Crypto engines

MPCKit delegates DKG and centralized-signature math to a CryptoEngine. Two implementations ship with the SDK.

InlineCryptoEngine

The default. Runs the math on the calling thread. Fine for Node.js backends and CLI tools where blocking the event loop briefly is OK.

import { MPCKit } from "@mpckit/sdk";

const api = new MPCKit({
  baseUrl: "https://api.mpckit.xyz",
  apiKey,
  network: "testnet",
  // crypto omitted: InlineCryptoEngine is the default
});

WebWorkerCryptoEngine

For browsers. Moves the WASM-heavy math off the main thread so DKG and signing don't block UI work or animations.

import { MPCKit, createWebWorkerCryptoEngine } from "@mpckit/sdk";

const worker = new Worker(
  new URL("@mpckit/sdk/worker-impl", import.meta.url),
  { type: "module" },
);

const api = new MPCKit({
  baseUrl: "https://api.mpckit.xyz",
  apiKey,
  network: "testnet",
  crypto: createWebWorkerCryptoEngine(worker),
});

The exact new Worker(...) shape is bundler-specific. For React applications, the React SDK provider handles this for you when you set useWorker: true.

Bundler shapes

new Worker(
  new URL("@mpckit/sdk/worker-impl", import.meta.url),
  { type: "module" },
);

new Worker(
  new URL("@mpckit/sdk/worker-impl", import.meta.url),
  { type: "module" },
);

new Worker(new URL("@mpckit/sdk/worker-impl", import.meta.url));

Custom engines

CryptoEngine is an interface. Implement it if you want to drive the protocol from your own crypto pipeline (FFI, hardware, alternative WASM build). The interface is exported from the SDK root:

import type { CryptoEngine } from "@mpckit/sdk";

The two methods you implement are prepareDkg and prepareSign. See the type definitions for the exact shape; both take the protocol public parameters plus the seed-derived state and return the bytes the backend expects.