Claude Code Rust

A native Rust terminal interface for Claude Code. Drop-in replacement for Anthropic's stock Node.js/React Ink TUI, built for performance and a better user experience.

About

Claude Code Rust replaces the stock Claude Code terminal interface with a native Rust binary built on Ratatui. It connects to the same Claude API through a local Agent SDK bridge. Core Claude Code functionality - tool calls, file editing, terminal commands, and permissions - works unchanged.

Requisites

• Node.js 18+ (for the Agent SDK bridge)
• Existing Claude Code authentication (~/.claude/config.json)

Install

npm (global, recommended)

npm install -g claude-code-rust

The published package installs a claude-rs command and fetches the matching prebuilt release binary for your platform during install.

If claude-rs resolves to an older global shim, ensure your npm global bin directory comes first on PATH or remove the stale shim before retrying.

Usage

claude-rs

Why

The stock Claude Code TUI runs on Node.js with React Ink. This causes real problems:

• Memory: 200-400MB baseline vs ~20-50MB for a native binary
• Startup: 2-5 seconds vs under 100ms
• Scrollback: Broken virtual scrolling that loses history
• Input latency: Event queue delays on keystroke handling
• Copy/paste: Custom implementation instead of native terminal support

Claude Code Rust fixes all of these by compiling to a single native binary with direct terminal control via Crossterm.

Architecture

Three-layer design:

Presentation (Rust/Ratatui) - Single binary with an async event loop (Tokio) handling keyboard input and bridge client events concurrently. Virtual-scrolled chat history with syntax-highlighted code blocks.

Agent SDK Bridge (stdio JSON envelopes) - Spawns agent-sdk/dist/bridge.js as a child process and communicates via line-delimited JSON envelopes over stdin/stdout. Bidirectional streaming for user messages, tool updates, and permission requests.

Agent Runtime (Anthropic Agent SDK) - The TypeScript bridge drives @anthropic-ai/claude-agent-sdk, which manages authentication, session/query lifecycle, and tool execution.

Status

This project is pre-1.0 and under active development. See CONTRIBUTING.md for how to get involved.

Limitations

Startup is still constrained by the upstream Claude Agent SDK runtime that this TUI wraps. The Rust interface itself is fast, but end-to-end readiness can still take noticeable time before a session is fully available. Improving that remains an active area of work.

License

This project is licensed under the Apache License 2.0. Apache-2.0 was chosen to keep usage and redistribution straightforward for individual users, downstream packagers, and commercial adopters.

Disclaimer and Legal Notice

This project is not affiliated with, endorsed by, or supported by Anthropic.

A quick note on where this project stands, since I know people worry about this kind of thing: claude-code-rust is a terminal UI that I wrote from scratch in Rust. It is not a fork, copy or port of the latest Claude Code source leak -- it talks to Anthropic's official Agent SDK as a runtime dependency instead, the same way any other third-party tool would. No Anthropic source code was read or used as reference at any point during development.

The project uses your existing Claude Code subscription via the Agent SDK and the Agent SDK's terms allow building on top of it. Other community projects do the same. As far as I can tell, using this project is fine -- but I am a single maintainer, not a lawyer. If anything changes on Anthropic's end, I will update this section and adjust the project accordingly.

This project's source code is licensed under Apache-2.0. The Agent SDK itself is proprietary and governed by Anthropic's Commercial Terms of Service.

For official Claude documentation, see https://claude.ai/docs.