Sign Chat Bridge is a desktop companion that pipes the same Signchat audio graph into a system-level virtual microphone. Open FaceTime, Zoom, Meet, Teams, or Discord, pick the Bridge mic, and your signs become spoken sentences in any 1:1 conversation.
Bridge wraps the same browser pipeline you already use at signchat.org inside an Electron desktop app, then publishes its synthesised voice as a system-level mic. There’s no new backend, no relay, and no per-call setup beyond picking the right device once.
Bridge mixes your synthesised voice into a BlackHole virtual microphone so any video tool that picks a mic can use Signchat — no SDK or extension needed.
Bridge runs the identical OpenRouter and ElevenLabs pipeline as the web app. No new backend, no relay — your sign tokens stitch and stream straight from the desktop renderer.
Pick the Bridge mic in FaceTime, Zoom, Google Meet, Teams, or Discord. Live captions of the call come back through a BlackHole loopback so you read what they say in real time.
Bridge ships as a notarised DMG and walks you through the device picker the first time you launch it. The one-time prerequisites live below.
Apple Silicon (arm64) and Intel (x64) are both supported. Bridge is signed and notarised; double-click the DMG and drag it to Applications.
Bridge plays its synthesised voice into BlackHole 2ch (the virtual mic Zoom subscribes to) and reads the call back through BlackHole 16ch for live captions. Install both from existential.audio/blackhole.
Open Audio MIDI Setup, click + → Create Multi-Output Device, and check both your normal speakers / headphones and BlackHole 16ch. Name it Bridge Loopback. In your video tool, pick that device as the speaker output so Bridge can transcribe what the other side says.
Bridge asks for camera access (to capture your signing for MediaPipe and the ASL classifier) and microphone access (to read the BlackHole loopback). Both are local-only — no audio or video leaves your machine on the per-turn data path.
Bridge is open source, free, and runs entirely on your machine. The latest DMG is on GitHub Releases.
Download Bridge