Mist is a Mac utility that automatically downloads macOS Firmwares and Installers.
The tool solves the problem of obtaining macOS installation media by querying Apple's Software Update catalogs and automating the download and packaging process. It retrieves available macOS versions from standard, customer seed, developer seed, and public seed catalogs, then generates the appropriate installation artifacts for the user's Mac architecture. For Apple Silicon Macs, it downloads firmware restore files with SHA-1 validation. For Intel-based Macs, it can generate application bundles, disk images, bootable ISO files for virtualization, or installer packages, with optional codesigning support. The tool caches downloads to accelerate subsequent builds and includes automatic retry logic for failed transfers.
Mist suits Mac administrators and users who need to maintain offline installation media or automate macOS deployment workflows. It is particularly valuable for organizations managing multiple Macs or those requiring access to beta versions through Apple's seed programs. The tool's ability to generate multiple output formats—from simple .app bundles to bootable ISOs for virtualization platforms and large installer packages exceeding 12GB—makes it flexible across different deployment scenarios. Users should note that access to seed program catalogs requires membership in the respective Apple programs.
The project maintains active continuous integration with linting, unit tests, and build workflows. Development activity shows consistent attention to code quality and reliability through automated testing infrastructure.
