> ## Documentation Index
> Fetch the complete documentation index at: https://coss-mintlify-0e24fcb1.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Webhooks
Webhooks offer a great way to automate the flow with other apps when invitees schedule, cancel or reschedule events, or when the meeting ends.
The webhook subscription allows you to listen to specific trigger events, such as when a booking has been scheduled, for example. You can always listen to the webhook by providing a custom subscriber URL with your own development work. However, if you wish to trigger automations without any development work, you can use the integration with Zapier which connects Cal.com to your apps.
### Webhook scope levels
Webhooks can be created at multiple levels of scope, each determining which events they apply to:
* **User-level**:
Triggers for all event types owned by the user (excluding team-managed types).
* **Event-type level**:
Triggers only for a specific event type. Useful for fine-grained control.
* **Team-level**:
Applies to team event types (i.e., Collective and Round Robin) within the specified team.
In the case of Managed events, bookings are made on the child event types, not the parent team event. Because of this, team-level webhooks will **not** trigger for managed events unless one of the following is true:
* You create a webhook directly on the parent event type (recommended), or
* You create individual webhooks on the child event types (owned by users).
💡 **Note:**
Users can create webhooks that apply to their own event types, including child events under a managed event, even if a team-level webhook exists.
* **Organization-level**:
Applies to all team event types across all teams within the organization.
### Creating a webhook subscription
To create a new webhook subscription, visit `/settings/developer/webhooks` and proceed to enter the following details:
1. Subscriber URL: The listener URL where the payload will be sent to, when an event trigger is triggered.
The subscriber URL must meet the following requirements:
* **Cal.com SaaS**: Only HTTPS URLs are accepted. HTTP, private/internal IP addresses (e.g., `10.x.x.x`, `192.168.x.x`, `127.0.0.1`), and `localhost` are blocked.
* **Self-hosted**: Both HTTP and HTTPS URLs are accepted, and private IP addresses are allowed for internal webhooks.
* **All environments**: Cloud metadata endpoints (e.g., `169.254.169.254`) and non-HTTP protocols (e.g., `ftp://`, `file://`) are always blocked.
If your subscriber URL does not meet these requirements, the webhook creation request will be rejected with an error.
2. Event triggers: You can decide which triggers specifically to listen to. Currently, we offer listening to `Booking Cancelled`, `Booking Created`, `Booking Rescheduled`, `Booking Rejected`, `Booking Requested`, `Booking Paid`, `Booking Payment Initiated`, `Booking No-Show Updated`, `Meeting Started`, `Meeting Ended`, `Recording Ready`, `Recording Transcription Generated`, `Instant Meeting Created`, `Instant Meeting Accepted`, `Out of Office Created`, `After Hosts Cal Video No-Show`, `After Guests Cal Video No-Show`, `Form Submitted`, and `Form Submitted (No Event)`.
3. Secret: You can provide a secret key with this webhook and then [verify it](/docs/core-features/webhooks#verifying-the-authenticity-of-the-received-payload) on the subscriber URL when receiving a payload to confirm if the payload is authentic or adulterated. You can leave it blank, if you don't wish to secure the webhook with a secret key.
4. Custom Payload: You have the option to [customize the payload](/docs/core-features/webhooks#adding-a-custom-payload-template) you receive when a subscribed event is triggered.
