Native UI and Rust tooling for Elixir.

Elixir Crab builds tools for native software that keeps application behavior, state, supervision, and public contracts in Elixir while using Rust for bounded platform mechanics and performance-sensitive work.

Project	What it does	Hex
gpui	Declarative native desktop UI for Elixir/OTP, with GPUI windows, HEEx-style views, native controls, testing, and remote displays
rustq	Typed Rust and Rustler code generation from Elixir, including quasiquoting, ASTs, and generated NIF boundaries

Elixir application
├── gpui                    — declarative applications, sessions, snapshots, and UI
│   ├── gpui_components     — conventional controls backed by gpui-component
│   └── gpui_native         — statically composed vanilla and component native hosts
└── rustq                   — generated Rust, Rustler boundaries, codecs, and native glue

GPUI keeps authoritative application state, window topology, UI composition, events, and accessibility policy in Elixir. Rust owns the native event loop, rendering, focus, text shaping, IME, measurement, and platform windows. The same application can use native, deterministic test, or remote displays.

The project is distributed as three coordinated packages:

• gpui provides renderer-independent application, UI, text, resource, remote, and testing contracts.
• gpui_components provides conventional declarative controls rendered by gpui-component.
• gpui_native provides complete RustlerPrecompiled vanilla and component hosts while retaining source-build fallback.

RustQ turns typed, Elixir-shaped code into readable Rust. It can derive Rust signatures, codecs, Rustler entrypoints, Elixir stubs, Cargo projects, and complete NIF boundaries from ordinary Elixir modules and typespecs.

RustQ scales from zero-handwritten-Rust NIFs to schema-driven native libraries that retain substantial handwritten Rust for domain and platform mechanics.

Native Elixir software should be able to retain OTP ownership without maintaining repetitive boundary code or moving application policy into Rust. Elixir Crab projects make the boundary typed, inspectable, generated where appropriate, and narrow enough that each runtime does the work it is best at.