radian

radian is a coding agent built around a single Rust binary. Rather than shipping a runtime or a heavyweight service, it starts directly and keeps context spending limited to the lines a task actually needs. The project is open source under MIT or Apache-2.0 and can be installed via Homebrew through the hisea tap, with documentation and source available on GitHub.

The core feature is headless operation. When invoked non-interactively, radian prints every step as a JSON line and exits with a code that indicates how the run ended, so scripts and CI jobs can consume its output without parsing prose. In interactive use it shows its reasoning, runs shell commands such as tests, and reports exit status, as illustrated by a session finishing an ADR slice and showing the diff.

Because the agent is designed to fit into a pipeline, it is aimed at developers and platform engineers who want automated coding or task execution inside existing build and review workflows. Teams already using command-line tooling and JSON-based log processing will find the output format familiar and easy to integrate.

A practical approach is to start with the Homebrew install, try the headless command on a small, well-scoped task, and inspect the JSON lines and exit codes before wiring it into CI. Keep tasks narrow so context stays focused, and rely on the exit code for pass/fail gating rather than parsing free-form text.

In short, radian trades graphical polish for pipeline friendliness, making it a reaso