MsgBroadcaster Transaction

The MsgBroadcaster abstraction class is a way to broadcast transactions on Injective with ease. With it, you can pass a Message that you want to be packed in a transaction and the signer's address and the transaction will be prepared, signed, and broadcasted.

An example of usage can be found on our Helix demo repo. As for the messages that you can pass to the broadcast methods, you can find examples in the Core Modules section of the docs.

MsgBroadcaster + Wallet Strategy

This MsgBroadcaster is used alongside the Wallet Strategy class for building decentralized applications.

To instantiate (and use) the MsgBroadcaster class, you can use the following code snippet

import { MsgSend } from "@injectivelabs/sdk-ts";
import { toChainFormat } from "@injectivelabs/utils";
import { MsgBroadcaster } from "@injectivelabs/wallet-core";
import { ChainId, EvmChainId } from "@injectivelabs/ts-types";
import { WalletStrategy } from "@injectivelabs/wallet-strategy";
import { Network, getNetworkEndpoints } from "@injectivelabs/networks";

const chainId = ChainId.Testnet; // The Injective Testnet Chain ID
const evmChainId = EvmChainId.TestnetEvm; // The Injective Evm Testnet Chain ID

export const alchemyRpcEndpoint = `https://eth-goerli.alchemyapi.io/v2/${process.env.APP_ALCHEMY_SEPOLIA_KEY}`;

export const walletStrategy = new WalletStrategy({
  chainId,
  evmOptions: {
    evmChainId,
    rpcUrl: alchemyRpcEndpoint,
  },
});

export const msgBroadcaster = new MsgBroadcaster({
  walletStrategy,
  simulateTx: true,
  network: Network.Testnet,
  endpoints: getNetworkEndpoints(Network.Testnet),
  gasBufferCoefficient: 1.1,
})(
  // Usage Example
  async () => {
    const signer = "inj1...";

    const msg = MsgSend.fromJSON({
      amount: {
        denom: "inj",
        amount: toChainFormat(0.01).toFixed(),
      },
      srcInjectiveAddress: signer,
      dstInjectiveAddress: "inj1...",
    });

    // Prepare + Sign + Broadcast the transaction using the Wallet Strategy
    await msgBroadcastClient.broadcast({
      injectiveAddress: signer,
      msgs: msg,
    });
  }
)();

Constructor/Broadcast Options

We allow to override some of the options passed to the constructor of MsgBroadcaster as well as when broadcasting the transaction. Here is the interface and the meaning of each field

import { Msgs } from '@injectivelabs/sdk-ts'
import { ChainId } from '@injectivelabs/ts-types'
import { Network, NetworkEndpoints } from '@injectivelabs/networks'
import type { WalletStrategy } from '../strategies'

export interface MsgBroadcasterOptions {
  network: Network /** network configuration (chainId, fees, etc) - Network.MainnetSentry for mainnet or  Network.TestnetSentry for testnet */
  endpoints?: NetworkEndpoints /** optional - overriding the endpoints taken from the `network` param **/
  feePayerPubKey?: string /** optional - if you are using the fee delegation service, you can set the fee payer so you don't do an extra query to the Web3Gateway */
  simulateTx?: boolean /** simulate the transaction before broadcasting + get gas fees needed for the transaction */
  txTimeout?: number /** optional - blocks to wait for tx to be included in a block **/
  walletStrategy: WalletStrategy
  gasBufferCoefficient?: number /** optional - as gas buffer to add to the simulated/hardcoded gas to ensure the transaction is included in a block */
}

export interface MsgBroadcasterTxOptions {
  memo?: string /** MEMO added to the transaction **/
  injectiveAddress: string /** the signer of the transaction **/
  msgs: Msgs | Msgs[] /** the messages to pack into a transaction **/

  /*
  *** overriding the hardcoded gas/simulation -
  *** depending on the simulateTx parameter in
  *** the MsgBroadcaster constructor
  */
  gas?: {
    gasPrice?: string
    gas?: number /** gas limit */
    feePayer?: string
    granter?: string
  }
}

```

{% hint style="info" %} To override the endpoints and use your infrastructure (which is something we recommend), please read more on the Networks page on the endpoints you need to provide and how to set them up. {% endhint %}

MsgBroadcaster with Private Key

This MsgBroadcaster is used with a private key (mostly used for CLI environments). Constructor/broadcast options are quite similar as for the MsgBroadcaster.

import { toChainFormat } from "@injectivelabs/utils";
import { MsgSend, MsgBroadcasterWithPk } from "@injectivelabs/sdk-ts";

export const msgBroadcasterWithPk = new MsgBroadcasterWithPk({
  privateKey: `0x...` /** private key hash or PrivateKey class from sdk-ts */,
  network: NETWORK,
})(
  // Usage Example
  async () => {
    const signer = "inj1...";

    const msg = MsgSend.fromJSON({
      amount: {
        denom: "inj",
        amount: toChainFormat(0.01).toFixed(),
      },
      srcInjectiveAddress: signer,
      dstInjectiveAddress: "inj1...",
    });

    // Prepare + Sign + Broadcast the transaction using the Wallet Strategy
    await msgBroadcasterWithPk.broadcast({
      injectiveAddress: signer,
      msgs: msg,
    });
  }
)();