import FungibleToken from 0xa0225e7000ac82a9 import NonFungibleToken from 0xb6763b4399a888c8 import ViewResolver from 0xb6763b4399a888c8 import MetadataViews from 0xb6763b4399a888c8 import FlowToken from 0x4445e7ad11568276 import ScopedFTProviders from 0x715c57f7a59bc39b import EVM from 0xb6763b4399a888c8 import FlowEVMBridge from 0x715c57f7a59bc39b import FlowEVMBridgeConfig from 0x715c57f7a59bc39b import FlowEVMBridgeUtils from 0x715c57f7a59bc39b /// Bridges an NFT from the signer's collection in Cadence to the signer's COA in FlowEVM /// /// NOTE: This transaction also onboards the NFT to the bridge if necessary which may incur additional fees /// than bridging an asset that has already been onboarded. /// /// @param nftContractAddress: The Flow account address hosting the NFT-defining Cadence contract /// @param nftContractName: The name of the NFT-defining Cadence contract /// @param id: The Cadence NFT.id of the NFT to bridge to EVM /// transaction(nftContractAddress: Address, nftContractName: String, id: UInt64) { let nft: @{NonFungibleToken.NFT} let coa: auth(EVM.Bridge) &EVM.CadenceOwnedAccount let requiresOnboarding: Bool let scopedProvider: @ScopedFTProviders.ScopedFTProvider prepare(signer: auth(CopyValue, BorrowValue, IssueStorageCapabilityController, PublishCapability, SaveValue) &Account) { /* --- Reference the signer's CadenceOwnedAccount --- */ // // Borrow a reference to the signer's COA self.coa = signer.storage.borrow(from: /storage/evm) ?? panic("Could not borrow COA from provided gateway address") /* --- Retrieve the NFT --- */ // // Borrow a reference to the NFT collection, configuring if necessary let viewResolver = getAccount(nftContractAddress).contracts.borrow<&{ViewResolver}>(name: nftContractName) ?? panic("Could not borrow ViewResolver from NFT contract") let collectionData = viewResolver.resolveContractView( resourceType: nil, viewType: Type() ) as! MetadataViews.NFTCollectionData? ?? panic("Could not resolve NFTCollectionData view") let collection = signer.storage.borrow( from: collectionData.storagePath ) ?? panic("Could not access signer's NFT Collection") // Withdraw the requested NFT & calculate the approximate bridge fee based on NFT storage usage let currentStorageUsage = signer.storage.used self.nft <- collection.withdraw(withdrawID: id) let withdrawnStorageUsage = signer.storage.used var approxFee = FlowEVMBridgeUtils.calculateBridgeFee( bytes: currentStorageUsage - withdrawnStorageUsage ) * 1.10 // Determine if the NFT requires onboarding - this impacts the fee required self.requiresOnboarding = FlowEVMBridge.typeRequiresOnboarding(self.nft.getType()) ?? panic("Bridge does not support this asset type") if self.requiresOnboarding { approxFee = approxFee + FlowEVMBridgeConfig.onboardFee } /* --- Configure a ScopedFTProvider --- */ // // Issue and store bridge-dedicated Provider Capability in storage if necessary if signer.storage.type(at: FlowEVMBridgeConfig.providerCapabilityStoragePath) == nil { let providerCap = signer.capabilities.storage.issue( /storage/flowTokenVault ) signer.storage.save(providerCap, to: FlowEVMBridgeConfig.providerCapabilityStoragePath) } // Copy the stored Provider capability and create a ScopedFTProvider let providerCapCopy = signer.storage.copy>( from: FlowEVMBridgeConfig.providerCapabilityStoragePath ) ?? panic("Invalid Provider Capability found in storage.") let providerFilter = ScopedFTProviders.AllowanceFilter(approxFee) self.scopedProvider <- ScopedFTProviders.createScopedFTProvider( provider: providerCapCopy, filters: [ providerFilter ], expiration: getCurrentBlock().timestamp + 1.0 ) } execute { if self.requiresOnboarding { // Onboard the NFT to the bridge FlowEVMBridge.onboardByType( self.nft.getType(), feeProvider: &self.scopedProvider as auth(FungibleToken.Withdraw) &{FungibleToken.Provider} ) } // Execute the bridge self.coa.depositNFT( nft: <-self.nft, feeProvider: &self.scopedProvider as auth(FungibleToken.Withdraw) &{FungibleToken.Provider} ) // Destroy the ScopedFTProvider destroy self.scopedProvider } }

🎶Happy diving into the flow

Transaction

🎶Happy diving into the flow