Get Started on Neon EVM

note

This is a bare bones Get Started; alternatively browse the full support available in this site.

Get test NEON for Neon Devnet

To populate the accounts with test NEON, visit the faucet, where you will be issued up to 100 NEON.

Configure Neon network credentials in your framework's config file

Hardhat

The network credentials are configured under the “networks” property in the hardhat.config.js.

Devnet

neondevnet: {
      url: "https://devnet.neonevm.org",
      accounts: [Array_of_accounts_private_keys],
      chainId: 245022926,
      allowUnlimitedContractSize: false,
      gas: "auto",
      gasPrice: "auto",
      isFork: true,
},

Mainnet

neonmainnet: {
      url: "https://neon-proxy-mainnet.solana.p2p.org",
      accounts: [Array_of_accounts_private_keys],
      chainId: 245022934,
      allowUnlimitedContractSize: false,
      gas: "auto",
      gasPrice: "auto",
      isFork: true,
},

See the Hardhat tutorial

Foundry

Foundry doesn’t have a configuration file like Hardhat or Truffle to configure the network settings. Rather, the RPC endpoint and the private key are specified in the command line when passing foundry commands.

See the Foundry tutorial.

Truffle

The network credentials can be configured under the “networks” property in the truffle-config.js.

Devnet

neondevnet: {
      provider: () => {
        return new HDWalletProvider(
          [Array_of_accounts_private_keys],
          "https://devnet.neonevm.org",
        );
      },
      network_id: 245022926
},

Mainnet

neondevnet: {
      provider: () => {
        return new HDWalletProvider(
          [Array_of_accounts_private_keys],
          "https://neon-proxy-mainnet.solana.p2p.org",
        );
      },
      network_id: 245022934
},

See the Truffle tutorial.

Verify contracts on Neon Devnet with Hardhat and NeonScan:

To verify contracts on Neon Devnet with NeonScan, add this configuration to hardhat.config.js:

etherscan: {
  apiKey: {
    neonevm: "test"
  },
  customChains: [
    {
      network: "neonevm",
      chainId: 245022926,
      urls: {
        apiURL: "https://devnet-api.neonscan.org/hardhat/verify",
        browserURL: "https://devnet.neonscan.org"
      }
    }
  ]
}

The command for verifying a deployed contract is:

npx hardhat verify <DEPLOYED_CONTRACT_ADDRESS> --network neondevnet

Follow this GitHub tutorial for Hardhat contract verification.

Gotchas

Reaching account limits

You may encounter an error The transaction requires too lot of accounts, i.e. that the transaction has exceeded the account limit. This error refers to the fact that the transaction on Solana does not allow the number of accounts to be more than 64. If you do need more than 64 accounts, the smart contract function throwing the error needs to be optimized.

Basic optimization of smart contracts

Consider applying the following optimization techniques:

1. Reduce the contract binary size.
2. Use indexed parameters for the events.
3. Use custom errors instead of require statements whenever possible.
4. Minimize function calls from within a function (this reduces the function call overload).
5. Avoid using strings as storage values and, instead, use fixed-sized bytes32 whenever possible.
6. Avoid loops through long arrays and use mappings instead of loops.
7. Make revert and assert messages as short as possible.
8. Write a library for all the reusable codes.
9. Use memory locations wisely - calldata, memory, storage (order is cheapest to expensive).
10. Variables should be declared in order so that they use fewer storage slots.

Learn more about optimizations from the EVM Compatibility Overview.