Booker - Cal.com Docs

The booker atom is a dynamic component that facilitates the booking process for users. It allows individuals to easily select available time slots and confirm their participation in various events, streamlining the scheduling experience. It is one of the most important atoms and a critical piece of our scheduling system.

Basic usage

Below code snippet can be used to render the booker atom:

import { Booker } from "@calcom/atoms";

export default function Booker( props : BookerProps ) {
  return (
    <>
      <Booker
        eventSlug={props.eventTypeSlug}
        username={props.calUsername}
        onCreateBookingSuccess={() => {
          console.log("booking created successfully");
         }}
      />
    </>
  )
}

Team events

For team events, you must set isTeamEvent to true and provide a teamId:

import { Booker } from "@calcom/atoms";

export default function TeamBooker( props : BookerProps ) {
  return (
    <Booker
      eventSlug={props.eventTypeSlug}
      isTeamEvent={true}
      teamId={props.teamId}
      onCreateBookingSuccess={(data) => {
        console.log("Team booking created:", data);
      }}
    />
  )
}

Dynamic bookings

Dynamic bookings allow multiple users to be booked simultaneously. Pass multiple usernames as an array or a plus-separated string:

import { Booker } from "@calcom/atoms";

export default function DynamicBooker() {
  return (
    <Booker
      eventSlug="30min"
      username={["user1", "user2", "user3"]}
      // or username="user1+user2+user3"
      allowsDynamicBooking={true}
      onCreateBookingSuccess={(data) => {
        console.log("Dynamic booking created:", data);
      }}
    />
  )
}

For a demonstration of the booker atom, please refer to the video below.

It is also possible to change the booker layout into a week or column view, you just need to pass in the view prop the layout you want to use. The layouts are as follows: MONTH_VIEW, WEEK_VIEW and COLUMN_VIEW. Both the week and column layouts come with an Overlay Calendar feature, which allows users to overlay multiple calendars on top of their primary calendar. Below code snippet can be used to render the booker atom with week view

import { Booker } from "@calcom/atoms";

export default function Booker( props : BookerProps ) {
  return (
    <>
      <Booker
        view="WEEK_VIEW"
        eventSlug={props.eventTypeSlug}
        username={props.calUsername}
        onCreateBookingSuccess={() => {
          console.log("booking created successfully");
         }}
      />
    </>
  )
}

For a demonstration of the booker atom along with calendar overlay, please refer to the video below.

Advanced usage patterns

Prefilling booking form data

You can prefill booking form fields using the defaultFormValues prop:

<Booker
  eventSlug="30min"
  username="john"
  defaultFormValues={{
    firstName: "Jane",
    lastName: "Doe",
    email: "jane@example.com",
    guests: ["guest1@example.com", "guest2@example.com"],
    notes: "Looking forward to our meeting",
    // Any custom field can be prefilled
    customField: "custom value"
  }}
/>

Rescheduling bookings

To enable rescheduling, pass the rescheduleUid or bookingUid:

<Booker
  eventSlug="30min"
  username="john"
  rescheduleUid="abc123"
  onCreateBookingSuccess={(data) => {
    console.log("Booking rescheduled:", data);
  }}
/>

Custom start time

Control the first available date shown to users with the startTime prop:

<Booker
  eventSlug="30min"
  username="john"
  startTime="2025-08-20"
  // or startTime={new Date("2025-08-20")}
/>

Handling booking state changes

Monitor the booker’s internal state with onBookerStateChange:

<Booker
  eventSlug="30min"
  username="john"
  onBookerStateChange={(state) => {
    console.log("Current state:", state.state); // "loading" | "selecting_date" | "selecting_time" | "booking"
    console.log("Selected date:", state.selectedDate);
    console.log("Selected timeslot:", state.selectedTimeslot);
    console.log("Form values:", state.formValues);
  }}
/>

Custom metadata

Pass custom metadata to track booking sources or additional context:

<Booker
  eventSlug="30min"
  username="john"
  metadata={{
    bookingSource: "website",
    userRole: "admin",
    campaignId: "summer-2024",
    referrer: "google-ads"
  }}
/>

Timezone restrictions

Limit available timezones for the booker:

<Booker
  eventSlug="30min"
  username="john"
  timeZones={["Asia/Kolkata", "Europe/London", "America/New_York"]}
/>

Setting the default timezone

By default the booker remembers the last timezone the user selected (persisted in local storage). Pass the timezone prop to control which timezone the booker opens with instead. It takes precedence over the persisted value, and the user can still change it via the timezone selector.

