MLX

Rust bindings for Apple's MLX framework.

Platform: Apple Silicon (macOS) only.

Architecture

The bindings are layered, the same way as MLX Swift:

mlxcore      (safe, idiomatic Rust API)   <- crates/mlxcore
mlxcore-sys  (raw unsafe FFI bindings)    <- crates/mlxcore-sys, generated by bindgen
mlx-c     (Apple's C API for MLX)      <- third_party/mlx-c (git submodule)
mlx       (Apple's C++ framework)      <- fetched by mlx-c's CMake build

MLX itself is C++, which Rust cannot bind to directly. We bind against mlx-c, Apple's official C API, whose CMake build pulls in MLX via FetchContent.

Building

git submodule update --init --recursive
make build
make test

Requirements: a recent Rust toolchain, make, cmake, and Xcode command-line tools. The first build compiles MLX from source and takes several minutes.

Examples

Runnable examples live in crates/mlxcore/examples:

cargo run --example hello

Note: suffix float literals with f32

Unsuffixed float literals are f64 in Rust, and Apple GPUs have no float64 support. Since the default stream is the GPU, &[1.0, 2.0] builds an array that fails on every operation. Write &[1.0f32, 2.0], and &a * 2.0f32 for scalars.

float64 still works on an explicit Stream::cpu().

Features

• metal (default) — GPU backend via Metal.
• accelerate (default) — CPU BLAS via Apple's Accelerate framework.