The moment it happens

Hear when a Cal.com booking is moved or cancelled

I know straight away when a meeting changes time or is called off.

Runs: The moment it happens
Apps: Cal.com
AI: Not needed
Access: API key

Send this to your assistant

Create a ClickRuntime automation: when a Cal.com booking is rescheduled or cancelled, post the attendee, the old time and the new time (or 'cancelled') to #bookings in Slack.

Paste it into your assistant. It tells you what it will send or change before it runs live.

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First time? Adding ClickRuntime to your assistant takes about two minutes.

Why use it

Why teams use this automation

A booking that moves or disappears is more disruptive than a new one. The sales engineer who has prepared for a Thursday demo needs to know it is now Monday; the room, the driver or the specialist who was reserved needs to be released. Cal.com emails the attendee and the organizer, but a team behind the organizer never hears about it, and someone turns up to an empty video call.

When a Cal.com booking is rescheduled or cancelled, ClickRuntime receives the event immediately and posts a message to your team. For a reschedule, it shows both the old time and the new one; for a cancellation, it says which booking was removed and who it was with.

It helps teams in which people other than the booking owner depend on the schedule, like consultants with assistants or clinics with several staff.

What you get out of it

Nobody waits for a call that moved
Posting the new time stops colleagues from showing up at the old one. Wasted waiting time is avoided on both sides of the call. Wasted waiting time is avoided on both sides of the call, which matters for busy clients.
Freed slots can be reused
A cancellation announced at once leaves time to offer the slot to someone on a waiting list. Revenue that would have been lost to an empty hour is recovered. A cancellation announced at once leaves time to offer the slot to someone on a waiting list, and revenue that would have been lost to an empty hour is recovered.
Old and new times appear together
Seeing both the previous time and the replacement removes confusion. Calendar entries are updated correctly instead of being guessed from memory. Seeing both the previous time and the replacement removes confusion, and calendars are updated correctly instead of being guessed from memory or half-remembered messages.
Prep work is not wasted
When a meeting is cancelled, the person preparing for it can stop. Avoiding a hour of research on a call that will not happen is a small saving that adds up.
Patterns of cancellation become visible
A channel record of cancellations shows which event types or days attract the most. Spotting that guides reminders, deposits or availability changes. Spotting that pattern guides decisions about reminders, deposits or availability changes, which can reduce the number of late cancellations over time.

How it works

What happens, step by step

When a Cal.com booking is rescheduled or cancelled, Cal.com tells ClickRuntime straight away.
For a cancellation, ClickRuntime notes who it was with, the meeting title and the time it was meant to happen.
For a reschedule, it notes the old time and the new time.
It posts the change to #bookings in Slack, so nobody turns up to a meeting that moved.

Before it runs live

Connect Cal.com
Paste your automation's link into the other app's webhook settings

What you get

RunsThe moment it happens

Hear when a Cal.com booking is moved or cancelledjust nowSucceeded

Slack · #bookingsRescheduled: Dana Reyes, Intro call from 2026-10-22T14:00Z to 2026-10-23T16:00Z

Build your own

Need it to work differently?

This template is a starting point. Copy the prompt and change it, or describe a different automation from scratch, with your own conditions, more apps or an AI step. Your assistant writes it, tests it and runs it on ClickRuntime.

Your own rules
Conditions, thresholds, filters and exceptions, written the way you'd explain them to a colleague.
Any number of apps
One automation can read from one app and update several others. Over 248 apps are ready, and anything with an API works too.
AI where it helps
Summaries, classification, extraction and drafts use ClickRuntime's built-in AI, with no extra key.
On a schedule or on each event
Runs as often as every 5 minutes, or the moment an app sends an event, and keeps track of what it already handled.

Changes you can ask for

Act only on the items that match your own rules, and skip the rest
Add an AI step, for example to summarize, sort or draft a reply
Add another app, for example also send it to Slack
Combine it with other Cal.com steps into one automation

Under the hood

The code that runs this automation

This is the Python script that runs each time the automation starts. Your AI assistant writes it for you when you send the prompt, and you allow each step in your assistant. To change how the automation works, describe the change to your assistant and it updates the script for you. For every function it can use, see the script reference.

rescheduled_cancelled_alert.pyexample

from clickruntime import on_event, notify

@on_event
def handle(event):
    e = event.json or {}
    kind = e.get("triggerEvent")
    if kind not in ("BOOKING_RESCHEDULED", "BOOKING_CANCELLED"):
        return {"posted": False}
    p = e.get("payload") or {}
    who = ", ".join(a["name"] for a in p.get("attendees", []))
    if kind == "BOOKING_CANCELLED":
        text = f"Cancelled: {who}, {p.get('title')} at {p.get('startTime')}"
    else:
        text = f"Rescheduled: {who}, {p.get('title')} from {p.get('rescheduleStartTime')} to {p.get('startTime')}"
    notify.slack(text, channel="#bookings")
    return {"posted": True, "event": kind}

FAQ

Common questions

Are rescheduled and cancelled bookings posted separately?

They arrive as different Cal.com event types, and the workflow handles both. The message says clearly whether the booking was rescheduled or cancelled and, for reschedules, includes the previous and new times so the team can adjust calendars.

Does it include the reason a person gave for cancelling?

If the person entered a reason and Cal.com includes it in the event, it can be added to the message. Whether a reason is available depends on how the cancellation was made, so it will not appear every time.

Can I be alerted only about cancellations?

Yes. If you do not need the reschedule messages, the workflow can be limited to cancellations. Tell your AI assistant which events you want and review the change before it goes live. Everything else is left out of the channel.

What permissions does it need?

API key. Nothing else in your accounts is used.

Does it need AI?

No. It runs without AI, so it doesn't use your plan's AI allowance.

How many runs does it use?

One run for each event the app sends.

Can I change how it works?

Yes. Describe the change to your AI assistant, for example a different schedule, channel or filter. It updates the automation, tests it and tells you what changed.

The moment it happens