fx :Tiny, open, native coding agent.
fx: A Minimalist, Open-Source, Native Coding Agent
fx is a lightweight, native harness and CLI designed for coding agents. Engineered in the Zig language, it is specifically optimized for research purposes and seamless integration into larger software ecosystems.
🚀 Quick Start
To get the agent running on your system, execute the following command:
curl -fsSL https://fx.sh/setup.sh | bash
[!WARNING] Status: Experimental Version
v0.0.4is subject to frequent changes. Pleasetrust it blindlyuse it at your own risk.
🛠 Technical Specifications
The project prioritizes a "less is more" approach, focusing on extreme performance and a tiny footprint.
| Metric | Detail |
|---|---|
| Binary Size | 6.39 MiB |
| Language | Zig |
| License | Apache-2.0 |
| Cold Start | |
| Memory | Single-digit MB baseline |
Architecture & Deployment
The demo version leverages WebAssembly (Wasm) compiled via the Zig toolchain.
- Networking: Handled via browser
fetch. - Workspace: Powered by
just-bash. - Compatibility: Requires browsers with WebAssembly JSPI support (e.g., Chrome or Safari 27+).
🌟 Key Features
- Instantaneous Response: With a cold start of ,
fxeliminates unnecessary I/O before accepting input, making it perfect for programmatic triggers. - Resource Efficiency: Its minimal memory usage allows developers to run numerous concurrent instances on a single machine.
- Wasm Optimization: The
fx.wasmbuild reduces size further and allows for a pluggable network stack. - Unix-Centric UX: Rather than a
bloated TUI IDE,fxfeels like a standard Unix shell, preserving scroll history and maintaining minimal output. - Token Optimization: By using a streamlined system prompt and efficient tools, it reduces costs and improves the Time-to-First-Token (TTFT).
🔌 Extensibility & Agnosticism
fx follows a Unix-like philosophy regarding growth: a small, stable core that is expanded through external modules.
- Extension Points: It can be augmented via skills, plugins, and Model Context Protocols (MCPs).
- Model Flexibility: It is entirely provider-agnostic. You can connect it to:
- Local models
- API Gateways
- Direct provider subscriptions/APIs
For more details on configuration, refer to the SDK documentation or run the following command within the agent:
/help