API Description

The Calls API can be used to call fixed and mobile telephone numbers and invoke predefined static or dynamic scenarios for this interaction.

The endpoint for this interaction is always the Developer Platform API server. To establish a call between two (or more) parties, the API server will call each party individually and bridge the call legs.

The enabled call scenarios fit in the category of Application-to-Person (A2P) scenarios. Despite this classification being often used for messaging, the calling scenarios are similar: An application queries the API and establishes one or multiple calls to interact with any telephone in the world.

The back channel is not provided, i.e., numbers cannot be called back to interact yet. If certain use cases require this, the preconditions need to be arranged on an individual base.


The usage of the API is only permitted if calling party phone numbers are used that belong to the sender or for which the sender has a right of use. In the future, mechanisms will enforce this, but they have not been implemented yet. Any misuse violates the agreement under which the API is made available and access will need to be revoked.

The API has global reach, but some countries or operators may have been disabled. If you encounter unforeseen issues please get in touch.

Component Overview

An overview of all components is shown in the following figure:


Best carrier network

The API uses Telekom Global Carrier's intercarrier voice platform. High-quality routes between all Deutsche Telekom Group companies and almost every other carrier in the world.

Plug & Play

Easily integrate our Calls API: A single request grants access to Telekom's infrastructure and best connectivity between carriers.

Programmable API

The Telekom Telephony service many customers already rely upon. Now with a modern programmable RESTful API.