<Booker
  eventSlug="30min"
  username="john"
  timezone="America/New_York"
/>

Handling slot reservation

Monitor slot reservation events:

<Booker
  eventSlug="30min"
  username="john"
  onReserveSlotSuccess={(data) => {
    console.log("Slot reserved:", data);
  }}
  onReserveSlotError={(error) => {
    console.error("Failed to reserve slot:", error);
  }}
  onDeleteSlotSuccess={() => {
    console.log("Slot released");
  }}
  onDeleteSlotError={(error) => {
    console.error("Failed to release slot:", error);
  }}
/>

Custom location URL

Override the default meeting link with a custom URL:

<Booker
  eventSlug="30min"
  username="john"
  locationUrl="https://custom-meeting-platform.com/room/abc123"
/>

Instant meetings

Enable instant meeting mode:

<Booker
  eventSlug="30min"
  username="john"
  isInstantMeeting={true}
  onCreateInstantBookingSuccess={(data) => {
    console.log("Instant meeting created:", data);
  }}
/>

Dry run mode

Test booking flows without creating actual bookings:

<Booker
  eventSlug="30min"
  username="john"
  isBookingDryRun={true}
  onDryRunSuccess={() => {
    console.log("Dry run completed successfully");
  }}
/>

Handling timeslot loading

Execute logic when available timeslots are loaded:

<Booker
  eventSlug="30min"
  username="john"
  onTimeslotsLoaded={(slots) => {
    console.log("Available slots:", slots);
    // slots is a Record<string, Slot[]> where keys are dates
  }}
/>

CRM integration

Integrate with CRM systems for routing and tracking:

<Booker
  eventSlug="30min"
  username="john"
  teamMemberEmail="assigned-rep@company.com"
  crmAppSlug="salesforce"
  crmOwnerRecordType="Lead"
  crmRecordId="00Q5e00000ABC123"
/>

Routing form integration

Pass routing form parameters for advanced routing:

<Booker
  eventSlug="30min"
  username="john"
  routingFormSearchParams="?field1=value1&field2=value2"
/>

Controlling URL parameters

By default, the booker doesn’t update URL parameters in platform mode. Enable this behavior:

<Booker
  eventSlug="30min"
  username="john"
  allowUpdatingUrlParams={true}
/>

Disabling the confirm button

Conditionally disable the booking confirmation button:

const [isProcessing, setIsProcessing] = useState(false);

<Booker
  eventSlug="30min"
  username="john"
  confirmButtonDisabled={isProcessing}
/>

Hiding event metadata

Hide the left sidebar containing event details:

<Booker
  eventSlug="30min"
  username="john"
  hideEventMetadata={true}
/>

When event metadata is hidden, the timezone selector that lives inside the sidebar is also hidden. To keep the timezone selector visible above the booker, pass showTimezoneWhenEventDetailsHidden:

<Booker
  eventSlug="30min"
  username="john"
  hideEventMetadata={true}
  showTimezoneWhenEventDetailsHidden={true}
/>

If the event type has a locked timezone, that timezone is applied automatically and the selector is omitted.

Round robin configuration

For round robin team events, hide organization and team information:

<Booker
  eventSlug="30min"
  isTeamEvent={true}
  teamId={123}
  roundRobinHideOrgAndTeam={true}
/>

Handling calendar failures silently

Display slots even when third-party calendar credentials are invalid:

<Booker
  eventSlug="30min"
  username="john"
  silentlyHandleCalendarFailures={true}
/>

When silentlyHandleCalendarFailures is enabled, the booker may show stale availability if calendar credentials are expired or invalid.

