Caster Soundboard

A modern, touch-first soundboard designed for podcasters, live streamers, broadcasters, and tabletop gamers.

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Overview

Caster Soundboard is a fast, tactile audio playback tool engineered for live broadcast environments. Built with a high-performance C++ engine and a fluid Qt 6 / QML touch interface, Caster Soundboard allows you to trigger clips, jingles, sound effects, and background music loops instantly.

It features integrated virtual microphone audio routing, enabling you to pipe your voice and soundboard clips directly into VoIP applications like Discord, OBS Studio, Zoom, and Twitch without needing external mixer hardware or messy patch cables.

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Screenshots

Main Soundboard Grid

Fluid multi-tab sound banks with real-time waveform progress, dedicated volume sliders, looping badges, and customizable hotkey indicators.

Push-to-Talk (PTT) & Mic Automation

Kernel-level /dev/uinput virtual keyboard automation that automatically keys up Discord, OBS, or games during sound playback with configurable pre/post delay buffers.

Tile Settings & Waveform Cue Trimming

Non-destructive intro/outro cue trimming with interactive drag handles, real-time waveform scrubbing, color theming, and playback trigger modes.

Virtual Audio Routing & Signal Flow

Interactive orthogonal circuit diagram visualizing your physical mic, soundboard audio mix node, virtual microphone endpoints, and monitor output.

Touch-Friendly Web Remote Surface

Responsive local HTTP/SSE control surface for triggering sounds, panic-stopping, and ducking audio from any phone, tablet, or browser on your local network.

Interactive Documentation & CLI Guide

Comprehensive in-app guide covering CLI automation flags, global keyboard shortcut scopes, OSC endpoints, and MCP AI integration.

Preferences & Workspace Settings

Ducking attenuation controls, sound tile hotkey scoping (Bank Mode vs. Global Mode), emergency shortcuts, and background server settings.

About & System Diagnostics

Real-time project persistence tracking, audio subsystem health, system diagnostics, and community issue reporting.

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Key Features

• Touch-First Grid Interface: Resizable tile grid with pinch/slider zoom, horizontal & vertical touch scrolling, and seamless file drag-and-drop.
• Virtual Microphone (PipeWire / PulseAudio): Merges your hardware microphone with soundboard clips into a first-class virtual audio input recognized by Discord, OBS, Zoom, and WebRTC browsers.
• Waveform Sweeper & Cue Editing: Visual audio waveform rendering with dual interactive drag handles for non-destructive intro/outro cue trimming and loop playback.
• Sound Banks & Flexible Hotkeys: Support for multiple tabs with customizable hotkey scopes (Bank Mode to reuse keys across tabs, or Global Mode to trigger sounds anywhere).
• Push-to-Talk (PTT) & Mic Automation: Kernel-level /dev/uinput virtual keyboard automation that automatically keys up Discord, OBS, or in-game PTT (or toggles mic mute) during sound playback with customizable pre/post delay buffers.
• Audio Ducking: Automatically attenuates soundboard playback volume with assignable shortcuts (Ctrl+D) so host commentary cuts through cleanly.
• Panic Button: Instant stop-all shortcut (Space) to silence all active audio channels immediately and release any active PTT transmissions.
• Web Remote Control Surface: Built-in HTTP server (port 5052) providing a touch-friendly web remote accessible from any smartphone, tablet, or secondary display on your local network.
• Model Context Protocol (MCP): Native JSON-RPC 2.0 MCP server (port 5055 / stdio) allowing AI assistants (Claude Desktop, Antigravity, Cursor) to inspect soundboard state, trigger clips, manage live audio ducking, and adjust volumes.
• Open Sound Control (OSC): Two-way OSC UDP server (port 8000) compatible with TouchOSC (includes bundled layouts in TouchOSC-Layouts/).
• Headless Mode: Run as a low-overhead background audio server on dedicated studio machines using --headless.

