Once JavaScript Software Development Kit

buildonce exposes Once primitives to Node.js. It loads the same native Once library used by the other language libraries and does not expose script execution.

const { Cache } = require("buildonce");

async function example() {
  const cache = new Cache();
  const digest = await cache.putBlob(Buffer.from("hello"));
  const bytes = await cache.getBlob(digest);

  console.assert(bytes.equals(Buffer.from("hello")));
}

The package looks for a bundled native library under prebuilds/. Set ONCE_LIBRARY_PATH to load a custom libonce build.

Use new Cache({ workspaceRoot }) to share the effective provider configured for a repository, or new Cache({ localCacheRoot }) for isolation. Use putFile and getBlobToFile for large payloads so the host does not need to hold their complete contents in JavaScript memory. ActionKey builds a stable digest from ordered, labeled inputs.