cue-rs

Rust bindings for the CUE language runtime, built as a wrapper around libcue — the official C interface to the CUE Go runtime.

[!WARNING] The API is unstable and could change in the future.

libcue exposes the CUE evaluation engine (written in Go) as a C API via cgo. The build script compiles it into a static archive (libcue.a) which is then statically linked into the Rust crate, exposing a safe Rust API on top.

flowchart TD
    subgraph libcue ["libcue (libcue.a)"]
        Go["🐹 Go (CUE runtime)"]
        C["⚙️ C interface (cgo)"]
        Go --> C
    end

    libcue -->|"statically linked"| Rust["🦀 Rust"]

Requirements

• Go 1.24+ — the Go toolchain is required.

Usage

use cue_rs::{Ctx, Value};

let ctx = Ctx::new().unwrap();
let v = Value::compile_string(&ctx, r#"{ name: "alice", age: 30 }"#).unwrap();

v.is_valid().unwrap();
println!("{}", serde_json::from_slice::<serde_json::Value>(&v.to_json_bytes().unwrap()).unwrap());

Examples

More examples can be found in the examples/ directory.