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Installation & Distribution

Caster Soundboard supports multiple universal Linux packaging formats:

1. AppImage (Standalone Portable)

No installation required. Download the pre-built .AppImage from GitHub Releases, make it executable, and run:

chmod +x CasterSoundboard-*-x86_64.AppImage
./CasterSoundboard-*-x86_64.AppImage

To compile a standalone AppImage locally:

./scripts/build-appimage.sh

2. Flatpak (Universal Linux)

Download the .flatpak bundle from GitHub Releases:

flatpak install --user CasterSoundboard-*-x86_64.flatpak
flatpak run io.github.covarianttensor.CasterSoundboard

Or build from source using flatpak-builder:

./scripts/build-flatpak.sh

3. Debian / Ubuntu (.deb & PPA)

Option A: Ubuntu PPA (Automatic updates on Ubuntu 24.04 LTS+)

sudo add-apt-repository ppa:covarianttensor/castersoundboard
sudo apt update
sudo apt install castersoundboard

Option B: Standalone .deb Package

Download the pre-built .deb package from GitHub Releases and install via apt:

sudo apt install ./castersoundboard_*.deb

To compile and package a .deb locally with CPack:

./scripts/build-deb.sh

4. Fedora / RHEL / openSUSE (.rpm & COPR)

Option A: Fedora COPR (Automatic updates on Fedora 40+)

sudo dnf copr enable covarianttensor/castersoundboard
sudo dnf install castersoundboard

Option B: Standalone .rpm Package

Download the pre-built .rpm package from GitHub Releases and install via dnf or zypper:

# Fedora / RHEL
sudo dnf install ./castersoundboard-*.rpm

# openSUSE
sudo zypper install ./castersoundboard-*.rpm

To compile and package an .rpm or Source RPM (.src.rpm) locally:

./scripts/build-rpm.sh
./scripts/build-srpm.sh

5. Snap (Universal Linux / Ubuntu App Center)

Download the pre-built .snap package from GitHub Releases and install via snap:

sudo snap install --dangerous castersoundboard_*.snap

To compile a Snap package locally with Snapcraft:

./scripts/build-snap.sh

6. Arch Linux / Manjaro / CachyOS (.pkg.tar.zst)

Option A: Pre-built Native Package

Download the pre-built .pkg.tar.zst package from GitHub Releases and install via pacman:

sudo pacman -U castersoundboard-*.pkg.tar.zst

Option B: Build and install locally

./scripts/build-arch.sh
sudo pacman -U castersoundboard-*.pkg.tar.zst

Or build via dist/aur/PKGBUILD:

cd dist/aur
makepkg -si

7. Void Linux (XBPS)

Option A: Pre-built Native Package

Download the pre-built .xbps package (castersoundboard-*.xbps) from GitHub Releases.

Using xbps-rindex (Standard):

# Index the directory containing the downloaded package:
xbps-rindex -a castersoundboard-*.xbps

# Install from the local directory repository:
sudo xbps-install -R . castersoundboard

Or using xdowngrade (from xtools):

sudo xdowngrade castersoundboard-*.xbps

Option B: Build via xbps-src

# Automated local build:
./scripts/build-void.sh
xbps-rindex -a castersoundboard-*.xbps
sudo xbps-install -R . castersoundboard

Or using an existing void-packages tree:

# 1. Copy the template into your void-packages clone:
mkdir -p srcpkgs/castersoundboard
cp dist/void/template srcpkgs/castersoundboard/

# 2. Build the binary package:
./xbps-src pkg castersoundboard

# 3. Install the generated package:
sudo xbps-install -R hostdir/binpkgs castersoundboard
# Or using the xbps-src shortcut:
./xbps-src xi castersoundboard

8. NixOS / Nix Flakes

Run directly via Nix Flakes:

nix run github:covarianttensor/CasterSoundboard

Or build locally with default.nix:

nix-build
./result/bin/CasterSoundboard

9. Native Build from Source (CMake)

Build and install natively on any Linux distribution (Ubuntu, Debian, Fedora, Arch):

