHint: true
    • openWorldHint: false
  • book_appointmentBook one appointment for a customer.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    Book one appointment for a customer. This creates a real booking: the business is notified, and if it has connected Cal.com the booking is created there too. With the demo key it's a dry run that books nothing. Not idempotent: booking the same time twice fails the second time. Only call it after the customer has confirmed the time and service; needs a 'start' from list_open_times and the customer's email or phone. Errors: 404 the time is no longer offered (call list_open_times again), 409 it was just taken, 400 missing start, service, or both email and phone, or the business's connected calendar needs a detail the customer didn't give (the message says which, e.g. an email). Returns JSON { booked, id, start, label }; keep 'id' if the customer may want to cancel.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: false
    • openWorldHint: true
Only reads 1Claude Code: allow
  • list_open_timesList the business's next open appointment times: up to 5, soonest first, within the next 7 days, labelled in the business's time zone, plus its services and locations.No findings

    Why it is in this group

    • The name "list_open_times" says "list": a word for reading.
    Description, as the server wrote it
    List the business's next open appointment times: up to 5, soonest first, within the next 7 days, labelled in the business's time zone, plus its services and locations. Read-only. Call it before book_appointment and whenever a customer asks when they can come in. Times come from the business's CallChatSyn hours or from its connected Cal.com calendar. Returns JSON { slots: [{ start, label }], services, locations }; pass a slot's 'start' to book_appointment unchanged. An empty slots list means nothing is open this week.

    Annotations the server declares

    • readOnlyHint: true
    • idempotentHint: true
    • openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 0.1.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http callchatsyn https://callchatsyn.com/api/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__callchatsyn__list_open_times"
    ],
    "ask": [
      "mcp__callchatsyn__answer_customer_question",
      "mcp__callchatsyn__book_appointment"
    ],
    "deny": [
      "mcp__callchatsyn__cancel_appointment"
    ]
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as callchatsyn. Review it before you use it.