Radian

Radian is a fast coding agent in a single Rust binary with a headless JSON mode and full-screen app.

Radian is a fast and efficient coding agent packaged as a single Rust binary with no runtime to boot. It is built to fit into pipelines and be orchestrated by other agents, taking prompts through a headless command that prints each step as a JSON line and exits with a specific status code. Every step goes to a journal that can be resumed and forked, and parallel work runs inside one reply with multiple subagent calls. It reads instruction files, shares skills and MCP servers, supports hooks, and imports theme files. Built-in arc turns requests into tasks, runs them as headless workers, and merges passing results. It runs on macOS and Linux via Homebrew, release tarballs, or Cargo.

Radian at a glance

Best for: Software engineer
Runs on: macOS, Linux, CLI
Pricing: Open source under MIT or Apache-2.0
Released: October 2026
Category: AI coding tool
Website: getrad.dev

Key features

Native binary with no runtime
Headless command with JSON output
Journaling for resume and fork
Budget guard for context windows
Built-in arc task runner and merger
Support for instruction files and skills
MCP server integration
Sandbox isolation switch

Use it for

Run automated coding tasks in CI pipelines
Orchestrate coding agents via CLI
Manage parallel subagent calls
Execute tasks using instruction files and MCP servers

Alternatives to Radian

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jevgrep — Reduces coding agent costs by providing targeted, relevant repository context.
Rune — A native, high-performance editor with integrated Unix-based tool workflows.
Dirac — Executes complex coding tasks efficiently with hash-anchored edits and low token overhead.
Zed — Very fast native editor with parallel agents and multiplayer
zerostack — Minimal memory footprint and high CPU efficiency compared to JS-based agents.
pmtui — Manages long-running agent sessions with an automated heartbeat and dashboard.
Zero — Operates entirely on the local machine with configurable permission-gated actions.
jcode — Optimized for massive parallelism with low memory usage per session.
Tunr — Deploys agent-built software and shares local dev servers instantly via a single command.
Unspin — Shows live progress, step names, and ETAs for coding agent shell commands instead of a spinner.
rhun — It is a small, fast editor written in assembly.

All Radian alternatives