Switchboard

한국어

Connect a voice agent from your app of choice to the macOS Phone app. Listen to both sides, adjust their volumes independently, and record the conversation.

Verified with gpt-live-1 on ChatGPT Desktop or Web. I personally recommend it.

Demo

Switchboard-Demo.mp4

Recorded-call replay with Korean subtitles.

Features

• Select the Agent and calling applications.
• Start, pause, resume, and save named sessions.
• Control recording and transcription independently.
• Separate caller and Agent waveforms and listening levels.
• Live transcripts with translations beneath the original text.
• Context-aware translation and saved-recording transcription and translation.
• Recording playback, search, and timestamp navigation.
• Recording dates and missing-audio interval details.
• Complete session-file export, including audio and conversation text.
• M4A, separate-source WAV, and transcript TXT exports.
• Headphone monitoring with optional built-in speaker fallback.
• English and Korean interfaces that follow macOS text and appearance settings.
• VoiceOver, keyboard navigation, non-color status cues, and macOS contrast, motion, and transparency preferences.

Requirements

• Apple Silicon Mac running macOS 26 or later.
• Swift 6.2 or later and macOS SDK 26 or later.
• Python 3.
• A calling app with selectable microphone and speaker devices.

Transcription and translation languages depend on the models available on your Mac. Download missing models from the language controls in the session.

On macOS 26.4 and later, translation uses recent conversation context. As new speech arrives, recent translations may update to reflect that context. The original text, speaker, and timestamps stay attached to each entry. Earlier supported macOS versions translate entries individually.

Install a downloaded release

Download the app ZIP from Releases, unzip it, and move Switchboard.app to Applications.

The app is ad-hoc signed and does not have a Developer ID signature or Apple notarization. If macOS blocks it, try opening it once, then choose System Settings → Privacy & Security → Open Anyway and confirm Open.

For a download from this repository that you trust, you can also remove this app's quarantine attribute in Terminal and open it:

xattr -dr com.apple.quarantine "/Applications/Switchboard.app"
open "/Applications/Switchboard.app"

If xattr reports Permission denied, retry that command with sudo, then open the app again. See Apple's instructions.

Build

Use Xcode 26.4 or later to include contextual translation. Xcode 26.0.1 builds retain individual-entry translation.

bash scripts/check.sh
bash scripts/build-app.sh release

When building a downloaded source archive, supply a positive build number:

SWITCHBOARD_BUILD_NUMBER=1 bash scripts/build-app.sh release

The app is generated at build/Switchboard.app. To create a DMG:

bash scripts/build-dmg.sh

Connect

1. Open Switchboard and choose a language.
2. Select the Agent and calling apps in Settings.
3. Install the audio devices and allow microphone and system-audio access.
4. Select these devices in the two apps:
   • Agent microphone: Switchboard → Agent
   • Calling app speaker: Caller → Switchboard
   • Calling app microphone: Agent → Caller

If the Agent app only offers Default, leave it selected. Switchboard selects the Mac's input when you start a session.

Choose your listening device, enter a session name, and press Start. Recording begins with the session. Use the recording and transcription controls to change what is captured.

Pause stops the relay, recording, and transcription together. Resume restores your choices. Paused time remains silent in the saved audio.

Choose End Session, then Save to name the session file and choose its location. The library shows the default folder and any folders added in Settings. You can also open a session file directly.

The information button beside each recording shows its start date, duration, and any missing-audio intervals. Interval counts and total missing time are shown separately. Expand a source to inspect positions within the recording.

Use Command-F in the conversation to find original text or translations; in the recording list, it searches recordings. You can change transcript languages during a session and select Start to continue with the new settings.

Text follows the macOS accessibility text-size setting throughout the app.

In Recordings, use Transcribe for a recording made with Record Only. Existing transcripts offer Transcript actions to continue incomplete work, transcribe again, or translate the saved text into another language. Processing can be paused and resumed after restarting the app. Review Current and New result, then choose Apply or Discard. Processing does not change the original audio.

A .switchboard session file is a macOS package containing JSON metadata and its audio and text files. Export session file creates a complete copy of that package. Older .mihrecording files remain readable and export as .switchboard session files.

See installation, architecture, testing, versions, and changelog.