### Expectations with the triggers
| **Event** | **Triggers When...** |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Booking Created | A new booking is successfully created. |
| Booking Cancelled | A booking is cancelled by the host, attendee, or via API. |
| Booking Rejected | A booking request is explicitly rejected by the host. |
| Booking Requested | A booking requiring confirmation from the host is submitted. |
| Booking Paid | Payment for a booking is completed. |
| Booking Payment Initiated | A payment attempt is initiated (before confirmation). |
| Booking No-Show Updated | A host or attendee is marked as a no-show after the meeting. |
| Meeting Started | At the scheduled start time of the meeting. Uses a [flat payload format](#meeting-started--meeting-ended-flat-format). Automatically cancelled if the booking is cancelled or rescheduled. |
| Meeting Ended | At the scheduled end time of the meeting. Uses a [flat payload format](#meeting-started--meeting-ended-flat-format). Automatically cancelled if the booking is cancelled or rescheduled. |
| Recording Ready | A meeting recording is available and ready to access. |
| Recording Transcription Generated | A transcription of the meeting recording is successfully generated. |
| Instant Meeting Created | An instant (ad-hoc) meeting is created. |
| Instant Meeting Accepted | A host accepts an instant meeting and becomes the organizer. Only fires for the first host to accept. |
| Out of Office Created | A user adds a new Out of Office entry to their availability. |
| After Hosts Cal Video No-Show | The host did not show up to a Cal Video meeting in the first `n` minutes, as set up in the configuration. |
| After Guests Cal Video No-Show | The attendee did not show up to a Cal Video meeting in the first `n` minutes, as set up in the configuration. |
| Form Submitted | A form is submitted as part of a routing form **with** a scheduled event. |
| Form Submitted (No Event) | A form is submitted **without** a scheduled event (form-only flow). |
### Seated event types
For event types with [seats enabled](/event-types/offer-seats), the `attendees` array in webhook payloads contains only the attendee associated with the specific seat that triggered the webhook. For example, when a new seat is booked, the webhook includes only that seat's attendee — not all attendees across the entire booking. This applies to all booking-related triggers (`BOOKING_CREATED`, `BOOKING_RESCHEDULED`, etc.).
### Example webhook payloads
Most webhook events use a nested payload format with booking details inside a `payload` object. The `MEETING_STARTED` and `MEETING_ENDED` events use a different flat format where booking fields are at the top level.
#### Booking events (nested format)
Events like `BOOKING_CREATED`, `BOOKING_CANCELLED`, `BOOKING_RESCHEDULED`, and most other triggers use this format:
```json theme={null}
{
"triggerEvent": "BOOKING_CREATED",
"createdAt": "2023-05-24T09:30:00.538Z",
"payload": {
"type": "60min",
"title": "60min between Pro Example and John Doe",
"description": "",
"additionalNotes": "",
"customInputs": {},
"startTime": "2023-05-25T09:30:00Z",
"endTime": "2023-05-25T10:30:00Z",
"organizer": {
"id": 5,
"name": "Pro Example",
"email": "owner@acme.com",
"username": "owner90",
"usernameInOrg": "owner",
"timeZone": "Asia/Kolkata",
"language": {
"locale": "en"
},
"timeFormat": "h:mma"
},
"responses": {
"name": {
"label": "your_name",
"value": "John Doe"
},
"email": {
"label": "email_address",
"value": "john.doe@example.com"
},
"location": {
"label": "location",
"value": {
"optionValue": "",
"value": "inPerson"
}
},
"notes": {
"label": "additional_notes"
},
"guests": {
"label": "additional_guests"
},
"rescheduleReason": {
"label": "reschedule_reason"
}
},
"userFieldsResponses": {},
"attendees": [
{
"email": "john.doe@example.com",
"name": "John Doe",
"timeZone": "Asia/Kolkata",
"language": {
"locale": "en"
}
}
],
"location": "Calcom HQ",
"destinationCalendar": {
"id": 10,
"integration": "apple_calendar",
"externalId": "https://caldav.icloud.com/1234567/calendars/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX/",
"userId": 5,
"eventTypeId": null,
"credentialId": 1
},
"hideCalendarNotes": false,
"requiresConfirmation": null,
"eventTypeId": 7,
"seatsShowAttendees": true,
"seatsPerTimeSlot": null,
"uid": "bFJeNb2uX8ANpT3JL5EfXw",
"appsStatus": [
{
"appName": "Apple Calendar",
"type": "apple_calendar",
"success": 1,
"failures": 0,
"errors": [],
"warnings": []
}
],
"eventTitle": "60min",
"eventDescription": "",
"price": 0,
"currency": "usd",
"length": 60,
"bookingId": 91,
"metadata": {},
"status": "ACCEPTED"
}
}
```
#### Meeting started / meeting ended (flat format)
`MEETING_STARTED` and `MEETING_ENDED` webhooks use a flat payload format where booking fields are at the top level alongside `triggerEvent`, rather than nested inside a `payload` object. These webhooks are delivered at the scheduled start and end time of the meeting respectively.
