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WebAssembly / WASM

Overview​

info

WebAssembly / WASM is currently only live on the Datil-Dev network. Please reach out to us if you'd like to use it on another network.

You can run WebAssembly / WASM within a Lit Action. This is useful if you want to run something other than JavaScript within a Lit Action.

Example

This example loads some WebAssembly code that exposes an add function. It then calls this function with the arguments 123 and 456, and sets the response to the result. How to create a bundle with your WebAssembly code is beyond the scope of this documentation, but there are many guides online. You are free to mix JS and WASM within a single Lit Action, as you can see in the example below.

const wasmCode = new Uint8Array([
  0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x01, 0x07, 0x01, 0x60, 0x02,
  0x7f, 0x7f, 0x01, 0x7f, 0x03, 0x02, 0x01, 0x00, 0x07, 0x07, 0x01, 0x03, 0x61,
  0x64, 0x64, 0x00, 0x00, 0x0a, 0x09, 0x01, 0x07, 0x00, 0x20, 0x00, 0x20, 0x01,
  0x6a, 0x0b,
]);
const wasmModule = new WebAssembly.Module(wasmCode);
const wasmInstance = new WebAssembly.Instance(wasmModule);
const { add } = wasmInstance.exports;
const sum = add(123, 456);
Lit.Actions.setResponse({ response: JSON.stringify({ sum }) });