Neon Token Transfer library for JavaScript clients

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TL;DR

The package using on our NeonPass codebase.

• React demo available.

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Installation and setup

Firstly, install the package:

yarn add @neonevm/token-transfer-core
# or
npm install @neonevm/token-transfer-core

For using with ethers.js we recommend additional using @neonemv/token-transfer-ethers

yarn add @neonevm/token-transfer-ethers
# or
npm install @neonevm/token-transfer-ethers

For native

Upon installation, it is essential to provide certain mandatory properties when initializing a new instance to ensure proper functionality. When integrating this into your frontend application, it's necessary to grant Solana/Neon wallets access for signing and sending transactions across Solana and Neon EVM networks.

const solanaWallet = `<Your Solana wallet public key>`;
const neonWallet = `<Your Neon wallet public address>`;

We employ the evmParams method from Neon EVM to obtain specific addresses and constants required for seamless operations.

Additional for Multi-token gas fee, we added new method (nativeTokenList) for getting native token for special NeonEvm chain.

const neonNeonEvmUrl = `https://devnet.neonevm.org`;
const solNeonEvmUrl = `https://devnet.neonevm.org/solana/sol`;
const solanaUrl = `https://api.devnet.solana.com`;
const neonProxyApi = new NeonProxyRpcApi(neonNeonEvmUrl);
const solProxyApi = new NeonProxyRpcApi(solNeonEvmUrl);
// nativeTokenList returns the native token list for every chain network, first will be NEON, second SOL
const [neonNativeToken, solNativeToken] = await neonProxyApi.nativeTokenList(); // get native tokens for chain networks
const neonProxyStatus = await neonProxyApi.evmParams(); // get evm params config
const solProxyStatus = await solProxyApi.evmParams();

// for NEON token native network
const neonChainId = Number(neonNativeToken.tokenChainId);
const neonTokenMint = new PublicKey(neonNativeToken.tokenMint);
const neonEvmProgram = new PublicKey(neonProxyStatus.neonEvmProgramId);

// for SOL token native network
const solChainId = Number(solNativeToken.tokenChainId);
const solTokenMint = new PublicKey(solNativeToken.tokenMint);
const solEvmProgram = new PublicKey(solProxyStatus.neonEvmProgramId);

Still, for testing you can use NEON_TRANSFER_CONTRACT_DEVNET or NEON_TRANSFER_CONTRACT_MAINNET constants. This objects contains snapshots with latest neonProxyStatus state.

Transfer NEON transactions

To generate a transaction for transferring NEON from Solana to Neon EVM, utilize the functions found in the neon-transfer.ts file.

const neonToken: SPLToken = {
  address: '',
  decimals: NEON_TOKEN_MINT_DECIMALS,
  name: 'Neon',
  symbol: 'NEON',
  logoURI: 'https://raw.githubusercontent.com/neonlabsorg/token-list/main/neon_token_md.png',
  address_spl: neonTokenMint.toBase58(),
  chainId: neonChainId
};
const solToken: SPLToken = {
  name: 'Solana SOL',
  symbol: 'SOL',
  logoURI: 'https://raw.githubusercontent.com/neonlabsorg/token-list/master/assets/solana-sol-logo.svg',
  address: '1111111111',
  address_spl: solTokenMint.toBase58(),
  chainId: solChainId
};

// for transfer NEON: Solana -> NeonEvm (NEON chain)
const transaction = await solanaNEONTransferTransaction({ 
  solanaWallet, 
  neonWallet, 
  neonEvmProgram, 
  neonTokenMint,
  token: neonToken, 
  amount,
  chainId: neonChainId 
}); // Solana Transaction object
transaction.recentBlockhash = (await connection.getLatestBlockhash('finalized')).blockhash; // Network blockhash
const signature = await connection.sendRawTransaction(transaction.serialize()); // method for sign and send transaction to network

// for transfer SOL: Solana -> NeonEvm (SOL chain)
const transaction = await solanaSOLTransferTransaction({
  connection,
  solanaWallet, 
  neonWallet,
  neonEvmProgram: solEvmProgram,
  neonTokenMint: solTokenMint,
  splToken: solToken, 
  amount,
  chainId: solChainId 
}); // Solana Transaction object
transaction.recentBlockhash = (await connection.getLatestBlockhash('finalized')).blockhash; // Network blockhash
const signature = await connection.sendRawTransaction(transaction.serialize()); // method for sign and send transaction to network

