In FreeClimb, a connection between two or more calls is represented by the Conference instance. Conferences are useful when you want to use FreeClimb to connect:

  • Inbound calls with outbound calls
  • Two or more inbound calls
  • Two or more outbound calls

Inbound calls are those that are received and handled by FreeClimb, while outbound calls are those initiated by FreeClimb to the recipient.


Trial accounts can only make outbound calls to verified numbers.

Creating conferences

You must create conferences explicitly; FreeClimb does not automatically connect two calls. There are two ways to create a conference:

Once created, you can add users to the conference. The conference will persist (and can therefore be used) until you explicitly terminate it.

Working with conferences using the API

You can create a new conference using the FreeClimb API by making a call to the /conferences endpoint. This will create an empty conference to which participants can be added.

Whenever FreeClimb successfully creates a conference, it will also invoke the conference instance’s statusCallbackURL so that your FreeClimb application knows that there exists an empty conference ready for use.

Once a participant joins the conference, the conference’s status changes from empty to populated. At this point, commands such as Say and Play become available, and wait music will start to play (and continue until the actual conference begins).

Conferences can be started (the status changes from populated to inProgress) by any participant who has their startConfOnEnter flag set. If, when creating the conference, you set the conference to be recorded, the recording starts as soon as the conference starts.

At the end, the conference’s status chances from inProgress back to empty as soon as the last participant leaves. If the conference was being recorded, the recording ends at this point as well.

Remember that a conference can be reused as long as its status stays empty. However, if you make a call to the API asking that the conference be set as terminated, FreeClimb removes any remaining participants (the command works regardless of whether the conference is populated or empty), then changes the conference’s status to terminated.

Working with conferences using PerCL

The CreateConference PerCL command creates a new conference that participants can join. Immediately after creation, FreeClimb invokes statusCallbackUrl and actionUrl:

  • statusCallbackURL lets your FreeClimb application knows that there exists an empty conference ready for use
  • actionUrl will return a PerCL script that contains instructions on how to handle the telephone calls that are involved with the conference

The statusCallbackURL is also useful for knowing the various states of your conference:

  • empty: indicates a ready-to-use conference. Can be newly-created or reflects the removal of the last participant after the conference ends.
  • populated: when a conference contains one or more participants
  • inProgress: when a participant who has their startConfOnEnter flag set joins the conference

A conference can be reused as long as its status stays empty, so if you want to end the conference fully, you can do so by executing the TerminateConference command. FreeClimb will remove all participants, ending the calls.

Webhooks for conferences

For more information on the Webhooks used in the creation and management of Conferences, see Conferences.

Ready to try conferencing with FreeClimb?

Explore the Conferences API Reference.

Try one of our conferencing code snippet how-to guides: