Getting started

⚠️ JavaScript SDK is in beta

Install module

Using NPM:

npm install @hop-protocol/v2-sdk

Using Yarn:

yarn add @hop-protocol/v2-sdk

CDN

jsDeliver CDN:

<script src="https://cdn.jsdelivr.net/npm/@hop-protocol/v2-sdk@latest/hop.js"></script>

unpkg CDN:

<script src="https://unpkg.com/@hop-protocol/v2-sdk@latest/hop.js"></script>

Import module

Import as ES6 module (e.g. Using TypeScript, babel, webpack):

import { Hop } from '@hop-protocol/v2-sdk'

Import as commonJS module (e.g. Using Node.js directly or no ES6 modules):

const { Hop } = require('@hop-protocol/v2-sdk')

Instantiate SDK

import { Hop } from '@hop-protocol/v2-sdk'

const hop = new Hop('goerli')

Avaiable networks are only goerli at this time.

Send Message

Send a message from one chain to another chain.

Use this method to get the populated transaction for sending a message.

Method: getSendMessagePopulatedTx

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const fromChainId = 420
  const toChainId = 5
  const toAddress = "0x5f335A890bbB5Cd1a4a7f7A1C8F9F6F75efDCA89"
  const toCalldata = "0x812448a5000000000000000000000000000000000000000000000000000000000000002a"

  const hop = new Hop('goerli')
  const txData = await hop.getSendMessagePopulatedTx({
    fromChainId,
    toChainId,
    toAddress,
    toCalldata
  })
  console.log(txData)
}

main().catch(console.error)

Get Bundle Proof

Get bundle proof needed to relay message at destination chain.

Use this method to get the bundle proof JSON.

Method: getBundleProofFromMessageId

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const fromChainId = 420
  const toChainId = 5
  const messageId = "0xe8e4885871d370ef17693db9fc0f34bda218c8685a9bb3ab40648cf8d2a5358e"

  const hop = new Hop('goerli')
  const bundleProof = await hop.getBundleProofFromMessageId({
    fromChainId,
    messageId
  })
  console.log(bundleProof)
}

main().catch(console.error)

Relay Message

Relay and execute message at the destination

Use this method to get the populated transaction for relaying a message.

Method: getRelayMessagePopulatedTx

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const fromChainId = 420
  const toChainId = 5
  const fromAddress = "0x9997da3de3ec197C853BCC96CaECf08a81dE9D69"
  const toAddress = "0x5f335A890bbB5Cd1a4a7f7A1C8F9F6F75efDCA89"
  const toCalldata = "0x812448a5000000000000000000000000000000000000000000000000000000000000002a"
  const bundleProof = {
    "bundleId": "0x5e26c4282d410e7e0c892561566ce0a6522f4762de1fc59d9bfba068890d9f7d",
    "treeIndex": 2,
    "siblings": [
      "0xb93f64fa408f10085138ba6ea27c42d5832869d6c1c6667c25c022cdeaf03390"
    ],
    "totalLeaves": 3
  }

  const hop = new Hop('goerli')
  const txData = await hop.getRelayMessagePopulatedTx({
    fromChainId,
    toChainId,
    fromAddress,
    toAddress,
    toCalldata,
    bundleProof
  })
  console.log(txData)
}

main().catch(console.error)

Exit Bundle

Exit bundle at the destination.

Use this method to get the populated transaction for exiting a bundle.

Method: getBundleExitPopulatedTx

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const fromChainId = 420
  const bundleCommittedTransactionHash = "0xf7aa4bccf0ffe34d76ceb1f18864a2dbfd590bdfca44ad29a316079559327020"

  const hop = new Hop('goerli')
  const txData = await hop.getBundleExitPopulatedTx({
    fromChainId,
    bundleCommittedTransactionHash
  })
  console.log(txData)
}

main().catch(console.error)

Get Message ID

Get Message ID from transaction hash.