Custom event meta children

Inject custom React components into the event metadata section:

<Booker
  eventSlug="30min"
  username="john"
  eventMetaChildren={
    <div className="custom-meta">
      <p>Custom information here</p>
    </div>
  }
/>

Complete example with all callbacks

import { Booker } from "@calcom/atoms";
import { useState } from "react";

export default function CompleteBookerExample() {
  const [bookingData, setBookingData] = useState(null);

  return (
    <Booker
      eventSlug="30min"
      username="john"
      view="WEEK_VIEW"
      defaultFormValues={{
        firstName: "Jane",
        lastName: "Doe",
        email: "jane@example.com"
      }}
      metadata={{
        source: "website",
        campaign: "summer-2024"
      }}
      onCreateBookingSuccess={(data) => {
        console.log("Booking created:", data);
        setBookingData(data);
      }}
      onCreateBookingError={(error) => {
        console.error("Booking failed:", error);
      }}
      onReserveSlotSuccess={(data) => {
        console.log("Slot reserved:", data);
      }}
      onBookerStateChange={(state) => {
        console.log("Booker state changed:", state);
      }}
      onTimeslotsLoaded={(slots) => {
        console.log("Timeslots loaded:", Object.keys(slots).length, "days");
      }}
      customClassNames={{
        bookerContainer: "rounded-lg shadow-lg",
        datePickerCustomClassNames: {
          datePickerDatesActive: "bg-blue-500"
        }
      }}
    />
  )
}

We offer all kinds of customizations to the booker atom via props and customClassNames.

State management

The Booker atom uses Zustand for internal state management. You can monitor state changes using the onBookerStateChange callback:

Booker states

The booker progresses through several states during the booking flow:

loading - Initial state while event data is being fetched
selecting_date - User is viewing the calendar and selecting a date
selecting_time - User has selected a date and is choosing a time slot
booking - User is filling out the booking form
success - Booking has been successfully created
error - An error occurred during the booking process

Available state values

When using onBookerStateChange, you receive an object containing:

{
  state: BookerState;           // Current state of the booker
  username: string | null;      // Username being booked
  eventSlug: string | null;     // Event type slug
  eventId: number | null;       // Event type ID
  month: string | null;         // Current month (YYYY-MM)
  selectedDate: string | null;  // Selected date (YYYY-MM-DD)
  selectedTimeslot: string | null; // Selected timeslot (ISO string)
  selectedDuration: number | null; // Selected duration in minutes
  formValues: Record<string, any>; // Current form field values
  layout: BookerLayout;         // Current layout (month_view, week_view, column_view)
  timezone: string | null;      // Current timezone
  recurringEventCount: number | null; // Number of recurring events
  // ... and more
}

Example: Tracking booking progress

import { Booker } from "@calcom/atoms";
import { useState } from "react";

export default function TrackedBooker() {
  const [progress, setProgress] = useState({
    hasSelectedDate: false,
    hasSelectedTime: false,
    hasFilledForm: false
  });

  return (
    <Booker
      eventSlug="30min"
      username="john"
      onBookerStateChange={(state) => {
        setProgress({
          hasSelectedDate: !!state.selectedDate,
          hasSelectedTime: !!state.selectedTimeslot,
          hasFilledForm: Object.keys(state.formValues).length > 0
        });
      }}
    />
  )
}

Props reference

Below is a comprehensive list of props that can be passed to the booker atom.

