UA Custom Configuration Overview

User Application contracts may set their own configuration for block confirmation, send version, relayer, oracle, etc.

When a UA wishes to configure their own block confirmations both the outboundBlockConfirmations of the source and the inboundBlockConfirmations of the destination must be configured and match.

How to Configure

A User Application (UA) can use non-default protocol settings, and to do so it must implement the interface ILayerZeroUserApplicationConfig. The UA may then manually update its ApplicationConfig . See examples below as well as the CONFIG_TYPES.

This function would be implemented in your UA. This is included in LZapp.sol if you inherit from it.

function setConfig(
    uint16 _version,
    uint16 _chainId,
    uint _configType,
    bytes calldata _config
) external override onlyOwner {
    lzEndpoint.setConfig(_version, _chainId, _configType, _config);
}

Config Types

Type	Value
CONFIG_TYPE_INBOUND_PROOF_LIBRARY_VERSION	1
CONFIG_TYPE_INBOUND_BLOCK_CONFIRMATIONS	2
CONFIG_TYPE_RELAYER	3
CONFIG_TYPE_OUTBOUND_PROOF_TYPE	4
CONFIG_TYPE_OUTBOUND_BLOCK_CONFIRMATIONS	5
CONFIG_TYPE_ORACLE	6

info

The config should be abi encoded.

ethers.utils.defaultAbiCoder.encode([configValueType], [newValue]);

Set: Inbound Proof Library

Config	Definition
1	MPT
2	Feather Proof

let config = ethers.utils.defaultAbiCoder.encode(['uint16'], [inboundProofLibraryVersion]);
await UA.setConfig(0, dstChainId, CONFIG_TYPE_INBOUND_PROOF_LIBRARY_VERSION, config);

info

CONFIG_TYPE_INBOUND_PROOF_LIBRARY_VERSION is 1 in this casse

Set: Inbound Block Confirmations

Config	Definition
42	How many block confirmations is needed for inbound block confirmations

let config = ethers.utils.defaultAbiCoder.encode(['uint16'], [42]);
await UA.setConfig(0, dstChainId, CONFIG_TYPE_INBOUND_BLOCK_CONFIRMATIONS, config);

Set: Relayer

Config	Definition
relayerAddr	Which relayer you want to use

let config = ethers.utils.solidityPack(['address'], [relayerAddr]);
await UA.setConfig(0, dstChainId, CONFIG_TYPE_RELAYER, config);

Set: Outbound Proof Type/LibraryVersion

Config	Definition
1	MPT
2	Feather Proof

let config = ethers.utils.defaultAbiCoder.encode(['uint16'], [outboundProofType]);
await UA.setConfig(0, dstChainId, CONFIG_TYPE_OUTBOUND_PROOF_TYPE, config);

Set: Outbound Block Confirmations

Config	Definition
42	How many block confirmations is needed for outbound block confirmations

let config = ethers.utils.defaultAbiCoder.encode(
  ['uint16'],
  [17], // outbound block confirmations
);
await UA.setConfig(0, dstChainId, CONFIG_TYPE_OUTBOUND_BLOCK_CONFIRMATIONS, config);

Set: Oracle

Config	Definition
Oracle Address	Which oracle to use

The available oracles can be found here. (Select the oracle type you prefer)

Oracle settings are configured per channel pathway, meaning UAs who want to lock Oracle configs will need to call setConfig per chain pairing.

let config = ethers.utils.defaultAbiCoder.encode(['address'], [oracleAddr]);
await UA.setConfig(0, dstChainId, CONFIG_TYPE_ORACLE, config);