Companion User Guide

Companion Satellite is a lightweight application that allows physical USB control surfaces (such as Elgato Stream Decks) to be connected to a central Bitfocus Companion server running on a different machine. This enables the distribution of controllers across multiple computers without needing to install the full Companion software on every workstation. Connected surfaces appear in the central Companion instance as if they were locally attached, allowing for standard page and button configuration.

Variables allow for dynamic values within action options, feedback options, and button styles. Variables are supported in any input field marked with the variables support icon.

Expressions are a formula language built into Companion that allows for mathematical calculations, value comparisons, decision-making, and text formatting. This enables the creation of complex behaviors without requiring additional buttons, triggers, or external scripts.

// Example: Countdown to a 19:30 show start
secondsToTimestamp(max(0, timeDiff($(internal:time_hms), '19:30:00')), 'HH:mm:ss')

A surface module in Companion is a plugin that enables communication with physical control hardware. Its primary responsibilities include reading button presses and encoder turns, and rendering button graphics, indicators, and brightness onto the hardware. Surface modules share the same development environment, repository tooling, and release process as connection modules.

Companion Satellite is a lightweight application installed on a separate machine from the main Companion server. It forwards locally connected surfaces (such as Stream Decks) to a central Companion instance over the network. This is primarily used when surfaces are in different rooms, when Companion is running in Docker/on a server without direct USB access, or when multiple operators need their own hardware controlled by one setup.

Bitfocus Companion is a free, open-source software tool designed to control a wide variety of professional AV and production hardware. It supports over 700 different types of devices, including mixers, switchers, lighting controllers, and streaming gear.

Expressions are a built-in formula language in Companion that allows for mathematical calculations, value comparisons, decision-making, and text formatting. They enable complex behavior without requiring additional buttons, triggers, or external scripts.

// Example: Countdown to 19:30 show start
secondsToTimestamp(max(0, timeDiff($(internal:time_hms), '19:30:00')), 'HH:mm:ss')

Variables allow for dynamic values in action options, feedback options, button styles, and other input fields. A field supports variables if it displays the variables support icon. Variables are managed via the variables page in the Companion UI.

Companion is a free, open-source, brand-agnostic control surface software that allows users to control an extensive range of equipment (presentation switchers, broadcast equipment, video playback software, and home automation) using professional control surfaces. While it is designed to elevate devices like the Elgato Stream Deck, it does not require physical hardware to function.

Variables allow for dynamic values within action options, feedback options, and button styles. Variables can be used in any input field marked with the variables support icon.

The expression editor input field has been rebuilt to function like a code editor. It now supports functions and keyword suggestions, as well as improved handling of multi-line expressions.

The Companion Admin interface (v4.3) consists of three primary areas: a left Sidebar for page navigation, a top Header for notifications and support access, and a main content area. The main area is typically split into a large main panel (left) for primary tasks and a secondary panel (right) for details, previews, or contextual settings. On smaller screens, these panels are combined to reduce scrolling.