# Installing

otisk is one binary, `otisk`, which talks to a gateway over SSH. Installing it
needs no credential: the packages and their signatures are public, and your
SSH key is what identifies you once you use it.

## Arch

Trust the key that signs otisk's releases, once. Check the fingerprint rather
than believing the file:

```sh
sudo pacman-key --add release-key.gpg
sudo pacman-key --finger 79F62868A12BC6B9   # 2FDF 670A A060 F841 8BC9  33EB 79F6 2868 A12B C6B9
sudo pacman-key --lsign-key 79F62868A12BC6B9
```

Add the repository to the end of `/etc/pacman.conf`:

```ini
[otisk]
SigLevel = Required DatabaseRequired
Server = https://pub-0e2e5578296e460fa8f9f693f4ad4411.r2.dev/arch/$arch
```

`Required DatabaseRequired` means pacman installs nothing from this repository
that key has not signed, and reads no database it has not signed either.

```sh
sudo pacman -Sy
sudo pacman -S otisk
otisk version
```

## macOS

Homebrew checks the SHA-256 the formula pins, which came from the release
manifest.

```sh
brew tap otiskdev/otisk
brew install otisk
otisk version
```

## From a clone

Go 1.27 or later:

```sh
git clone <the repository> otisk && cd otisk
make build          # bin/otisk and bin/git-gateway
```

`bin/otisk` is the client. `bin/git-gateway` is the server, which you only
need if you are [running one](self-hosting.md).

## Upgrading

Whatever installed it maintains it. The client has no way to update itself.

```sh
sudo pacman -Syu        # Arch, with everything else
sudo pacman -Sy otisk   # Arch, otisk alone
brew upgrade otisk      # macOS
```

Upgrading otisk alone is safe here, though Arch warns against partial upgrades
in general: the client is a static binary linked against nothing, and its
dependencies — `git` and `openssh` — are executables it runs rather than
libraries it links, so there is no version skew for a partial upgrade to
cause.

## What you need besides otisk

`git` 2.29 or later, `ssh`, and `ssh-keygen`. Git 2.29 is the version that
introduced the `proc-receive` hook, which is what makes pushing for review
work.