Rho

Rho is a lightweight agent harness inspired by Pi, built in Rust.

Why Rho

Lightweight: Compare the CLI process overhead and memory usage with other coding harnesses:
Bring your own provider: OpenAI, Kimi, xAI, Anthropic, Gemini, Copilot, Ollama, Ollama Cloud, OpenRouter, and more. Use API keys or subscription plans.
Embeddable SDK: Build headless Rust agents with explicit providers, tools, sessions, and cancellation.

Rho is small on purpose. The pieces power users usually wire up later are already in the binary.

Built-in RTK: when the rtk binary is on your PATH, Rho rewrites shell commands for you. No rtk init, no host hooks. Docs: RTK.
Built-in Herdr: under Herdr, Rho reports agent state, supports pane attach, and handles host image paste. No extra integration. Docs: Herdr.
Coding tools included: read, edit, search, shell, web, skills, and workflows ship with Rho. Install, sign in, work.

Install on macOS and Linux:

curl -fsSL https://matthewyjiang.github.io/rho/install.sh | sh

On Windows PowerShell:

irm https://matthewyjiang.github.io/rho/install.ps1 | iex

Or with Scoop:

scoop bucket add rho https://github.com/matthewyjiang/rho
scoop install rho

Or install from crates.io with Cargo:

cargo install rho-coding-agent

rho

For one-off prompts:

rho run "summarize this repository"

For a deterministic multi-step graph, see the workflow guide.

cargo build
cargo test