Mos

Mos is a free, source-available macOS menu-bar utility for making mouse-wheel scrolling smoother and configuring scrolling and mouse-button behavior. It reshapes wheel events locally and lets individual applications use different settings. It is useful when a conventional mouse feels abrupt compared with a trackpad.

Main features

• Adjust wheel smoothing with step, speed and animation-duration controls.
• Configure horizontal and vertical smoothing and reversal independently.
• Customize mouse scrolling while retaining separate trackpad behavior.
• Apply per-application profiles or inherit global settings.
• Bind mouse buttons and custom keys to shortcuts, system actions or recorded events.
• Use supported Logitech HID++ buttons through Bolt, Unifying or direct Bluetooth connections.

Button actions can also open applications, files or configured scripts. Hardware-specific behavior depends on the device and connection; native HID++ support does not guarantee every Logitech model or proprietary event is supported.

Install and configure

Install with brew install --cask mos, or download the official release ZIP and move Mos.app into Applications. Launch the installed copy and use its menu-bar controls to configure smoothing, direction and application profiles. Enable macOS Accessibility access for Mos when prompted: the application needs this authorization to handle input events. This is local input handling, not a remote-control account service.

If an update or moved application leaves a stale authorization entry, the official troubleshooting wiki explains how to quit Mos, remove its old entry in Privacy & Security → Accessibility, then add and enable the installed /Applications/Mos.app again. Follow that guidance if needed; installing this catalog package does not itself grant permissions.

Requirements and compatibility

The current official 4.2.1 ZIP contains a universal executable for Intel x86-64 and Apple Silicon ARM64. Its application metadata requires macOS 10.13; binary inspection shows an Intel deployment target of 10.13 and an ARM target of 11.0. Use macOS 11 or later on Apple Silicon. The current cask declares no explicit macOS minimum or formula dependency and conflicts with mos@beta. Mos is a macOS utility; the reviewed sources do not offer Windows or Linux equivalents.

The verified ZIP is 12,127,893 bytes and its SHA-256 matches the recorded Homebrew cask. Its application version is 4.2.1 and build is 20260531.1. These are the version and installer-build parts of the same recorded release, not two distinct feature versions. Download size is not installed disk space. No universal RAM or installed-space requirement was established.

Applications and other mouse-event utilities may interpret or modify scrolling differently. Use application overrides and temporarily disable overlapping smoothing or remapping while diagnosing unexpected behavior. This is an operational compatibility consideration, not an additional declared Homebrew package conflict. Do not assume smoother input changes an application's underlying scrolling implementation.

Accounts, privacy and cost

Mos processes scrolling and button behavior locally and does not require a hosted account or subscription for these functions. Downloads and source hosting use GitHub. The developer's privacy page distinguishes the local application from the website, which uses Google Analytics for website statistics; it does not claim that granting Accessibility creates a remote-control channel. Review the source when exact implementation or configuration-storage behavior matters.

Mos is free to download and the project accepts optional donations. The tagged repository is licensed under Creative Commons Attribution-NonCommercial 4.0. The published license permits sharing and adaptation subject to attribution and noncommercial conditions. It must not be described as an unrestricted commercial software license. For a proposed commercial use or redistribution, review the actual license and obtain any additional permission needed from the rights holder; no paid commercial-license tier was established in the reviewed sources.

The accompanying official, tagged Mac illustration shows the per-application profile editor. It is an official product illustration published with the 4.2.1 source.

Sources: Official project, Tagged source and feature guide, Release 4.2.1, Permissions troubleshooting, Privacy notes, Tagged license.