index.ts

import { calculateFee, coins, MsgSendEncodeObject, SigningStargateClient } from "@cosmjs/stargate";
import { DirectSecp256k1HdWallet } from "@cosmjs/proto-signing";
import { TxRaw } from "cosmjs-types/cosmos/tx/v1beta1/tx";
import { MsgMultiSend } from "cosmjs-types/cosmos/bank/v1beta1/tx";
import { Tendermint34Client } from "@cosmjs/tendermint-rpc";

// KYVEs official testnet ("Kaon")
// For mainnet use "kyve-1" as chain-id and "https://rpc-eu-1.kyve.network" as the rpc endpoint
const CHAIN_ID = "kaon-1"
const ENDPOINT = "https://rpc-eu-1.kaon.kyve.network"

// Dummy wallet with 10 $KYVE. In production one should also use a 24 word mnemonic.
// It is also possible creating a wallet without mnemonic and just the private key.
const MNEMONIC = "<enter> <your> <menominc>";

// Account number and sequence can be obtained via
// https://api-eu-1.kaon.kyve.network/cosmos/auth/v1beta1/accounts/kyve17tjql5h3kg2kw5uqngrxz9n4735y7vk3j2d37e
// For mainnet use the mainnet-rpc-endpoint
const ACCOUNT_NUMBER = 7057;
// After successful execution of this script, this number needs to be incremented.
// Otherwise, the script will fail on the next run with account sequence mismatch.
// The current account number can also be obtained via the above query.
let ACCOUNT_SEQUENCE = 4;

(async () => {
  // Offline part
  // To sign messages offline, one needs to obtain the accountNumber and sequence.
  // The accountNumber is unique for every address. The sequence is incremented every time
  // a transaction is mined into a block.
  // Therefore, one needs to manually increment to sequence, everytime a transaction is performed.

  // First, create a wallet out of a mnemonic. The prefix for all KYVE chains is "kyve"
  const wallet = await DirectSecp256k1HdWallet.fromMnemonic(MNEMONIC, {prefix: "kyve"})
  const offlineAccount = (await wallet.getAccounts())[0]

  // Obtain the offline signer
  const client = await SigningStargateClient.offline(wallet, {})

  const fee = calculateFee(200000, "0.02tkyve")
  const signingData = { chainId: CHAIN_ID, sequence: ACCOUNT_SEQUENCE, accountNumber: ACCOUNT_NUMBER }

  // Send 1 $KYVE to yourself using msg multisend
  const sendMsg: any = {
    typeUrl: "/cosmos.bank.v1beta1.MsgMultiSend",
    value: {
      // sum of all inputs needs to match the sum of all outputs
      inputs: [
        {
          address: offlineAccount.address,
          // 1$KYVE = 1,000,000 tkyve
          // For mainnet use ukyve instead
          coins: coins("1000000", "tkyve")
        }
      ],
      outputs: [
        {
          address: offlineAccount.address,
          // 0.5 $KYVE
          coins: coins("500000", "tkyve")
        },
        {
          address: offlineAccount.address,
          // 0.5 $KYVE
          coins: coins("500000", "tkyve")
        }
      ]
    },
  };

  // Build and sign transaction (offline)
  const txRaw = await client.sign(offlineAccount.address, [sendMsg], fee, "offline transaction-1", signingData)
  const txBytes = TxRaw.encode(txRaw).finish();

  // Create broadcast client (this part needs an internet connection)
  const tm_client = await Tendermint34Client.connect(ENDPOINT)
  // Broadcast and print result
  const result = await tm_client.broadcastTxSync({tx: txBytes})
  console.log("Result: ", result)
})();