unity-quickstart

Unity Integration

Integrate Ethereum into Unity games. Nethereum provides Unity-compatible libraries with the async Web3 API (preferred) and coroutine wrappers, WebGL wallet connectivity (EIP-6963 multi-wallet, MetaMask), and typed contract services.

When to Use This Skill

• Building a Unity game that reads or writes blockchain data
• Connecting browser wallets in Unity WebGL builds
• Deploying or interacting with smart contracts from Unity
• Querying ERC-20/ERC-721 token balances in a game

Installation

Add to Packages/manifest.json:

{
  "scopedRegistries": [
    {
      "name": "package.openupm.com",
      "url": "https://package.openupm.com",
      "scopes": ["com.nethereum.unity"]
    }
  ],
  "dependencies": {
    "com.nethereum.unity": "5.0.0",
    "com.unity.nuget.newtonsoft-json": "3.2.1"
  }
}

Important notes:

• WebGL + async/await requires WebGLThreadingPatcher package
• For IL2CPP builds: set IL2CPP Code Generation to Faster (smaller) builds in Player Settings

Query Block Number (Async — Preferred)

using UnityEngine;
using Nethereum.Web3;
using Nethereum.Unity.Rpc;
using System;

public class GetBlockNumber : MonoBehaviour
{
    public string Url = "https://ethereum-rpc.publicnode.com";

    async void Start()
    {
        var web3 = new Web3(new UnityWebRequestRpcTaskClient(new Uri(Url)));
        var blockNumber = await web3.Eth.Blocks.GetBlockNumber.SendRequestAsync();
        Debug.Log(
quot;Block: {blockNumber.Value}");
    }
}

UnityWebRequestRpcTaskClient uses Unity's UnityWebRequest for HTTP — required for WebGL builds.

Send ETH (Desktop/Mobile)

using Nethereum.Web3;
using Nethereum.Web3.Accounts;

var account = new Account("0xYOUR_PRIVATE_KEY", chainId: 31337);
var web3 = new Web3(account, "http://localhost:8545");

var receipt = await web3.Eth.GetEtherTransferService()
    .TransferEtherAndWaitForReceiptAsync("0xRecipient", 0.1m);
Debug.Log(
quot;TX: {receipt.TransactionHash}");

WebGL: EIP-6963 Multi-Wallet Discovery (Recommended)

EIP-6963 discovers all installed browser wallets — MetaMask, Rainbow, Coinbase, etc.:

using Nethereum.Unity.EIP6963;
using Nethereum.EIP6963WalletInterop;

var walletProvider = EIP6963WebglHostProvider.CreateOrGetCurrentInstance();

// Discover all installed wallets
var wallets = await walletProvider.GetAvailableWalletsAsync();
foreach (var wallet in wallets)
    Debug.Log(
quot;Found: {wallet.Name} ({wallet.Rdns})");

// Select and connect
if (wallets.Length > 0)
{
    await walletProvider.SelectWalletAsync(wallets[0].Uuid);
    var account = await walletProvider.EnableProviderAsync();
    Debug.Log(
quot;Connected: {account}");

    // Get Web3 — wallet handles signing
    var web3 = await walletProvider.GetWeb3Async();
    var balance = await web3.Eth.GetBalance.SendRequestAsync(walletProvider.SelectedAccount);
    Debug.Log(
quot;Balance: {Web3.Convert.FromWei(balance.Value)} ETH");
}

Listen to Account/Network Changes

Events use Func<T, Task> delegates — handlers must return Task:

walletProvider.SelectedAccountChanged += async (newAccount) =>
{
    Debug.Log(
quot;Account switched: {newAccount}");
    return;  // implicit Task.CompletedTask
};

walletProvider.NetworkChanged += async (newChainId) =>
{
    Debug.Log(
quot;Network switched: {newChainId}");
    return;
};

WebGL: MetaMask Direct (Fallback)

using Nethereum.Unity.Metamask;

var metamask = MetamaskWebglHostProvider.CreateOrGetCurrentInstance();
await metamask.EnableProviderAsync();
var web3 = await metamask.GetWeb3Async();

var receipt = await web3.Eth.GetEtherTransferService()
    .TransferEtherAndWaitForReceiptAsync("0xRecipient", 0.1m);

ERC-20 Token Interaction

Use built-in typed services — no ABI or code generation needed:

var erc20 = web3.Eth.ERC20.GetContractService(tokenAddress);

var name = await erc20.NameQueryAsync();
var symbol = await erc20.SymbolQueryAsync();
var decimals = await erc20.DecimalsQueryAsync();
var balance = await erc20.BalanceOfQueryAsync(ownerAddress);

Debug.Log(
quot;{name} ({symbol}): {Web3.Convert.FromWei(balance, decimals)}");

Similarly, web3.Eth.ERC721 and web3.Eth.ERC1155 provide typed access to NFT and multi-token contracts.

Cross-Platform Architecture

Use conditional compilation to handle WebGL vs desktop:

private async Task<IWeb3> GetWeb3Async()
{
#if UNITY_WEBGL
    var walletProvider = EIP6963WebglHostProvider.CreateOrGetCurrentInstance();
    await walletProvider.EnableProviderAsync();
    return await walletProvider.GetWeb3Async();
#else
    var account = new Account(privateKey, chainId);
    return new Web3(account, url);
#endif
}

Once you have IWeb3, all web3.Eth.* calls work identically regardless of platform.

Code Generation (Shared Projects)

Generate typed C# contract services from Solidity ABI:

dotnet tool install -g Nethereum.Generator.Console

Nethereum.Generator.Console generate from-abi \
    -abi ./out/MyToken.abi \
    -bin ./out/MyToken.bin \
    -o ./SharedContracts \
    -ns MyGame.Contracts \
    -cn MyToken

Share the generated code between Unity and .NET test projects using a netstandard2.0 project with package.json + .asmdef files. Reference from Unity via file: dependency in manifest.json.

Platform Support

Resources

• Unity3d Sample Template — complete starter project
• WebGLThreadingPatcher — async/await for WebGL

For full documentation, see: https://docs.nethereum.com/docs/unity/overview