Name	Required	Description
username	Yes	Username of the person whose schedule is to be displayed
eventSlug	Yes	Unique slug created for a particular event
orgBannerUrl	No	URL of the user’s current organization
customClassNames	No	To pass in custom classnames from outside for styling the atom
month	No	The exact month for displaying a user’s availability; defaults to the current month
selectedDate	No	Default selected date for which the slot picker opens
startTime	No	Custom start time for the Booker that allows users to decide the first available date. Accepts JavaScript Date object or date string in format `YYYY-MM-DD` (e.g., `"2025-08-20"` or `new Date("2025-08-20")`)
hideBranding	No	For hiding any branding on the booker
isAway	No	Sets the booker component to the away state
allowsDynamicBooking	No	Boolean indicating if the booking is a dynamic booking
bookingData	No	Data for rescheduling a booking passed in via this prop
defaultFormValues	No	Prefilled values for booking form fields like name, email, guests, notes, reschedule reason, etc.
isTeamEvent	No	Boolean indicating if it is a team event
duration	No	Refers to a multiple-duration event type; selects default if not passed
durationConfig	No	Configures selectable options for a multi-duration event type
hashedLink	No	Refers to the private link from event types page
isInstantMeeting	No	Boolean indicating if the booking is an instant meeting
bookingUid	No	Unique ID generated during booking creation
rescheduleUid	No	Unique ID generated during booking creation, same as bookingUid
locationUrl	No	Custom meeting link URL instead of a Cal.com link
firstName	No	First name of the attendee
lastName	No	Last name of the attendee
guests	No	Invite a guest to join a meeting
name	No	Host name
onCreateBookingSuccess	No	Callback function for successful booking creation
onCreateBookingError	No	Callback function triggered on booking creation failure
onCreateRecurringBookingSuccess	No	Callback function for successful recurring booking creation
onCreateRecurringBookingError	No	Callback function triggered on recurring booking creation failure
onCreateInstantBookingSuccess	No	Callback function for successful instant booking creation
onCreateInstantBookingError	No	Callback function triggered on instant booking creation failure
onReserveSlotSuccess	No	Callback function for successful slot reservation
onReserveSlotError	No	Callback function triggered on slot reservation failure
onDeleteSlotSuccess	No	Callback function for successful slot deletion
onDeleteSlotError	No	Callback function triggered on slot deletion failure
view	No	Specifies the layout of the booker atom into column, week, or month view
metadata	No	Used to pass custom metadata values into the booker. Metadata should be an object eg: `{ bookingSource: "website", userRole: "admin" }`
bannerUrl	No	Adds custom banner to the booker atom
onBookerStateChange	No	Callback function that is triggered when the state of the booker atom changes.
allowUpdatingUrlParams	No	Boolean indicating if the URL parameters should be updated, defaults to false.
confirmButtonDisabled	No	Boolean indicating if the submit button should be disabled, defaults to false.
timeZones	No	Array of valid IANA timezones to be used in the booker. Eg. [“Asia/Kolkata”, “Europe/London”]
timezone	No	IANA timezone the booker opens with (e.g. `"America/New_York"`). Takes precedence over the value persisted in local storage from a previous visit; the booker user can still change it via the timezone selector.
onTimeslotsLoaded	No	Callback function triggered once the available timeslots have been fetched.
roundRobinHideOrgAndTeam	No	Boolean indicating if the organization and team should be hidden in the booker atom sidebar for round robin scheduling type, defaults to false.
showNoAvailabilityDialog	No	Boolean indicating if the no availability dialog should be shown, defaults to true.
silentlyHandleCalendarFailures	No	Boolean when true the booker still displays slots when the third party calendars credentials are invalid or expired, Booker may show stale availability when enabled
hideEventMetadata	No	Boolean that controls the visibility of the event metadata sidebar. When `true`, hides the left sidebar containing event details like title, description, duration, and host information. Defaults to `false`.
showTimezoneWhenEventDetailsHidden	No	Boolean that surfaces a timezone selector row above the booker when `hideEventMetadata` is `true`. Lets attendees change their timezone even when the event details sidebar is hidden. Has no effect when `hideEventMetadata` is `false` or when the event type has a locked timezone. Defaults to `false`.
teamId	Conditional	Required when `isTeamEvent` is `true`. The numeric ID of the team whose event is being booked.
routingFormSearchParams	No	Search parameters from routing forms to pass context for advanced routing logic. Format: `"?field1=value1&field2=value2"`.
teamMemberEmail	No	Email of a specific team member to route the booking to. Used in CRM integrations and team routing.
crmAppSlug	No	Slug of the CRM app being used (e.g., `"salesforce"`, `"hubspot"`). Used for CRM-based routing.
crmOwnerRecordType	No	Type of CRM record being referenced (e.g., `"Lead"`, `"Contact"`). Used with CRM integrations.
crmRecordId	No	Unique identifier of the CRM record. Used to associate bookings with CRM records.
preventEventTypeRedirect	No	Boolean to prevent automatic redirect to event type’s success redirect URL. Defaults to `false`.
handleCreateBooking	No	Custom function to handle booking creation. Overrides the default booking creation logic.
onDryRunSuccess	No	Callback function triggered when a dry run booking completes successfully.
handleSlotReservation	No	Custom function to handle slot reservation logic. Receives the timeslot string as parameter.
entity	No	Entity configuration object containing `orgSlug`, `teamSlug`, `name`, and `considerUnpublished` properties.
eventMetaChildren	No	React node to inject custom content into the event metadata section.
defaultPhoneCountry	No	Sets the default country code for phone number inputs in the booking form. Accepts ISO 3166-1 alpha-2 country codes (e.g., `"us"`, `"gb"`, `"in"`, `"ee"`). When set, phone inputs will default to the specified country’s dialing code.

