# How to Automate Tasks in the Brush Project: Complete Script Guide > Automate tasks in the Brush project with npm scripts and Python utilities. Streamline building, development servers, and benchmarks. Learn more. - Repository: [Arthur Brussee/brush](https://github.com/ArthurBrussee/brush) - Tags: how-to-guide - Published: 2026-05-14 --- **The Brush repository provides npm scripts and Python utilities that automate building WebAssembly modules, running development servers, and generating benchmark data without manually invoking underlying toolchains.** The Brush project, hosted at `ArthurBrussee/brush`, streamlines Gaussian splatting workflows through a unified set of automation scripts defined across workspace [`package.json`](https://github.com/ArthurBrussee/brush/blob/main/package.json) files. These scripts handle the complex orchestration between Rust, WebAssembly, and Node.js toolchains, while a Python helper supports benchmark automation. Whether you are developing the core library or deploying the web interface, these automation hooks in the root [`package.json`](https://github.com/ArthurBrussee/brush/blob/main/package.json) and application directories serve as the canonical entry points for all routine tasks. ## Development Server Automation The repository provides distinct development environments for the main application and the JavaScript library bindings. These scripts abstract the Vite configuration and Wasm initialization into single commands. ### Starting the Web Interface To launch the **brush-app** web interface with hot-reloading, run `npm run dev` from the repository root. This command delegates to [`apps/brush-app/web/package.json`](https://github.com/ArthurBrussee/brush/blob/main/apps/brush-app/web/package.json), starting a Vite development server typically accessible at `http://localhost:5173`. The root [`package.json`](https://github.com/ArthurBrussee/brush/blob/main/package.json) also exposes `npm run dev:app` as an explicit shortcut to this same endpoint. ```bash # Start the brush-app development server npm run dev ``` ### Building the JavaScript Library For developers working on the `brush-js` JavaScript bindings specifically, the root [`package.json`](https://github.com/ArthurBrussee/brush/blob/main/package.json) defines `npm run dev:lib`. This command targets [`apps/brush-js/web/package.json`](https://github.com/ArthurBrussee/brush/blob/main/apps/brush-js/web/package.json) to initialize the library development environment separately from the main application frontend. ```bash # Start development mode for the brush-js library npm run dev:lib ``` ## Production Build Automation Production builds require compiling Rust code to WebAssembly before bundling with Vite. The automation scripts handle both development and release optimizations through distinct build paths. ### WebAssembly Compilation Modes The [`apps/brush-app/web/package.json`](https://github.com/ArthurBrussee/brush/blob/main/apps/brush-app/web/package.json) defines granular Wasm build commands using **wasm-pack**. Use `npm run build:wasm-dev` to compile with `--dev` flags for faster iteration during development, or `npm run build:wasm-release` to compile with `--release` flags for optimized runtime performance. ```bash # Development build (faster compilation, slower runtime) npm run build:wasm-dev # Production build (slower compilation, optimized output) npm run build:wasm-release ``` ### Full Production Bundling The `npm run build:app` command chains the Wasm compilation with `vite build` to produce the complete static site. The root-level `npm run build` provides a convenience wrapper that invokes `build:app` and manages workspace dependencies. After building, use `npm run preview` to serve the `./dist/` folder locally using `vite preview` for final verification. ```bash # Build the complete production bundle (Wasm + Vite) npm run build # Preview the production build locally npm run preview ``` ## Benchmark Data Generation The benchmark suite relies on reference data generated via [`crates/brush-bench-test/test_cases/generate_reference.py`](https://github.com/ArthurBrussee/brush/blob/main/crates/brush-bench-test/test_cases/generate_reference.py). This Python script processes synthetic scenes, executes forward passes through the rendering pipeline, and persists outputs as `.safetensors` files for regression testing. ```bash # Generate reference data for benchmark tests python crates/brush-bench-test/test_cases/generate_reference.py ``` ## Continuous Integration The GitHub Actions workflow in [`.github/workflows/ci.yml`](https://github.com/ArthurBrussee/brush/blob/main/.github/workflows/ci.yml) validates these automation scripts by executing `npm ci`, `npm run build`, and Cargo tests. This ensures every commit maintains build integrity across the Rust and JavaScript boundaries, confirming that the npm scripts remain the authoritative method for **automating tasks in the Brush project**. ```bash # The CI workflow runs these same commands automatically npm ci npm run build cargo test ``` ## Summary - Use `npm run dev` in the root directory to start hot-reloading development servers for web applications via [`apps/brush-app/web/package.json`](https://github.com/ArthurBrussee/brush/blob/main/apps/brush-app/web/package.json). - Compile WebAssembly in development mode with `npm run build:wasm-dev` or release mode with `npm run build:wasm-release` as defined in the app-specific package files. - Generate production bundles using `npm run build`, which orchestrates both Wasm compilation and Vite bundling into the `./dist/` folder. - Create benchmark reference data by executing `python crates/brush-bench-test/test_cases/generate_reference.py`. - Trust the CI pipeline in [`.github/workflows/ci.yml`](https://github.com/ArthurBrussee/brush/blob/main/.github/workflows/ci.yml) to validate all automation paths on every commit using the same npm scripts. ## Frequently Asked Questions ### What is the difference between `npm run dev` and `npm run dev:lib`? `npm run dev` starts the **brush-app** UI development server defined in [`apps/brush-app/web/package.json`](https://github.com/ArthurBrussee/brush/blob/main/apps/brush-app/web/package.json), while `npm run dev:lib` launches the development environment for the **brush-js** JavaScript bindings library in [`apps/brush-js/web/package.json`](https://github.com/ArthurBrussee/brush/blob/main/apps/brush-js/web/package.json). Use the former when working on the user interface and the latter when modifying the core JavaScript API. ### How do I build just the WebAssembly module without bundling the entire web UI? Execute `npm run build:wasm-release` or `npm run build:wasm-dev` from within the `apps/brush-app/web` directory. These scripts invoke `wasm-pack build` directly with the appropriate `--release` or `--dev` flags, producing the `./pkg/` output without triggering the Vite bundling step that `npm run build` would initiate. ### Can I run the benchmark reference generator without installing Python dependencies manually? The script at [`crates/brush-bench-test/test_cases/generate_reference.py`](https://github.com/ArthurBrussee/brush/blob/main/crates/brush-bench-test/test_cases/generate_reference.py) requires Python and dependencies compatible with the Rust benchmark crate's expectations. Ensure your Python environment matches the project specifications, then invoke the script directly to generate the `.safetensors` reference files used by the test suite. ### Which script should I use for production deployment? Use `npm run build` from the repository root, which triggers the full release pipeline defined across the workspace [`package.json`](https://github.com/ArthurBrussee/brush/blob/main/package.json) files, including optimized WebAssembly compilation via `wasm-pack` and Vite bundling. Verify the output locally using `npm run preview` before deploying the `./dist/` contents.