Set Up an IOU-IOU Bridge

(Requires the XChainBridge amendment )

Setting up an IOU-IOU bridge enables you to move tokens between chains.

Note: The code samples on this page illustrate how to bridge a hypotethical "TST" token from Devnet to Sidechain-Devnet, using a supported client library to query and submit transactions.

Prerequisites

An XRP-XRP bridge must be set up between the locking and issuing chain.
Ensure the witnesses' transaction submission accounts are funded on the locking and issuing chains.
Set up an issuer on the issuing chain to mint and burn a wrapped version of the token you want to bridge. See: Issue a Fungible Token

Steps

1. Connect to the locking chain (Devnet) and issuing chain (Sidechain-Devnet).

const xrpl = require('xrpl')

const WS_URL_lockingchain = 'wss://s.devnet.rippletest.net:51233/' // Locking chain
const WS_URL_issuingchain = 'wss://sidechain-net2.devnet.rippletest.net:51233/' // Issuing chain

// Define the XChainBridge, using the "TST" token.
const xchainbridge = {
  "LockingChainDoor": "rn895gh1MHnnAgL4hR9q464PJSFiYwQYcV",
  "LockingChainIssue": {
    "currency": "TST",
    "issuer": "rP9jPyP5kyvFRb6ZiRghAGw5u8SGAmU4bd"
  },
  "IssuingChainDoor": "ra1MsW5s6Qg4NXUAJVKw8f21ZghSYG1DQw", // Use the account issuing the wrapped token
  "IssuingChainIssue": {
    "currency": "TST",
    "issuer": "ra1MsW5s6Qg4NXUAJVKw8f21ZghSYG1DQw"
  }
}

async function main() {
  // Define the network clients.
  const client_lockingchain = new xrpl.Client(WS_URL_lockingchain)
  await client_lockingchain.connect()

  const client_issuingchain = new xrpl.Client(WS_URL_issuingchain)
  await client_issuingchain.connect()

  // ... custom code goes here

  // Disconnect when done (If you omit this, Node.js won't end the process)
  await client_lockingchain.disconnect()
  await client_issuingchain.disconnect()
}

main()

2. Submit an `XChainCreateBridge` transaction from the door account on the locking chain.

Don't include a MinAccountCreateAmount value.

  const wallet_lockingchain = xrpl.Wallet.fromSeed('s████████████████████████████') // Locking chain door account
  const xchaincreatebridge_lockingchain = await client_lockingchain.submitAndWait({
    "TransactionType": "XChainCreateBridge",
    "Account": wallet_lockingchain.address,
    "XChainBridge": xchainbridge,
  "SignatureReward": 200
  }, {autofill: true, wallet: wallet_lockingchain})

3. Submit a `SignerListSet` transaction from the door account on the locking chain.

  const signerlistset_lockingchain = await client_lockingchain.submitAndWait({
    "TransactionType": "SignerListSet",
    "Account": wallet_lockingchain.address,
    "Fee": "12",
    "SignerQuorum": 2,    
    // Use the witness servers' submitting accounts on the locking chain.
    "SignerEntries": [
        {
            "SignerEntry": {
                "Account": "rsA2LpzuawewSBQXkiju3YQTMzW13pAAdW",
                "SignerWeight": 1
            }
        },
        {
            "SignerEntry": {
                "Account": "rUpy3eEg8rqjqfUoLeBnZkscbKbFsKXC3v",
                "SignerWeight": 1
            }
        }
    ]
  }, {autofill: true, wallet: wallet_lockingchain})

4. Disable the master key on the locking chain's door account with an `AccountSet` transaction.

const disablekey_lockingchain = await client_lockingchain.submitAndWait({
    "TransactionType": "AccountSet",
    "Account": wallet_lockingchain.address,
    "SetFlag": 4
  }, {autofill: true, wallet: wallet_lockingchain})

5. Submit an `XChainCreateBridge` transaction from the door account on the issuing chain.

Don't include a MinAccountCreateAmount value.

  const wallet_issuingchain = xrpl.Wallet.fromSeed('s████████████████████████████') // The account issuing the wrapped token
  const xchaincreatebridge_issuingchain = await client_issuingchain.submitAndWait({
    "TransactionType": "XChainCreateBridge",
    "Account": wallet_issuingchain.address,
    "XChainBridge": xchainbridge,
  "SignatureReward": 200
  }, {autofill: true, wallet: wallet_issuingchain})

6. Submit a `SignerListSet` transaction from the door account on the issuing chain.

  const signerlistset_issuingchain = await client_issuingchain.submitAndWait({
    "TransactionType": "SignerListSet",
    "Account": wallet_issuingchain.address,
    "Fee": "12",
    "SignerQuorum": 2,    
    // Use the witness servers' submitting accounts on the issuing chain.
    "SignerEntries": [
        {
            "SignerEntry": {
                "Account": "rD323VyRjgzzhY4bFpo44rmyh2neB5d8Mo",
                "SignerWeight": 1
            }
        },
        {
            "SignerEntry": {
                "Account": "rJMfWNVbyjcCtds8kpoEjEbYQ41J5B6MUd",
                "SignerWeight": 1
            }
        }
    ]
  }, {autofill: true, wallet: wallet_issuingchain})

7. Disable the master key on the issuing chain's door account with an `AccountSet` transaction.

const disablekey_issuingchain = await client_issuingchain.submitAndWait({
    "TransactionType": "AccountSet",
    "Account": wallet_issuingchain.address,
    "SetFlag": 4
  }, {autofill: true, wallet: wallet_issuingchain})

Set Up an IOU-IOU Bridge

Prerequisites

Steps

1. Connect to the locking chain (Devnet) and issuing chain (Sidechain-Devnet).

2. Submit an XChainCreateBridge transaction from the door account on the locking chain.

3. Submit a SignerListSet transaction from the door account on the locking chain.

4. Disable the master key on the locking chain's door account with an AccountSet transaction.

5. Submit an XChainCreateBridge transaction from the door account on the issuing chain.

6. Submit a SignerListSet transaction from the door account on the issuing chain.

7. Disable the master key on the issuing chain's door account with an AccountSet transaction.