Styling

Booker atom accepts custom styles via the customClassNames prop. This prop is an object that contains root level styles and nested objects for styling different parts of the booker component. Each nested object groups related styles for a specific section of the booker (e.g., eventMeta, datePicker, availableTimeSlots, etc). Here is an example booker with root level style bookerContainer and nested object datePickerCustomClassNames with datePickerDatesActive style:

import { Booker } from "@calcom/atoms";

export default function Booker( props : BookerProps ) {
  return (
    <>
      <Booker
        ...
        customClassNames={{
          bookerContainer: "bg-[#F5F2FE]! [&_button:!rounded-full] border-subtle border",
          datePickerCustomClassNames: {
            datePickerDatesActive: "bg-[#D7CEF5]!",
          },
        }}
      />
    </>
  )
}

Below is a list of customClassNames properties grouped by their parent objects:

Root Level Styles

Property	Description
bookerContainer	Adds styling to the whole of the booker atom

Event Meta Styles (`eventMetaCustomClassNames`)

Property	Description
eventMetaContainer	Styles the event meta component containing details about an event
eventMetaTitle	Adds styles to the event meta title
eventMetaTimezoneSelect	Adds styles to the event meta timezone selector

Date Picker Styles (`datePickerCustomClassNames`)

Property	Description
datePickerContainer	Adds styling to the date picker
datePickerTitle	Styles the date picker title
datePickerDays	Adds styling to all days in the date picker
datePickerDate	Adds styling to all dates in the date picker
datePickerDatesActive	Styles only the dates with available slots
datePickerToggle	Styles the left and right toggle buttons

Available Time Slots Styles (`availableTimeSlotsCustomClassNames`)

Property	Description
availableTimeSlotsContainer	Adds styling to the available time slots component
availableTimeSlotsHeaderContainer	Styles only the header container
availableTimeSlotsTitle	Adds styles to the title
availableTimeSlotsTimeFormatToggle	Adds styles to the format toggle buttons
availableTimes	Styles all the available times container

Confirmation Step Styles (`confirmStep`)

Property	Description
confirmButton	Styles the confirm button in the booking form
backButton	Styles the back button in the booking form

Here is an example with more custom styles:

import { Booker } from "@calcom/atoms";

export default function Booker( props : BookerProps ) {
  return (
    <>
      <Booker
        ...
        customClassNames={{
          bookerContainer: "bg-[#F5F2FE]! [&_button:!rounded-full] border-subtle border",
          datePickerCustomClassNames: {
            datePickerDatesActive: "bg-[#D7CEF5]!",
          },
          eventMetaCustomClassNames: {
            eventMetaTitle: "text-[#7151DC]",
          },
          availableTimeSlotsCustomClassNames: {
            availableTimeSlotsHeaderContainer: "bg-[#F5F2FE]!",
            availableTimes: "bg-[#D7CEF5]!",
          },
          confirmStep: {
            confirmButton: "bg-purple-700!",
            backButton: "text-purple-700 hover:bg-purple-700! hover:text-white!"
          }
        }}
      />
    </>
  )
}

Rescheduling a booking

The booker atom also supports rescheduling a booking. To reschedule a booking, you need to pass in the rescheduleUid prop to the booker atom along with the other necessary props. This will allow the booker to display the reschedule form and handle the rescheduling process. The rescheduleUid is the booking uid you get when you create a booking.

