Rust Integration
Seamless integration with rules_rust for building WebAssembly components with wit-bindgen.
WebAssembly Component Rules
Build production-ready WebAssembly components with Bazel
What is the WebAssembly Component Model?
Section titled “What is the WebAssembly Component Model?”The WebAssembly Component Model is a revolutionary approach to building portable, secure, and composable software. Think of it as “microservices for WebAssembly” - you can build small, focused components in any language and connect them together like LEGO blocks.
Why Should You Care?
Section titled “Why Should You Care?”Language Freedom: Write your auth service in Rust, your API in Go, your frontend in JavaScript, and your ML pipeline in Python - all running together seamlessly.
Performance: Near-native speed with WebAssembly’s efficiency, but with the safety and portability of sandboxed execution.
📦 True Portability: Build once, run anywhere - from edge devices to cloud servers, from browsers to embedded systems.
🔒 Security by Default: Each component runs in its own sandbox with explicit interfaces - no hidden dependencies or side effects.
Real-World Use Cases
Section titled “Real-World Use Cases”- Microservices: Replace Docker containers with lightweight WASM components
- Plugin Systems: Add extensibility to your apps with secure, fast plugins
- Edge Computing: Deploy the same code to CDN edges, IoT devices, and cloud
- Multi-language Projects: Combine the best tools from different ecosystems
Why rules_wasm_component?
Section titled “Why rules_wasm_component?”Building WebAssembly components traditionally involves complex toolchains and manual configuration. rules_wasm_component makes it as easy as:
rust_wasm_component_bindgen( name = "my_service", srcs = ["src/lib.rs"], wit = ":my_interfaces",)That’s it! Bazel handles the complexity while you focus on building great software.
Features
Section titled “Features”Go Support
TinyGo v0.38.0 with WASI Preview 2 component support and official BytecodeAlliance modules.
C++ Components
Native C++ component development with WASI SDK and Preview2 direct compilation.
JavaScript/TypeScript
ComponentizeJS integration for building WebAssembly components from JS/TS source code.
WAC Composition
WebAssembly Composition (WAC) support for building complex multi-component systems.
OCI Publishing
Publish and distribute components via container registries with multi-registry support.
Digital Signing
Component signing with wasmsign2 and verification for secure deployments.
Performance
Wizer pre-initialization for 1.35-6x startup performance improvements.
WRPC Integration
Remote procedure calls between components with wrpc bindings and distributed architecture.
Multi-Architecture
Build and distribute components for multiple WebAssembly targets and platforms.
Enterprise Security
Security policies, component signing verification, and enterprise-grade deployment controls.
Advanced Composition
Microservices patterns, distributed systems, and hybrid local/remote component orchestration.
Quick Example
Section titled “Quick Example”Create your first WebAssembly component in just a few steps:
load("@rules_wasm_component//wit:defs.bzl", "wit_library")load("@rules_wasm_component//rust:defs.bzl", "rust_wasm_component_bindgen")
wit_library( name = "hello_interfaces", srcs = ["hello.wit"], package_name = "hello:world@1.0.0",)
rust_wasm_component_bindgen( name = "hello_component", srcs = ["src/lib.rs"], wit = ":hello_interfaces",)Supported Languages
Section titled “Supported Languages”Build WebAssembly components in your preferred language:
Rust
Full Component Model support with wit-bindgen integration and multiple build profiles.
Learn more →