Chain upgrade

Performs a chain upgrade using the sudo module. This may brick your chain, so use it as an educational sample. (use substrate purge-chain --dev to remove DB and recover).

// Import the API & Provider and some utility functions
const { ApiPromise, WsProvider } = require('@polkadot/api');
const { typesBundleForPolkadot } = require('@crustio/type-definitions');
// import the test keyring (already has dev keys for Alice, Bob, Charlie, Eve & Ferdie)
const testKeyring = require('@polkadot/keyring/testing');
const fs = require('fs');
async function main () {
// Initialise the provider to connect to the local node
const provider = new WsProvider('ws://');
// Create the API and wait until ready (optional provider passed through)
const api = await ApiPromise.create({
typesBundle: typesBundleForPolkadot
// Retrieve the upgrade key from the chain state
const adminId = await api.query.sudo.key();
// Find the actual keypair in the keyring (if this is a changed value, the key
// needs to be added to the keyring before - this assumes we have defaults, i.e.
// Alice as the key - and this already exists on the test keyring)
const keyring = testKeyring.default();
const adminPair = keyring.getPair(adminId.toString());
// Retrieve the runtime to upgrade
const code = fs.readFileSync('./test.wasm').toString('hex');
const proposal = api.tx.system && api.tx.system.setCode
? api.tx.system.setCode(`0x${code}`) // For newer versions of Substrate
: api.tx.consensus.setCode(`0x${code}`); // For previous versions
console.log(`Upgrading from ${adminId}, ${code.length / 2} bytes`);
// Perform the actual chain upgrade via the sudo module
.signAndSend(adminPair, ({ events = [], status }) => {
console.log('Proposal status:', status.type);
if (status.isInBlock) {
console.error('You have just upgraded your chain');
console.log('Included at block hash', status.asInBlock.toHex());
console.log(JSON.stringify(events.toHuman(), null, 2));
} else if (status.isFinalized) {
console.log('Finalized block hash', status.asFinalized.toHex());
main().catch((error) => {