backchannel
Release v0.2.4

Clearer speaker turns with a lighter local path

Backchannel v0.2.4 improves two-speaker separation inside long mixed turns, makes local Whisper and Parakeet models work on first use without an API key, and removes avoidable lightweight-runtime overhead.

Download Read quickstart GitHub release

Download Backchannel v0.2.4

These unsigned open-source builds are delivered through the authenticated Backchannel portal. An approved Backchannel account is required; no GitHub identity or repository membership is required. The first run includes the normal Windows SmartScreen or macOS Gatekeeper prompts.

Windows

Windows x64

For Windows 10 or later on 64-bit Intel or AMD processors.

  1. Download Backchannel-windows-x64-v0.2.4.zip.
  2. Unzip it and run Backchannel.exe.
  3. If SmartScreen appears, choose More info, then Run anyway.
Open v0.2.4 downloads
macOS

macOS Apple Silicon

For Apple Silicon Macs. Intel macOS builds are not included in this release.

  1. Download Backchannel-macos-arm64-v0.2.4.zip.
  2. Unzip it and move Backchannel.app wherever you keep apps.
  3. Right-click Backchannel.app and choose Open the first time.
Open v0.2.4 downloads
Linux

Linux x64

A portable bundle for 64-bit Intel or AMD Linux systems.

  1. Download Backchannel-linux-x64-v0.2.4.tar.gz.
  2. Extract it with tar -xzf Backchannel-linux-x64-v0.2.4.tar.gz.
  3. Run Backchannel/Backchannel.
Open v0.2.4 downloads

What changed

This patch release improves the default local audio path without changing the established speaker-similarity threshold.

Mixed-turn coherence

Long unmatched turns are checked in short windows and split only when adjacent voice embeddings lose coherence. Ambiguous groups reuse existing profiles instead of creating extra speakers.

Local ASR first use

Whisper and Parakeet models can download on first use without an API key, then reuse their local cache when the machine is offline.

Lighter startup

Normal live calls and audio imports using lightweight diarization skip optional Sortformer probes, and the backend starts without an extra wrapper process.

First-run notes

NeedWhat to do
Release access Use the email and password for your approved Backchannel recipient account.
Provider key Add a Gemini key in Admin -> API Keys after launch. Add OpenAI only if you route agents to OpenAI.
Speaker labels During split-track capture, the physical microphone maps to the sole local user. Voices from a shared tab or system source remain remote speaker clusters.
Upgrading Quit the old version from the tray before starting the new one. Session data is stored per-user and is shared by every version.
Desktop launch Backchannel opens a browser at a local localhost address and remains available from the system tray or menu bar.
Docker Check out the v0.2.4 source tag and rebuild Compose to run the same release through containers.

Start with the desktop app or self-host the stack

Both paths run Backchannel on your machine. Choose the desktop bundle for the fastest start, or Compose for maximum control.

Download v0.2.4 Compare setup paths View source