Method: getMessageIdFromTransactionHash

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const fromChainId = 420
  const transactionHash = "0xdccaf2fc42186d66f72869ecb12b0be1f9b9c018a43a13f4ff32ee3eaa0d943c"

  const hop = new Hop('goerli')
  const messageId = await hop.getMessageIdFromTransactionHash({
    fromChainId,
    transactionHash
  })
  console.log(messageId)
}

main().catch(console.error)

Get Message Calldata

Get calldata of message given message ID

Method: getMessageCalldata

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const fromChainId = 420
  const messageId = "0xf672a68db7ebbac6e28bc217967a83d5fc63f0f185a9c25b1693a3afb445a696"

  const hop = new Hop('goerli')
  const calldata = await hop.getMessageCalldata({
    fromChainId,
    messageId
  })
  console.log(calldata)
}

main().catch(console.error)

Get Message Sent Event

Get full event log from message ID

Method: getMessageSentEventFromMessageId

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const fromChainId = 420
  const messageId = "0xf672a68db7ebbac6e28bc217967a83d5fc63f0f185a9c25b1693a3afb445a696"

  const hop = new Hop('goerli')
  const event = await hop.getMessageSentEventFromMessageId({
    fromChainId,
    messageId
  })
  console.log(event)
}

main().catch(console.error)

Get Message Fee

Get fee in wei required to send message

Method: getMessageFee

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const hop = new Hop('goerli')
  const fromChainId = 420
  const toChainId = 5

  const fee = await hop.getMessageFee({
    fromChainId,
    toChainId
  })
  console.log(fee)
}

main().catch(console.error)

Get Events

Get decoded events for hub and spoke contracts.

Method: getEvents

Parameters

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const eventNames = ["MessageSent", "MessageBundled"]
  const chainId = 420
  const fromBlock = 4554675
  const toBlock = 4555675

  const hop = new Hop('goerli')
  const events = await hop.getEvents({
    eventNames,
    chainId,
    fromBlock,
    toBlock
  })
  console.log(events)
}

main().catch(console.error)

Set Contract Addresses

Set contract addresses config for sdk

Method: setContractAddresses

Parameters

Response

void

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const contractAddresses = {
  "5": {
    "chainId": 5,
    "startBlock": 8095954,
    "hubCoreMessenger": "0xE3F4c0B210E7008ff5DE92ead0c5F6A5311C4FDC",
    "spokeCoreMessenger": "0xE3F4c0B210E7008ff5DE92ead0c5F6A5311C4FDC",
    "ethFeeDistributor": "0xf6eED903Ac2A34E115547874761908DD3C5fe4bf"
  },
  "420": {
    "chainId": 420,
    "startBlock": 3218800,
    "spokeCoreMessenger": "0xeA35E10f763ef2FD5634dF9Ce9ad00434813bddB",
    "connector": "0x6be2E6Ce67dDBCda1BcdDE7D2bdCC50d34A7eD24"
  }
}

  const hop = new Hop('goerli')
  hop.setContractAddresses(contractAddresses)
}

main().catch(console.error)

Get Contract Addresses

Get hub and spoke contract addresses sdk is using.

Method: getContractAddresses

Parameters

None

Response

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const hop = new Hop('goerli')
  const contractAddresses = await hop.getContractAddresses()
  console.log(contractAddresses)
}

main().catch(console.error)

Set RPC Providers

Set custom RPC Providers config

Method: setRpcProviders

Parameters

Response

void

Example

import { Hop } from '@hop-protocol/v2-sdk'

async function main() {
  const rpcProviders = {
  "5": "https://goerli.infura.io/v3/84842078b09946638c03157f83405213",
  "420": "https://goerli.optimism.io"
}

  const hop = new Hop('goerli')
  hop.setRpcProviders(rpcProviders)
}

main().catch(console.error)

More examples

If you'd like to see more examples or have any feedback, message us on Discord!

SDK API Reference

Contract addresses