Rust

Cloudflare supports Rust Workers through the workers-rs crate. worker-build compiles Rust to WebAssembly and emits an ES module shim; project-local Wrangler uploads both as a standard module Worker. This output shape is supported by open-compute.

Create the project

Install the wasm32-unknown-unknown target and generate the official template:

rustup target add wasm32-unknown-unknown
cargo install cargo-generate
cargo generate cloudflare/workers-rs

Keep Wrangler installed in the generated project. The open-compute launcher deliberately resolves the nearest project-local Wrangler rather than a global executable.

Write the Worker

Use the event macro in src/lib.rs to expose the fetch handler:

use worker::*;

#[event(fetch)]
async fn main(_request: Request, _env: Env, _ctx: Context) -> Result<Response> {
    Response::ok("Hello from Rust!")
}

The Wrangler configuration points at the generated shim and runs worker-build before upload:

{
  "$schema": "./node_modules/wrangler/config-schema.json",
  "name": "hello-rust",
  "main": "build/worker/shim.mjs",
  "compatibility_date": "2026-09-08",
  "build": {
    "command": "worker-build --release"
  }
}

All dependencies must compile for wasm32-unknown-unknown. Install worker-build explicitly or keep the build command produced by the official template.

Develop and deploy

Use Wrangler for the local loop, then use open-compute to select and authenticate the real target:

npx wrangler dev
ocd wrangler deploy

ocd wrangler deploy runs the same custom build command, then uploads the generated JavaScript shim and .wasm module. No Rust toolchain is needed on the production host after the immutable deployment has been created.

Cloudflare reference: Rust language support.