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DevChain Quick Start

Nethereum includes a full in-process Ethereum node. No Docker, no Geth binary, no external dependencies — just add the NuGet package and start coding.

Install​

dotnet add package Nethereum.DevChain

Basic Usage​

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

// Create an account and start a dev chain
var account = new Account("0xb5b1870957d373ef0eeffecc6e4812c0fd08f554b37b233526acc331bf1544f7");
var devChain = new DevChainNode();
await devChain.StartAsync(account);  // Pre-funds the account with 10,000 ETH

// Create a Web3 instance connected to the in-process node
var web3 = devChain.CreateWeb3(account);

// Use web3 as normal
var balance = await web3.Eth.GetBalance.SendRequestAsync(account.Address);
Console.WriteLine($"Balance: {Web3.Convert.FromWei(balance.Value)} ETH");

// Transfer ETH
var receipt = await web3.Eth.GetEtherTransferService()
    .TransferEtherAndWaitForReceiptAsync("0xde0b295669a9fd93d5f28d9ec85e40f4cb697bae", 1.0m);

Configuration​

var config = new DevChainConfig
{
    ChainId = 1337,
    BlockGasLimit = 30_000_000,
    AutoMine = true,                    // Mine instantly on each transaction
    InitialBalance = BigInteger.Parse("10000000000000000000000")  // 10,000 ETH
};

var devChain = new DevChainNode(config);
await devChain.StartAsync(account);

Multiple Accounts​

// Generate and fund multiple accounts
var accounts = await devChain.GenerateAndFundAccountsAsync(5);

// Or pass specific accounts
var alice = new Account("0x...");
var bob = new Account("0x...");
await devChain.StartAsync(alice, bob);

Factory Methods​

// One-liner: create, configure, and start
var devChain = await DevChainNode.CreateAndStartAsync(account);
var web3 = devChain.CreateWeb3(account);

In-Memory (No SQLite)​

var devChain = DevChainNode.CreateInMemory();
await devChain.StartAsync(account);

Persistent Storage​

// Data survives restarts
var devChain = new DevChainNode(config, "./mychain/chain.db", persistDb: true);
await devChain.StartAsync(account);

Snapshots and Reverts​

var snapshot = await devChain.TakeSnapshotAsync();

// ... do transactions ...

await devChain.RevertToSnapshotAsync(snapshot);  // Undo everything since snapshot

Time Manipulation​

DevChain supports Hardhat/Anvil-compatible time manipulation via RPC:

  • evm_increaseTime — advance the clock
  • evm_setNextBlockTimestamp — set exact timestamp for next block
  • evm_mine — mine a block manually
  • evm_snapshot / evm_revert — state snapshots
  • hardhat_setBalance / hardhat_setCode / hardhat_setNonce — state overrides

HTTP Server​

To expose DevChain as an HTTP endpoint (for MetaMask, Foundry, Hardhat, or any Ethereum tool):

dotnet add package Nethereum.DevChain.Server

Aspire Template​

For a complete dev environment with DevChain + PostgreSQL + Indexer + Explorer:

dotnet new install Nethereum.Aspire.TemplatePack
dotnet new nethereum-devchain -n MyChain
cd MyChain/AppHost && dotnet run