Watchtower

The Watchtower is an auto-challenger framework for optimistic rollups. It follows a rollup's settlement batches, surfaces each new batch and its challenge-window deadline, and — when your validity predicate rejects a batch — hands it to your onInvalid callback so you can wire up a challenge.

The framework watches and decides when; you supply the validity check. The Watchtower never decides on its own that a batch is fraudulent — it calls your validate function and acts on what you return.

watchBatches

import { createRdkClient, watchBatches, challengeBatch } from "@qorechain/rdk";

// The public qore.host REST + RPC endpoints are baked into the presets
// (RDK ≥ 0.4.2); the RPC endpoint is what broadcasts a challenge. Pass
// `endpoints` only to target your own node.
const rdk = createRdkClient({ network: "testnet" });

const watcher = watchBatches(rdk, "my-roll", {
  onBatch: (batch) => {
    console.log("new batch", batch.index);
  },

  // Your validity predicate. Return false to flag the batch as invalid.
  validate: async (batch) => {
    return await isBatchValid(batch); // your logic
  },

  // Called when validate() returns false — wire it to a challenge.
  onInvalid: async (batch) => {
    await challengeBatch(rdk, "my-roll", batch.index /* + your fraud proof */);
  },

  // Called as a batch approaches the end of its challenge window.
  onDeadline: (batch) => {
    console.warn("challenge window closing for batch", batch.index);
  },
});

// Later:
watcher.stop();

The framework surfaces:

• new batches via onBatch,
• challenge-window deadlines via onDeadline, and
• invalid batches (where your validate returned false) via onInvalid.

Wiring onInvalid to challengeBatch turns the Watchtower into a complete auto-challenger; leave it unset to run in observe-only mode.

CLI

qorollup watchtower my-roll

watchtower runs the framework from the command line, printing new batches and challenge-window deadlines until you press Ctrl-C. See Deploying a Rollup for the full qorollup operator CLI.