Host busy slot indicators

When a host reschedules their own booking while logged in, the booker displays all available time slots including ones that overlap with existing calendar events. To help the host make an informed decision, each slot shows a color-coded indicator:

Green dot — the slot is free on the host’s calendar
Red dot — the slot conflicts with an existing event on the host’s calendar

This allows hosts to intentionally double-book when needed, such as when rearranging a low-priority meeting. Guests rescheduling the same booking only see genuinely available slots and do not have the ability to override busy times.

For team events, the host can still see their own busy slot indicators, but other team members’ availability constraints remain enforced. This means the host can override only their own calendar conflicts, not those of other assigned hosts.

Here is an example of how to use the booker atom for rescheduling an individual event:

import { Booker } from "@calcom/atoms";

export default function Booker( props : BookerProps ) {
  return (
    <>
      <Booker
        eventSlug={props.eventTypeSlug}
        username={props.calUsername}
        // rescheduleUid is the booking uid you get when you create a booking
        // it is only required when rescheduling a booking
        rescheduleUid={props.rescheduleUid}
        onCreateBookingSuccess={() => {
          console.log("Booking rescheduled successfully!");
         }}
      />
    </>
  )
}

For team events, you need to pass isTeamEvent and teamId prop to the booker along with the other necessary props. This will allow the booker to display the reschedule form and handle the rescheduling process. The teamId is the team id you get when you create a team event. Here is an example of how to use the booker atom for rescheduling a team event:

import { Booker } from "@calcom/atoms";

export default function Booker( props : BookerProps ) {
  return (
    <>
      <Booker
        eventSlug={props.eventTypeSlug}
        // rescheduleUid is the booking uid you get when you create a booking
        // it is only required when rescheduling a booking
        rescheduleUid={props.rescheduleUid}
        isTeamEvent={true}
        teamId={props.teamId}
        onCreateBookingSuccess={() => {
          console.log("Booking rescheduled successfully!");
         }}
      />
    </>
  )
}

​Basic usage

​Team events

​Dynamic bookings

​Advanced usage patterns

​Prefilling booking form data

​Rescheduling bookings

​Custom start time

​Handling booking state changes

​Custom metadata

​Timezone restrictions

​Setting the default timezone

​Handling slot reservation

​Custom location URL

​Instant meetings

​Dry run mode

​Handling timeslot loading

​CRM integration

​Routing form integration

​Controlling URL parameters

​Disabling the confirm button

​Hiding event metadata

​Round robin configuration

​Handling calendar failures silently

​Custom event meta children

​Complete example with all callbacks

​State management

​Booker states

​Available state values

​Example: Tracking booking progress

​Props reference

​Styling

​Root Level Styles

​Event Meta Styles (eventMetaCustomClassNames)

​Date Picker Styles (datePickerCustomClassNames)

​Available Time Slots Styles (availableTimeSlotsCustomClassNames)

​Confirmation Step Styles (confirmStep)

​Rescheduling a booking

​Host busy slot indicators

Basic usage

Team events

Dynamic bookings

Advanced usage patterns

Prefilling booking form data

Rescheduling bookings

Custom start time

Handling booking state changes

Custom metadata

Timezone restrictions

Setting the default timezone

Handling slot reservation

Custom location URL

Instant meetings

Dry run mode

Handling timeslot loading

CRM integration

Routing form integration

Controlling URL parameters

Disabling the confirm button

Hiding event metadata

Round robin configuration

Handling calendar failures silently

Custom event meta children

Complete example with all callbacks

State management

Booker states

Available state values

Example: Tracking booking progress

Props reference

Styling

Root Level Styles

Event Meta Styles (`eventMetaCustomClassNames`)

Date Picker Styles (`datePickerCustomClassNames`)

Available Time Slots Styles (`availableTimeSlotsCustomClassNames`)

Confirmation Step Styles (`confirmStep`)

Rescheduling a booking

Host busy slot indicators