How to Integrate Front-end Bridges

Network Information

To use an existing Bridge, the first task is to retrieve the Bridge information. You can get the bridge address on a chain from this link:

https://raw.githubusercontent.com/dotoracle/evm-contract-lists/main/networks.json

---

Supported Tokens

You can get the list of supported tokens on a chain from 2 links below

• EVM Chain (for BSC Mainnet - chain id: 56). All supported networks in this repo
• Casper

---

Request Bridge

EVM Chain

To request bridge on EVM Chain, you need to call the requestBridge method in the bridge contract For example:

// use web3.js
import Web3 from 'web3'
import { toHex } from 'web3-utils'
import { useWeb3React } from '@web3-react/core'

const { account, library } = useWeb3React()
const web3 = new Web3(library)

// if the target network is a EVM chain
let encoded = web3.eth.abi.encodeParameters(['string'], [account?.toLowerCase()])

// If the target network is Casper
// accountHash get from
if (targetNetwork.notEVM) {
  encoded = web3.eth.abi.encodeParameters(['string'], [accountHash.toLowerCase()])
}

await bridgeContract.methods
  .requestBridge(
    tokenAddress,
    encoded,
    amount,
    targetNetwork.chainId
  )
  .send({
    chainId: toHex(sourceNetwork.chainId),
    from: account,
    value: amount,
  })

For more details, please refer this file.

---

Casper Network

1. Install: casper-js-sdk casper-js-client-helper

  yarn add casper-js-sdk
  yarn add casper-js-client-helper@https://github.com/dotoracle/casper-js-client-helper

2. Make a Deploy

    import {
      CasperClient,
      CasperServiceByJsonRPC,
      CLPublicKey,
      CLValueBuilder,
      decodeBase16,
      DeployUtil,
      RuntimeArgs,
    } from 'casper-js-sdk'
    import { SafeEventEmitterProvider } from 'casper-js-sdk/dist/services/ProviderTransport'
    import { contractSimpleGetter } from 'casper-js-client-helper/dist/helpers/lib'
   
    const senderKey = CLPublicKey.fromHex(account)
   
    // networkInfo: current network information
    const deployParams = new DeployUtil.DeployParams(senderKey, networkInfo?.key ?? 'casper-test', 1, 1800000)
   
    // selectedToken: token that you want to send
    const contractHash = selectedToken.address
   
    // contractHash: the contract hash that gets from this link (with the corresponding token): https://github.com/dotoracle/casper-contract-hash/blob/master/config.json
    const contractHashAsByteArray = decodeBase16(contractHash)
   
    // Get fee
    const fee = await contractSimpleGetter(networkInfo.rpcURL, contractHash, ['swap_fee'])
   
    const deploy = DeployUtil.makeDeploy(
      deployParams,
      DeployUtil.ExecutableDeployItem.newStoredContractByHash(
        contractHashAsByteArray,
        'request_bridge_back',
        RuntimeArgs.fromMap({
          amount: CLValueBuilder.u256(toPlainString(value)),
          fee: CLValueBuilder.u256(fee),
          to_chainid: CLValueBuilder.u256(targetNetwork.chainId.toString()),
          receiver_address: CLValueBuilder.string(receipient),
          id: CLValueBuilder.string(1),
        }),
      ),
      DeployUtil.standardPayment(400000000),
    )

3. Sign and Send Deploy

    const json = DeployUtil.deployToJson(deploy)
    const casperClient = new CasperClient(networkInfo.rpcURL)
   
    // Sign transaction using casper-signer.
    const signature = await window.casperlabsHelper.sign(json, account)
    const deployObject = DeployUtil.deployFromJson(signature)
   
    if (deployObject.val instanceof DeployUtil.Deploy) {
      deployRes = await casperClient.putDeploy(deployObject.val)
    }

4. For more details, please refer this file.

---

API Endpoints

• Mainnet: https://bridge-mainnet.dotoracle.network/
• Testnet: https://api.dotoracle.network/

Get transaction history of and account:

1. Get all transactions of an account: /transactions/account/chainId. For example: https://api.dotoracle.network/transactions/0x00481E0dE32FecFF1C7ce3AF19cb03E01aFC0e48/42

2. Get all transactions from all accounts: /history[?limit=50&page=1/]. For example: https://api.dotoracle.network/history/

---

Claim assets on target chain (EVM chain)

‼️ Please note, that you only need to claim assets on EVM chains. On Casper Network, our contract will mint & transfer tokens to the account hash that you have entered while requesting bridge success.

1. This is JSON describing the transaction history, you can easily get all informations of a transaction.

    "transactions": [
      {
        "_id": "631983cb526fa6fc80aff3b9",
        "fromChainId": 96945816564243,
        "index": 2,
        "originChainId": 42,
        "originToken": "0x1111111111111111111111111111111111111111",
        "toChainId": 42,
        "account": "0xe68485b880898b5c4cde29d40a588846a5ced582",
        "amount": "49000000000000000",
        "originSymbol": "",
        "requestBlock": 1078222,
        "requestHash": "0x9820cb3198499f57573321a59e8c2ca25413703ec23c1da6a91ac29d63c1d196",
        "requestTime": 1662616272,
        "txCreator": "account-hash-a769093d50eebe829668ce0116cf24da9f17dcfe223bac30e1c33967d5888c71",
        "originDecimals": 18
      },
    ]

2. Request Withdraw by sending a POST request to our API: /request-withdraw.

   Params:

   requestHash: request bridge transaction hash

   fromChainId: source chain Id

   toChainId: target chain Id

   index: transaction index (get from API)

You will get a signature that looks like this

 {
   "r": "0xaa",
   "s": "0xbb",
   "v": "0xcc",
   "name": "BUSD",
   "symbol": "BUSD",
   "decimals": "18"
 }

3. Call claimToken method

  const chainIdData = [originChainId, fromChainId, toChainId, index]

  await bridgeContract.methods
    .claimToken(originToken, account, amount, chainIdData, requestHash, r, s, v, name, symbol, decimals)
    .send({
      chainId: toHex(toChainId),
      from: account,
    })

For more details, please refer this file.