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AI Frontdesk: Setting up appointment booking with Cal.com or Calendly

Valid for: AI Receptionist (packages from August 19, 2026) and AI Chat Assistant (Momentum AI)

Once you have integrated your booking tool, your assistant will check the available slots in your calendar during the call and book appointments directly for your customers. You can connect Cal.com and Calendly using an API key, which you can create in your account with the respective provider; you then specify which appointments the assistant is authorised to book. This feature is available with the AI Chat Assistant and the AI Receptionist; please see Requirements to find out which products and packages include it. The following steps show you how to set up the connection.

Requirements

  • You must meet one of the following two conditions:
    • AI Chat Assistant – on its own or in addition to an AI Receptionist contract, regardless of the package.
    • AI Receptionist on the Flex Pro or Unlimited package.
  • You have an active user account with Cal.com or Calendly.

Open the assistant’s settings

  • Log in to your IONOS account.
  • Click on Menu > AI Frontdesk in the title bar.
  • In the contract overview, click on Manage in the tile for the contract you want.
  • In the navigation on the left, under Settings, click on Appointment Booking. The section of the same name expands on the Configure assistant page. This is where you configure all the following settings.

Note

Your assistants share these settings: if you have ordered more than one of the products listed under Valid for above for your contract, the details you enter here apply to all of them.

Select a booking tool

  • In the Appointment Booking section, first select your booking tool.

  • Under Other providers, click on Cal.com or Calendly.

Note

Only one booking tool can be linked to each assistant at any one time. To switch to a different one, first remove the linked tool.

Establish a connection using an API key

In order for the assistant to be able to book appointments on your behalf, it needs access to your calendar. You grant it this access via an API key – also known as a personal access token on Calendly – which you will create and save below.

Please Note

The API key grants access to your calendar functions. You should therefore treat it as confidentially as you would a password and not share it with unauthorised persons. Should the key ever be compromised, you can delete it at any time from your Cal.com or Calendly account and create a new one.

  • Click on the Create API key link. The API settings for your account with the selected booking tool will open in a new browser tab.
  • Log in with your credentials if you are not already logged in.
  • Create the API key and copy it to the clipboard:
    • Cal.com: Create a new API key in the developer settings; you’ll need a v2 key. Further information can be found in the Cal.com documentation.
    • Calendly: Click on Generate new token – or Get a token now when creating one for the first time – and follow the steps. The token generated is your API key. Depending on your version of Calendly, the menu navigation may vary; you can find up-to-date and detailed instructions in the Calendly documentation.
  • Return to the assistant interface and enter the key in the API Key field. The system checks the entry immediately; if successful, a green tick appears in the field on the left. The key is then displayed as hidden – click the eye icon on the right-hand side of the field to show it again.

Select the types of appointment that can be booked

You create your appointment types in Cal.com or Calendly; in the assistant interface, you simply select which of these the assistant is permitted to use.

Under Available appointment types, select all the appointment types that the assistant is permitted to book for you – you can select several. Each entry in the list shows the name and duration of the appointment type, as stored in your booking tool.

Notes

  • Are your appointment types not showing up? First, make sure they have been created in Cal.com or Calendly. Then refresh the page.
  • When booking appointments with Cal.com and Calendly, the time zone you set in the Assistant & Language settings section applies – if you’ve ordered AI Receptionist, this section is called Language, Voice & Behavior. Check that your company’s time zone is set there to ensure appointments are booked at the correct time – see AI Frontdesk: Customising language, voice, and behaviour.

Remove connection

At the very bottom of the Appointment Booking section is the Remove integration button. This allows you to disconnect the linked booking tool from the assistant interface – which is necessary, for example, if you wish to link a different booking tool instead.

Save changes

To apply your changes, click the Save button in the top right-hand corner. As long as you have not made any changes, the button is greyed out.

Note on hallucinations

AI systems may occasionally make incorrect or inaccurate statements, known as hallucinations. This means that the AI estimates or interprets answers when no clear information is available.

Please Note:

  • The AI cannot always adhere 100% to your specifications.
  • You should therefore scrutinise important answers carefully.
  • Such deviations are not technical faults, but a typical characteristic of generative AI.

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