And for transfer NEON from Neon EVM to Solana, you should know token contract address, you can look it in this file.

const tokenContract = NEON_TRANSFER_CONTRACT_DEVNET; // or SOL_TRANSFER_CONTRACT_DEVNET
const transaction = await neonNeonTransactionEthers({ 
  provider, 
  from: neonWallet.address, 
  to: tokenContract, 
  solanaWallet, 
  amount 
}); // Neon EVM Transaction object
const signedTrx = await neonWallet.signTransaction(transaction);
if (signedTrx?.rawTransaction) {
  const txResult = neonWallet.sendSignedTransaction(signedTrx.rawTransaction);
  txResult.on('transactionHash', (hash: string) => console.log(hash));
  txResult.on('error', (error: Error) => console.error(error));
}

Transfer ERC20 transactions

When working with Devnet, Testnet, or Mainnet, different ERC20 tokens are utilized. We have compiled a token-list containing the tokens supported and available on Neon EVM. For further information, please refer to our documentation.

For transfer ERC20 tokens from Solana to Neon EVM, using this patterns:

import tokenList from 'token-list/tokenlist.json';

const proxyUrl = `https://devnet.neonevm.org`;
const tokens = tokenList.tokens.filter((token) => token.chainId === CHAIN_ID);
const token = tokens[0];
//The wallet signer from ethers.js, used for signing the transaction.
const walletSigner = new Wallet(keccak256(Buffer.from(`${neonWallet.address.slice(2)}${solanaWallet.publicKey.toBase58()}`, 'utf-8')), new JsonRpcProvider(proxyUrl));

const transaction = await neonTransferMintTransactionEthers({ 
  connection, 
  proxyApi, 
  neonEvmProgram/* or solEvmProgram*/, 
  solanaWallet,
  neonWallet: neonWallet.address,
  walletSigner,
  splToken: token, 
  amount,
  chainId: neonChainId /*or solChainId*/ 
});
transaction.recentBlockhash = (await connection.getLatestBlockhash()).blockhash;
const signature = await connection.sendRawTransaction(transaction.serialize());

And for transfer ERC20 tokens from Neon EVM to Solana:

import tokenList from 'token-list/tokenlist.json';

const tokens = tokenList.tokens.filter((token) => token.chainId === CHAIN_ID);
const mintPubkey = new PublicKey(token.address_spl);
const associatedToken = getAssociatedTokenAddressSync(mintPubkey, solanaWallet);
const solanaTransaction = createAssociatedTokenAccountTransaction({ 
  solanaWallet,
  tokenMint: mintPubkey, 
  associatedToken,
  neonHeapFrame: proxyStatus.NEON_HEAP_FRAME 
});
solanaTransaction.recentBlockhash = (await connection.getLatestBlockhash()).blockhash;
const neonTransaction = await createMintNeonTransactionEthers({ 
  provider,
  neonWallet: neonWallet.address, 
  associatedToken,
  splToken: token, 
  amount
});
const solanaSignature = await connection.sendRawTransaction(transaction.serialize());
const neonSignature = await neonWallet.signTransaction(transaction);
const txResult = neonWallet.sendSignedTransaction(neonSignature.rawTransaction);

Within the Neon Transfer codebase, we employ the web3.js library to streamline our code. However, if the situation demands, you can opt for alternatives such as ethers.js or WalletConnect.

For React

To incorporate it into your React App, please refer to our React Demo located in the examples/react/neon-transfer-react folder. Or see live demo.

For Testing

We have provided extra examples within the src/__tests__/e2e folder, intended for testing and debugging this library on both the Devnet Solana network and Neon EVM.

Run this command for e2e testing Neon Transfer code.

yarn test
# or
npm run test

Building Docs

We can run TypeDoc with packages mode to generate a single docs folder in the root of the project.

# We need to build before building the docs so that `foo` can reference types from `bar`
# TypeDoc can't use TypeScript's build mode to do this for us because build mode may skip
# a project that needs documenting, or include packages that shouldn't be included in the docs
yarn build
# or
npm run build

Now you can run docs generation script.

yarn docs
# or
npm run docs