```json theme={null}
{
"triggerEvent": "MEETING_STARTED",
"id": 91,
"uid": "bFJeNb2uX8ANpT3JL5EfXw",
"title": "60min between Pro Example and John Doe",
"description": "",
"startTime": "2023-05-25T09:30:00.000Z",
"endTime": "2023-05-25T10:30:00.000Z",
"location": "https://cal.app/video/abc123",
"status": "ACCEPTED",
"paid": false,
"createdAt": "2023-05-24T09:30:00.538Z",
"updatedAt": "2023-05-24T09:30:00.538Z",
"userId": 5,
"eventTypeId": 7,
"metadata": {},
"responses": {
"name": {
"label": "your_name",
"value": "John Doe"
},
"email": {
"label": "email_address",
"value": "john.doe@example.com"
}
},
"user": {
"email": "owner@acme.com",
"name": "Pro Example",
"username": "owner90",
"timeZone": "Asia/Kolkata",
"locale": "en"
},
"attendees": [
{
"id": 201,
"name": "John Doe",
"email": "john.doe@example.com",
"timeZone": "Asia/Kolkata",
"locale": "en",
"noShow": false
}
],
"payment": [],
"references": [
{
"id": 42,
"type": "daily_video",
"uid": "abc123",
"meetingId": "abc123",
"meetingUrl": "https://cal.app/video/abc123"
}
]
}
```
`MEETING_STARTED` and `MEETING_ENDED` webhooks do not support [custom payload templates](#adding-a-custom-payload-template). They always send the full booking data in the flat format shown above.
If a booking is cancelled or rescheduled before the meeting time, the scheduled `MEETING_STARTED` and `MEETING_ENDED` webhooks for that booking are automatically cancelled.
#### Instant meeting accepted
The `INSTANT_MEETING_ACCEPTED` webhook fires when a host accepts an instant meeting request through the connect-and-join flow. It only triggers for the first host to accept — if another host has already accepted the booking, the webhook is not sent again. This trigger is available for team event types only.
The payload includes the booking `status` (set to `ACCEPTED`), the accepting host as the `organizer` with their locale and time format preferences, the guest `attendees` list, booking `responses`, and a `metadata` object containing the `videoCallUrl` for the meeting.
```json theme={null}
{
"triggerEvent": "INSTANT_MEETING_ACCEPTED",
"createdAt": "2025-04-17T10:01:00.000Z",
"payload": {
"bookingId": 142,
"bookingUid": "aB3kL9mNpQ7rS1tU",
"eventTypeId": 15,
"status": "ACCEPTED",
"title": "Instant meeting between Team and Jane Smith",
"startTime": "2025-04-17T10:00:00.000Z",
"endTime": "2025-04-17T10:30:00.000Z",
"organizer": {
"id": 8,
"name": "Host Example",
"email": "host@example.com",
"username": "host-example",
"timeZone": "America/New_York",
"language": {
"locale": "en"
},
"timeFormat": "h:mma",
"utcOffset": -300
},
"attendees": [
{
"email": "jane.smith@example.com",
"name": "Jane Smith",
"timeZone": "Europe/London",
"language": {
"locale": "en"
},
"utcOffset": 60
}
],
"responses": {
"name": {
"label": "your_name",
"value": "Jane Smith"
},
"email": {
"label": "email_address",
"value": "jane.smith@example.com"
}
},
"location": "integrations:daily",
"metadata": {
"videoCallUrl": "https://cal.app/video/aB3kL9mNpQ7rS1tU"
}
}
}
```
### Subscriber URL requirements
Cal.com validates webhook subscriber URLs to protect against server-side request forgery (SSRF). The validation rules depend on whether you are using Cal.com Cloud or a self-hosted instance.
**Cal.com Cloud:**
* The subscriber URL must use HTTPS.
* URLs pointing to private or internal IP addresses (such as `10.x.x.x`, `172.16.x.x`, `192.168.x.x`, or `127.0.0.1`) are blocked.
