XChainCreateBridge

Attention

Cross-chain bridges functionality is part of the proposed XLS-38d extension (Not Enabled) to the XRP Ledger protocol. There isn't an official amendment yet. Until there is an amendment, the details documented on these pages are subject to change frequently. [Source]

Please use this form to report bugs, provide feedback, or share network issues you experience.

[Source]

The XChainCreateBridge transaction creates a new Bridge ledger object and defines a new cross-chain bridge entrance on the chain that the transaction is submitted on. It includes information about door accounts and assets for the bridge.

The transaction must be submitted first by the locking chain door account. To set up a valid bridge, door accounts on both chains must submit this transaction, in addition to setting up witness servers.

The complete production-grade setup would also include a SignerListSet transaction on the two door accounts for the witnesses’ signing keys, as well as disabling the door accounts’ master key. This ensures that the witness servers are truly in control of the funds.

Note: Each door account can only have one bridge. This prevents the creation of duplicate bridges for the same asset, which can cause asset imbalances on either chain.

Example XChainCreateBridge JSON

{
  "TransactionType": "XChainCreateBridge",
  "Account": "rhWQzvdmhf5vFS35vtKUSUwNZHGT53qQsg",
  "XChainBridge": {
    "LockingChainDoor": "rhWQzvdmhf5vFS35vtKUSUwNZHGT53qQsg",
    "LockingChainIssue": {
      "currency": "XRP"
    },
    "IssuingChainDoor": "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh",
    "IssuingChainIssue": {
      "currency": "XRP"
    }
  },
  "SignatureReward": 200,
  "MinAccountCreateAmount": 1000000
}

XChainCreateBridge Fields

Field	JSON Type	Internal Type	Required?	Description
`MinAccountCreateAmount`	`Currency Amount`	`AMOUNT`	No	The minimum amount, in XRP, required for a `XChainAccountCreateCommit` transaction. If this isn't present, the `XChainAccountCreateCommit` transaction will fail. This field can only be present on XRP-XRP bridges.
`SignatureReward`	`Currency Amount`	`AMOUNT`	Yes	The total amount to pay the witness servers for their signatures. This amount will be split among the signers.
`XChainBridge`	`XChainBridge`	`XCHAIN_BRIDGE`	Yes	The bridge (door accounts and assets) to create.

XChainBridge Fields

Field	JSON Type	Internal Type	Required?	Description
`IssuingChainDoor`	`string`	`ACCOUNT`	Yes	The door account on the issuing chain. For an XRP-XRP bridge, this must be the genesis account (the account that is created when the network is first started, which contains all of the XRP).
`IssuingChainIssue`	`Issue`	`ISSUE`	Yes	The asset that is minted and burned on the issuing chain. For an IOU-IOU bridge, the issuer of the asset must be the door account on the issuing chain, to avoid supply issues.
`LockingChainDoor`	`string`	`ACCOUNT`	Yes	The door account on the locking chain.
`LockingChainIssue`	`Issue`	`ISSUE`	Yes	The asset that is locked and unlocked on the locking chain.

XCHAIN_BRIDGE Field Type

XCHAIN_BRIDGE is a new field type introduced by XLS-38d.

Type Name	Type Code	Bit Length	Length-prefixed?	Description
`XCHAIN_BRIDGE`	25	Variable	No	A bridge between two blockchains, identified by the door accounts and issued assets on the locking chain and issuing chain. `XCHAIN_BRIDGE` is serialized in this order: locking chain door, locking chain issue, issuing chain door, issuing chain issue.