https://github.com/bytecodealliance/jco
JavaScript toolchain for working with WebAssembly Components
https://github.com/bytecodealliance/jco
Last synced: 7 months ago
JSON representation
JavaScript toolchain for working with WebAssembly Components
- Host: GitHub
- URL: https://github.com/bytecodealliance/jco
- Owner: bytecodealliance
- License: apache-2.0
- Created: 2022-12-09T20:51:46.000Z (about 3 years ago)
- Default Branch: main
- Last Pushed: 2025-07-08T02:19:32.000Z (7 months ago)
- Last Synced: 2025-07-08T04:27:53.946Z (7 months ago)
- Language: JavaScript
- Homepage: https://bytecodealliance.github.io/jco/
- Size: 293 MB
- Stars: 782
- Watchers: 19
- Forks: 81
- Open Issues: 67
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Codeowners: CODEOWNERS
Awesome Lists containing this project
- awesome-wasm-components - `jco`
README
jco
JavaScript tooling for WebAssembly Components
A Bytecode Alliance project
Contributing
|
Chat on Zulip
## Overview
Jco (`jco`) provides a [Javascript][js]-native toolchain for working with [WebAssembly Components][cm-book].
**Jco aims to be a convenient multi-tool for the JS WebAssembly ecosystem.**
With Jco (and related projects in this repository), you can:
- **Build WebAssembly components** from Javascript/Typescript with the help of [`componentize-js`][cjs]
- **"Transpile" WebAssembly components** into ES modules that can run in environments like NodeJS and the browser, combining platform-native WebAssembly core support with the advanced features of WebAssembly Components
- **Run WebAssembly components** whether single-shot applications or web servers (similar to [`wasmtime run`][wasmtime-run]/[`wasmtime serve`][wasmtime-serve])
- **Reuse WebAssembly component workflows** (e.g. building components, tranpsiling, etc) from your own JS projects
- **Utilize [`wasm-tools`][wt]** as a library from JS
[cm-book]: https://component-model.bytecodealliance.org/
[js]: https://developer.mozilla.org/en-US/docs/Web/JavaScript
[cjs]: https://github.com/bytecodealliance/componentize-js
[wt]: https://github.com/bytecodealliance/wasm-tools
[wasmtime-serve]: https://docs.wasmtime.dev/cli-options.html#serve
[wasmtime-run]: https://docs.wasmtime.dev/cli-options.html#run
## Organization
As Jco aims to do many things, it contains many subprojects that are organized in this repository:
| Subproject | Language | Directory | Description |
|----------------------------------|------------|-----------------------------------------|-------------------------------------------------------------------------------------------------|
| `jco` | Javascript | `packages/jco` | The `jco` CLI |
| `jco-transpile` | Javascript | `packages/jco-transpile` | WebAssembly Component Transpilation functionaltiy |
| `preview2-shim` | Javascript | `packages/preview2-shim` | Library that provides a mapping of [WASI Preview 2][wasi-p2] for NodeJS and Browsers |
| `preview3-shim` | Javascript | `packages/preview3-shim` | Library that provides a mapping of WASI Preview 3 for NodeJS |
| `js-component-bindgen` | Rust | `crates/js-component-bindgen` | Enables `jco transpile` and other features, reusing the Rust WebAssembly ecosystem |
| `js-component-bindgen-component` | Rust | `crates/js-component-bindgen-component` | WebAssembly component that (when transipled) makes `js-component-bindgen` available in JS `jco` |
| `wasm-tools-component` | Rust | `crates/wasm-tools-component` | WebAssembly component containing pieces of [`wasm-tools`][wt] used by `jco` |
[wasi-p2]: https://github.com/WebAssembly/WASI/tree/main/wasip2
## Quickstart
Jco can be used as either a library import or as a CLI via the `jco` command.
To install it, use `npm` (or your favorite `npm` equivalent):
```console
npm install @bytecodealliance/jco
```
> [!NOTE]
> If you're using jco to build components, you should also install `componentize-js`, which is dynamically imported:
>
> ```console
> npm install @bytecodealliance/componentize-js
> ```
### Building an example component
For instructions on how to build an example component, see the [Component model section on Javascript][cm-book-js].
To see examples of common patterns, check out the [example components folder (`examples/components`)](./examples/components).
[cm-book-js]: https://component-model.bytecodealliance.org/language-support/javascript.html
## Learn more
For a deeper guide on the intricacies of Jco, read the [Jco Book][jco-book].
[jco-book]: https://bytecodealliance.github.io/jco/
## License
This project is licensed under the Apache 2.0 license with the LLVM exception.
See [LICENSE](LICENSE) for more details.
## Contributing
See the [Contributing](https://bytecodealliance.github.io/jco/contributing.html) chapter of the Jco book.
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in this project by you, as defined in the Apache-2.0 license,
shall be licensed as above, without any additional terms or conditions.