evm: line edits

src/technical/evm/nftLayer.md

@@ -2,42 +2,55 @@
 
 This section will explain how to properly interact with the NFT Layer in an EVM ecosystem.
 
+## Configuring the interface
+
+[Here]() is the interface for applications to interact with Wormhole's NFT layer.
+//TODO link to file in github so doesn't become stale
+
+Instantiating the interface will depend on your development ecosystem and blockchain. The Wormhole xAsset contract address is usually stored in your contract address.
+
+Below is an example line of code to instantiate the interface for mainnet Ethereum:
+
+```
+address private wormhole_NFT_bridge_address = address(0x6FFd7EdE62328b3Af38FCD61461Bbfc52F5651fE);
+INFTBridge NFT_bridge = INFTBridge(wormhole_nft_bridge_address);
 ```
-// contracts/NFTBridge.sol
-// SPDX-License-Identifier: Apache 2
 
-pragma solidity ^0.8.0;
+## Transferring a NFT
 
-import "./NFTBridgeGetters.sol";
-import "./NFTBridgeStructs.sol";
+The Wormhole NFT Bridge only supports tokens that support the ERC-721 interface and will create a wrapped NFT with identical metadata. How this is implemented varies by ecosystem.
 
-interface INFTBridge is NFTGetters {
+**Note**: Unlike xAssets, there is no attestation required for bridging NFTs.
 
-    function transferNFT(address token, uint256 tokenID, uint16 recipientChain, bytes32 recipient, uint32 nonce) external payable returns (uint64 sequence);
+To transfer a NFT, there are three steps:
 
-    function completeTransfer(bytes memory encodeVm) external ;
+1. Initiate the NFT transfer
+    - This function call will return a `sequence` (uint64) that is used in the VAA retrieval step
 
-    function encodeTransfer(NFTBridgeStructs.Transfer memory transfer) external pure returns (bytes memory encoded);
-
-    function parseTransfer(bytes memory encoded) external pure returns (NFTBridgeStructs.Transfer memory transfer);
-
-    function onERC721Received(address operator, address, uint256, bytes calldata) external view returns (bytes4);
+```
+transferNFT(tokenAddress, tokenID, recipientChain, recipient, nonce);
+```
 
+2. Retrieve the emitted VAA.
+    - _Note: NFT Transfer VAAs are retrieved from the Guardian Network by the `emitterChainID`, `emitterAddress`, and `sequence`_
+```
+const emitterAddr = getEmitterAddressEth(network.NFTBridgeAddress);
+const seq = parseSequenceFromLogEth(tx, network.bridgeAddress);
+const vaaURL = `${config.wormhole.restAddress}/v1/signed_vaa/${network.wormholeChainId}/${emitterAddr}/${seq}`;
+let vaaBytes = await (await fetch(vaaURL)).json();
+while (!vaaBytes.vaaBytes) {
+  console.log("VAA not found, retrying in 5s!");
+  await new Promise((r) => setTimeout(r, 5000)); //Timeout to let Guardiand pick up log and have VAA ready
+  vaaBytes = await (await fetch(vaaURL)).json();
 }
-
 ```
 
-## Overview
+3.  Complete the NFT transfer
 
-Only ERC-721 supported, creates a wrapped NFT with identical metadata. Implementation varies by ecosystem
+```
+completeTransfer(VAA);
+```
 
-## Sending an NFT
-
-- Unlike xAssets, there is no registration process
-- Code example to send
-
-## Receiving an NFT
-
-- completeTransfer code examples
+## Additional utility
 
 //TODO NFT verification and perhaps some other common usecases

src/technical/evm/xassetLayer.md

@@ -2,7 +2,7 @@
 
 This section will explain how to properly interact with the Wormhome Core Layer in an EVM ecosystem.
 
-# Configuring the interface
+## Configuring the interface
 
 [Here]() is the interface for applications to interact with Wormhole's xAsset layer.
 //TODO link to file in github so doesn't become stale