* Cloud metadata endpoints (such as `169.254.169.254`) are blocked.
* Hostnames that resolve to private IP addresses via DNS are also blocked.
**Self-hosted:**
* Both HTTP and HTTPS URLs are accepted, so you can use internal services as webhook targets.
* Private IP addresses are allowed for internal webhooks.
* Cloud metadata endpoints are still blocked for security, since self-hosted instances may run on cloud infrastructure.
If your subscriber URL does not meet these requirements, the webhook creation or update request will fail with a `400` error indicating the URL is not allowed.
### Verifying the authenticity of the received payload
1. Simply add a new **secret key** to your webhook and save.
2. Wait for the webhook to be triggered (event created, cancelled, rescheduled, or meeting ended)
3. Use the **secret key** to create an `hmac`, and update that with the webhook payload received to create an SHA256.
4. Compare the hash received in the header of the webhook `(X-Cal-Signature-256)` with the one created using the **secret key** and the body of the payload. If they don't match, the received payload was adulterated and cannot be trusted.
### Adding a custom payload template
Customizable webhooks are a great way reduce the development effort and in many cases remove the need for a developer to build an additional integration service.
An example of a custom payload template is provided here:
```json theme={null}
{
"content": "A new event has been scheduled",
"type": "{{type}}",
"name": "{{title}}",
"organizer": "{{organizer.name}}",
"booker": "{{attendees.0.name}}"
}
```
where `{{type}}` represents the event type slug and `{{title}}` represents the title of the event type. Note that the variables should be added with a double parenthesis as shown above. Here’s a breakdown of the payload that you would receive via an incoming webhook, with an exhaustive list of all the supported variables provided below:
#### Webhook variable list
| Variable | Type | Description |
| ------------------ | ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| triggerEvent | String | The name of the trigger event \[BOOKING\_CREATED, BOOKING\_RESCHEDULED, BOOKING\_CANCELLED, MEETING\_ENDED, BOOKING\_REJECTED, BOOKING\_REQUESTED, BOOKING\_PAYMENT\_INITIATED, BOOKING\_PAID, MEETING\_STARTED, RECORDING\_READY, INSTANT\_MEETING, INSTANT\_MEETING\_ACCEPTED, FORM\_SUBMITTED] |
| createdAt | Datetime | The Time of the webhook |
| type | String | The event type slug |
| title | String | The event type name |
| startTime | Datetime | The event's start time |
| endTime | Datetime | The event's end time |
| description | String | The event's description as described in the event type settings |
| location | String | Location of the event |
| organizer | Organizer | The organizer of the event |
| attendees | Attendee\[] | The event booker & any guests. For [seated event types](/event-types/offer-seats), this contains only the attendee for the specific seat that triggered the webhook. |
| uid | String | The UID of the booking |
| rescheduleUid | String | The UID for rescheduling |
| cancellationReason | String | Reason for cancellation |
| rejectionReason | String | Reason for rejection |
| team.name | String | Name of the team booked |
| team.members | String\[] | Members of the team booked |
| metadata | JSON | Contains a metadata of the booking, including the meeting URL (videoCallUrl) in case of Google Meet and Cal Video |
#### Organizer Structure
| Variable | Type | Description |
| ---------------- | ------ | --------------------------------------------------------------------- |
| name | String | Name of the organizer |
| email | Email | Email of the organizer |
| username | String | Global username of the organizer |
| usernameInOrg | String | Username of the organizer within their organization (if applicable) |
| timeZone | String | Timezone of the organizer ("America/New\_York", "Asia/Kolkata", etc.) |
| language?.locale | String | Locale of the organizer ("en", "fr", etc.) |
#### Attendee Structure
| Variable | Type | Description |
| ---------------- | ------ | -------------------------------------------------------------------- |
| name | String | Name of the attendee |
| email | Email | Email of the attendee |
| timeZone | String | Timezone of the attendee ("America/New\_York", "Asia/Kolkata", etc.) |
| language?.locale | String | Locale of the attendee ("en", "fr", etc.) |