Prover worker and CLI

The SDK builds each proof in a Web Worker, from WebAssembly it ships. Your app serves those files one of two ways:

Copy the shipped filesCopy Anchor Link

The package installs a command, nimbus-solana-web, with one subcommand:

nimbus-solana-web copy-assets <directory>

It copies the browser files the SDK runs into <directory>, which your app serves as static files. It takes exactly one argument and no options. Run it from a package script, as the example app does:

{
  "scripts": {
    "assets": "nimbus-solana-web copy-assets public/nimbus"
  }
}

Then pass the URL that directory is served at to loadNimbusSdk:

import { loadNimbusSdk } from "@umbra/nimbus-solana-web";

const sdk = await loadNimbusSdk(
  { cluster: "mainnet" },
  { assetsBaseUrl: "/nimbus/" },
);

What it copiesCopy Anchor Link

• nimbus_primitives_wasm_bg.wasm, the WebAssembly loadNimbusSdk loads.
• prover-worker.js, the worker each proof runs in.
• prover/ and witness-graph/, the WebAssembly the worker proves with.

It creates the directory when it does not exist. It overwrites files of the same names and touches no other file. Run it again each time you update the package, so the files match the version you installed.

copy-assets lists its exit codes.

Start your own workerCopy Anchor Link

Skip this section unless your build must bundle the prover's WebAssembly itself.

Your worker module answers each message with proveWorkerRequest, from the package's ./prover-worker entry. Its whole body is:

import initGraph, * as graph from "./umbra_witness_graph.js";
import initProver, * as wasm from "./umbra_prover.js";
import { proveWorkerRequest } from "@umbra/nimbus-solana-web/prover-worker";

self.addEventListener("message", (event) => {
  void Promise.all([initGraph(), initProver()])
    .then(async () => proveWorkerRequest(event.data, { graph, wasm }))
    .then((answer) => self.postMessage(answer));
});

This block is not type-checked here. It imports two files that your own build writes: the witness-graph and prover glue code.

Then pass a function that starts your worker as platform.startProverWorker:

import { loadNimbusSdk } from "@umbra/nimbus-solana-web";

const sdk = await loadNimbusSdk(
  { cluster: "mainnet" },
  {
    endpoints: { primitivesWasm: "/wasm/nimbus_primitives_wasm_bg.wasm" },
    platform: {
      startProverWorker: () => new Worker(proverWorkerUrl, { type: "module" }),
    },
  },
);

Without assetsBaseUrl, pass endpoints.primitivesWasm too. It is the URL your app serves the SDK's main WebAssembly file at.

The SDK starts a fresh worker for each proof and terminates it afterwards. Each request carries the user's private inputs, so a worker is never reused.

NextCopy Anchor Link