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CKB Transaction Firewall CKB Transaction Firewall

Step 4: Handle a Stale Registry Cell

The most common production failure is a stale registry cell: the outpoint you cached was consumed by a governance update, and fetchRegistryPayload throws because that cell no longer exists.

We will simulate this by passing a deliberately wrong transaction hash, then write the recovery pattern.

Replace check.ts with:

import { findRegistryCell, fetchRegistryPayload, preflightCheck } from "@ckb-firewall/sdk";


const RPC_URL = "https://testnet.ckb.dev";


const REGISTRY_SPEC = {
  codeHash:    "0x493f1700508125b0e281b8fb1d168b03bd5ef71480399dd59221224901a9cd09",
  hashType:    "type" as const,
  typeIdValue: "0x9be0ad6e4e5039a64d9725ff037057c16ef59f126e3bdd9841b802f0e0a112fe",
  required:    true,
};


// Simulate a stale cached outpoint
let cachedTxHash = "0x0000000000000000000000000000000000000000000000000000000000000000";
let cachedIndex = 0;


async function loadRegistry() {
  try {
    return await fetchRegistryPayload(RPC_URL, cachedTxHash, cachedIndex);
  } catch (err) {
    if (err instanceof Error && err.message.includes("is not live")) {
      console.log("Registry cell is stale — rediscovering via indexer...");
      const fresh = await findRegistryCell(RPC_URL, REGISTRY_SPEC);
      cachedTxHash = fresh.txHash;
      cachedIndex = fresh.index;
      return await fetchRegistryPayload(RPC_URL, cachedTxHash, cachedIndex);
    }
    throw err;
  }
}


const registry = await loadRegistry();
console.log(`Registry loaded: ${registry.entries.length} active entries`);
console.log(`Current outpoint: ${cachedTxHash}:${cachedIndex}`);


const result = preflightCheck([{ lockArgs: "0x331cdd72ff9f7f22c53f9710d6639ca46de3ac06" }], [registry]);
console.log(result.ok ? "✓ Output is clean" : `✗ Blocked: ${result.reason}`);

Run it:

Terminal window
npx tsx check.ts

Expected output:

Registry cell is stale — rediscovering via indexer...
Registry loaded: 2 active entries
Current outpoint: 0xa3dcb46f...:0
✓ Output is clean

The recovery pattern is: catch “is not live”, call findRegistryCell to get the fresh outpoint, update your cache, and retry. Your application can then persist the fresh outpoint for subsequent calls.

Continue to Step 5.