Connect to OpenAI Realtime
Connect callers directly to OpenAI's Realtime API for natural, low-latency voice AI conversations. Use dial@v1 to bridge calls to OpenAI's SIP endpoint with full call control and recording.
Overview
Callr connects your callers directly to OpenAI's Realtime API through native SIP integration. This enables natural, low-latency voice AI conversations without any intermediate transcription step — audio flows directly between the caller and OpenAI's voice model.
How it works
Use the dial@v1 action to bridge the caller to OpenAI's SIP endpoint. Configure your OpenAI session parameters (model, instructions, voice, tools) and Callr handles the SIP signaling, media transport, and call lifecycle. Combine with startRecording@v1 for compliance recording and fetch@v2 to push conversation results to your systems.
Use cases
Build voice AI agents that handle customer service, appointment scheduling, order taking, and complex multi-turn conversations with human-like responsiveness. Ideal for high-volume call centers looking to automate routine interactions.
Others features
We own our network
Global coverage
Order numbers in just one click in over 220 countries, including premium, vanity or toll-numbers.
Encrypted and secure
We offer state-of-the-art data encryption with HTTPS, SIP TLS & SRTP.
Reliable network
With multiple data centers and servers around the world, we offer a robust service you can rely on.
Registered carrier
We operate our own network for better performance, localization and support.
