Relente is a native Mac app that creates a bootable USB drive from a macOS installer, so you can do a clean install of macOS. It wraps Apple's own createinstallmedia tool in a guided, visual flow: pick an installer, pick a USB drive, review, and create.
It is written in Swift and SwiftUI, and only works with macOS installers and removable drives (USB drives and SD cards). Internal disks and external SSDs or hard drives are never offered as a destination.
Warning
Relente is in early development and will erase the drive you choose. Always double-check the drive before confirming.
- An Apple silicon Mac running macOS 26.0 Tahoe or later. See the support policy.
- A macOS installer from Big Sur (11) onwards, in any of these forms:
Install macOS <name>.app- A
.dmgthat contains the installer app InstallAssistant.pkg
- A USB drive or SD card of at least 16 GB. Everything on it will be erased.
Version 0.11.0 is published. Recorded validation and its limitations are described in release readiness.
To build it yourself, see BUILDING.md.
- Open Relente and approve its system helper when macOS asks. For live USB creation, enable Relente in System Settings → Privacy & Security → Full Disk Access and allow its helper under General → Login Items. You can browse installers and choose a USB before enabling Full Disk Access; Relente checks write access before starting an erase.
- Installer: choose a local macOS installer or download a compatible installer from Apple; see download status.
- USB drive: choose the drive to use. Drives that are too small are marked.
- Review: check what will be erased, confirm, and authorize the erase with Touch ID when available or your administrator password otherwise.
- Creating: Relente asks its helper to run Apple's signed
createinstallmedia, shows available progress and elapsed time, and verifies the resulting installer volume before marking it ready. The creation screen shows the current phase; copied bytes appear when measured. The command erases the selected drive.
When it's done, the app explains how to start up from the drive on a Mac with Apple silicon or with an Intel processor. Apple's guide Create a bootable installer for macOS covers the same steps from the command line.
- In Relente, choose Uninstall System Helper… from the app menu. (You can also turn it off in System Settings → General → Login Items & Extensions.)
- Move Relente to the Trash.
Relente has two parts:
- The app runs without special privileges. It shows the interface, finds macOS installers, and detects removable drives.
- A small system helper runs as root, registered through
SMAppService. It formats a drive and runs the selected installer's signedcreateinstallmediawith real progress. It has no network access and accepts requests only from the signed Relente app.
Before erasing anything, the helper checks on its own that the drive is external and removable, that it is not the startup disk, and that it's the same physical drive you confirmed. It also validates Apple's signature on the installer and its createinstallmedia tool. See SECURITY.md for details.
This is a personal project and pull requests aren't accepted for now. Bug reports and ideas are welcome as issues. See CONTRIBUTING.md.
Relente is in early development. See release readiness for recorded validation and remaining follow-up.
Relente follows an AI-native software development lifecycle. Change artifacts live in intent/, and project rules are in AGENTS.md.
Relente is released under the MIT License.
Relente is not affiliated with or endorsed by Apple. macOS is a trademark of Apple Inc.