omnictl is the command-line tool for Omni that allows you to authenticate, manage, and interact with Talos-based Kubernetes clusters through its centralized API. Follow the instructions below to install and configure omnictl for your operating system. Install omnictl and the kubectl oidc-login plugin automatically with Homebrew:
brew install siderolabs/tap/sidero-tools
This will install and update talosctl, omnictl, and kube-oidc_login.

Manual installation

Download omnictl from the Omni dashboard. The downloaded binary will be named according to the selected platform and architecture (e.g. omnictl-linux-amd64). Rename this binary to omnictl, make it executable, and move it into your PATH. For example, to do so on a mac:
mv omnictl-darwin-arm64 omnictl
chmod +x omnictl
mv omnictl /usr/local/bin

2. Configuration File

Download omniconfig from the Omni dashboard. Omnictl follows the XDG Base Directory Specification for its configuration files location. Omni configuration is stored under $XDG_CONFIG_HOME/omni/config. This means, the correct configuration file locations for omniconfig are the following:
OSOmniconfig Path
Linux~/.config/omni/config
MacOS~/Library/Application Support/omni/config
Windows%LOCALAPPDATA%\omni\config, e.g., C:\Users<USER>\AppData\Local\omni\config
Add the downloaded omniconfig.yaml to the default location for your OS to use it with omnictl:
cp omniconfig.yaml <LOCATION_FOR_YOUR_OS_ABOVE>
If you would like to merge the omniconfig.yaml with an existing configuration, use the following command:
omnictl config merge ./omniconfig.yaml
List the contexts to verify that the omniconfig was added:
$ omnictl config contexts
CURRENT   NAME         URL
          ...
          example      https://example.omni.siderolabs.io/
          ...
Run omnictl for the first time to perform initial authentication using a web browser:
omnictl get clusters
If the browser window does not open automatically, it can be opened manually by copying and pasting the URL into a web browser:
BROWSER=echo omnictl get clusters