Install the CLI

The public CLI beta supports Apple Silicon macOS only. Its binary is checksummed but not yet signed, notarized, or universal. Source repositories remain private; reviewed binary releases are distributed through the public c6shq/tap boundary.

Prerequisites

• an Apple Silicon Mac;
• Homebrew for the recommended Formula path, or curl and sh for the standalone path.

Install with Homebrew

Use the fully qualified Formula name. Homebrew adds the public tap and trusts only the selected Formula:

brew install c6shq/tap/c6s

The Formula uses an immutable versioned URL and exact SHA-256 checksum.

Install without Homebrew

The standalone installer downloads the latest public binary mirror, verifies it against checksums.txt, checks the one-file archive layout, and atomically installs to ~/.local/bin/c6s:

curl -fsSL https://c6s.whitekiwi.link/install.sh | sh

If ~/.local/bin is not already on PATH, add it using the normal configuration for your shell. The installer does not edit shell startup files. To pin a release or choose another directory:

curl -fsSL https://c6s.whitekiwi.link/install.sh | \
  C6S_VERSION=v0.1.1 C6S_INSTALL_DIR="$HOME/.local/bin" sh

Verify

c6s version
c6s protocol verify

Initialize local device keys

c6s device setup
c6s device status

On macOS, setup stores independent encryption and signing key material in login Keychain using a device-only, when-unlocked accessibility class. The command prints only public fingerprints and a local display identifier.

Update

For Homebrew installs, run brew upgrade c6s. For standalone installs, repeat the one-line installer; it verifies and atomically replaces the executable.