Prerequisites

• C++17 compiler (GCC 9+ or Clang 10+)
• CMake 3.16+
• Qt 6.5+ (qt6-base, qt6-declarative, qt6-quickcontrols2, qt6-multimedia, qt6-network)
• FFmpeg (for waveform extraction and multi-codec playback)
• PulseAudio / PipeWire (pulseaudio-utils)

# Clone the repository
git clone https://github.com/covarianttensor/CasterSoundboard.git
cd CasterSoundboard

# Configure and compile
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j$(nproc)

# Run tests
ctest --test-dir build --output-on-failure

# Install to system (optional)
sudo cmake --install build

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Command Line Usage

CasterSoundboard [options] [project.caster]

Option	Description
[project.caster]	Load a specific .caster project file on launch.
-f, --fullscreen	Launch application directly in fullscreen mode (toggle with F11).
--window-width <px>	Set initial window width in pixels (minimum: 640).
--window-height <px>	Set initial window height in pixels (minimum: 480).
--headless	Run without a graphical window (ideal for studio servers and OSC/Web controllers).
--auto-start-web	Automatically start the Web Remote server on launch.
--web-port <port>	Specify custom TCP port for Web Remote (default: 5052).
--web-user <user>	Username for Web Remote authentication (default: caster).
--web-pass <pass>	Password for Web Remote authentication (default: caster).
--auto-start-mcp	Automatically start the Model Context Protocol (MCP) server on launch.
--mcp-port <port>	Specify custom TCP port for MCP server (default: 5055).
--mcp-stdio	Run MCP server directly over standard I/O (stdio) in headless mode.
--auto-start-osc	Automatically start the UDP Open Sound Control (OSC) server.
--view <0-5>	Start directly on a specific view (0: Soundboard, 1: Audio Devices, 2: OSC, 3: Settings, 4: Docs, 5: About).
-s, --screenshot <path>	Capture high-resolution window screenshot to path and exit immediately.

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Remote Control & AI Automation

Caster Soundboard provides three distinct integration protocols for touch surfaces, studio controllers, and AI assistants:

1. Web Remote (Touch Surface)

Open http://<your-computer-ip>:5052 in any web browser on your smartphone, tablet (iPad/Android), or laptop on your local network.

• Real-Time Sync: Server-Sent Events (SSE) provide live status feedback with glowing halos for playing tiles.
• Studio Controls: Dedicated Panic Stop All button, audio ducking toggle, and tab switching.
• Security: Protected with HTTP Basic authentication (default: caster / caster).

2. TouchOSC & Open Sound Control (OSC)

Connect your tablet or modular studio controller (TouchOSC, Bitfocus Companion, QLab, Stream Deck) to UDP port 8000. Bundled layouts are available in TouchOSC-Layouts/.

3. Model Context Protocol (MCP) AI Server

Caster Soundboard embeds a native Model Context Protocol (MCP) server on TCP port 5055 (SSE endpoint /sse, JSON-RPC endpoint /message), along with a zero-dependency Node.js stdio bridge (scripts/caster-mcp.js). AI desktop assistants such as Claude Desktop, Antigravity, or Cursor can query soundboard state and orchestrate live audio.

Claude Desktop Configuration (claude_desktop_config.json)

{
  "mcpServers": {
    "caster": {
      "command": "node",
      "args": ["/absolute/path/to/CasterSoundboard/scripts/caster-mcp.js"]
    }
  }
}

Available Native MCP Tools

Tool	Description
caster_get_state	Full JSON state snapshot of tabs, sound tiles, volume levels, ducking state, and active playback.
caster_trigger_sound	Plays or stops a sound tile by tab/tile index or title search query.
caster_stop_all	Emergency panic stop: silences all active audio channels across all tabs.
caster_set_ducking	Enables or disables audio ducking attenuation for voiceover commentary.
caster_switch_tab	Switches the active sound bank tab by index or tab name.
caster_set_volume	Sets volume for a specific tile or active master tab (0.0 to 1.0).
caster_get_audio_routing	Queries active PipeWire/PulseAudio endpoints and virtual microphone status.

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License

Caster Soundboard is free and open-source software licensed under the GNU Lesser General Public License v3.0 or later (LGPL-3.0-or-later).