Install

ulo ships as one native binary for macOS and glibc Linux, on ARM64 and x86-64.

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Install

Shell

The installer picks the release for your platform, verifies its checksum, and writes the binary to ~/.local/bin. Set ULO_INSTALL_DIR to choose another directory. If your shell's PATH does not include that directory, add it. Then check the build with ulo --version.

Package managers

Package managers install the same binary:

Shell

brew install arocomputer/tap/ulo
npm install -g @arocomputer/ulo
bun add -g @arocomputer/ulo

These packages carry the native binary and need no JavaScript runtime. They arrive with the first package-enabled release.

Migrate an existing installation

The product was previously named e. Install ulo with the commands above, then update command invocations and E_* environment variables to ULO_*. The explicit configuration override is now ULO_HOME.

ulo prefers ~/.ulo. If it is absent, an existing ~/.e remains the active store, including settings, credentials, sessions, and installed packages. Local and PR builds apply the same rule to their -dev and -pr directories. Trusted workspace resources prefer .ulo and fall back to .e.

To move the store, stop running sessions first and run this only when the destination does not exist:

Shell

The directories are never merged automatically. If both exist, select the one you want with ULO_HOME. Update extension scripts that refer to the old path or environment variables. Existing session and configuration formats remain readable.

Update

Update with the method that installed ulo:

Shell

ulo update                            # curl or a release archive
npm install -g @arocomputer/ulo@latest
bun add -g @arocomputer/ulo@latest
brew upgrade arocomputer/tap/ulo

A curl installation checks for updates at launch and installs one in the background. To turn that off, set auto_update in settings.

ulo leaves a package-managed installation to its package manager. In that case, ulo update tells you so instead of replacing the binary.

Try a PR preview

A pull request can be built on request without publishing anything, so you can try an unreviewed change before it merges:

Shell

The build is pinned to the PR's commit and installs as ulo-pr-123 with its own home, ~/.ulo-pr/<commit>, kept apart from production. PR code is unreviewed; use a disposable project. Releases and testing covers the preview workflow and the local ./x dev build.

To install a specific production version with the shell installer, pass --version X.Y.Z. npm and bun accept the exact version after @.

Requirements

The Linux binaries link against glibc 2.39 or newer. That means Ubuntu 24.04+, Debian 13+, Fedora 40+, or RHEL 10+.

On an older distribution, build from source or use the published image. The image carries its own runtime:

Shell

Build from source

Building from source needs Rust 1.98 or newer:

Shell

From a checkout, run ./x dev /path/to/project to run the code you are editing without installing it.