aspire-devchain

Development

Help users create and run a local Ethereum development environment with .NET Aspire — DevChain node, blockchain indexer, Blazor explorer, and PostgreSQL. Use this skill when the user mentions Aspire DevChain template, nethereum-devchain, creating a local blockchain environment with Aspire, setting up DevChain with an explorer and indexer, or wants a single-command Ethereum dev environment with .NET. Also trigger when users mention dotnet new nethereum-devchain or Nethereum.Aspire.TemplatePack.

QUICK START

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Nethereum DevChain Aspire Template

The nethereum-devchain template creates a complete local Ethereum development environment orchestrated by .NET Aspire — a DevChain node, blockchain indexer, Blazor explorer, and PostgreSQL database, all wired together with service discovery, telemetry, and health checks.

When to Use This

Setting up a local Ethereum development environment quickly
Need a blockchain explorer for local development
Want an indexed local chain (blocks, transactions, token transfers in PostgreSQL)
Replacing Docker Compose setups for Ethereum dev infrastructure
Setting up infrastructure before building a dApp (see aspire-dapp for full-stack)

Install & Create

# Install the template pack (once)
dotnet new install Nethereum.Aspire.TemplatePack

# Create a project
dotnet new nethereum-devchain -n MyChain
cd MyChain

# Set the dev account private key
cd AppHost
dotnet user-secrets set "Parameters:devAccountPrivateKey" "5de4111afa1a4b94908f83103eb1f1706367c2e68ca870fc3fb9a804cdab365a"
cd ..

# Run
dotnet run --project AppHost

The Aspire dashboard opens at https://localhost:17178 with all services visible.

Template Parameters

dotnet new nethereum-devchain -n MyChain \
    --NethereumVersion 6.1.0 \
    --ChainId 42069 \
    --AspireVersion 13.1.1

Parameter	Default	Description
`--NethereumVersion`	`6.1.0`	Nethereum NuGet package version
`--ChainId`	`31337`	Chain ID for the DevChain
`--AspireVersion`	`13.1.1`	.NET Aspire SDK version

What's Included

Service	Description
DevChain	In-memory Ethereum node (EIP-1559, debug tracing, pre-funded accounts)
Indexer	Indexes blocks, transactions, token transfers (ERC-20/721/1155), MUD records into PostgreSQL
Explorer	Blazor blockchain explorer with contract interaction, ABI decoding, wallet connection
PostgreSQL	Managed Docker container for all indexed data

Project Structure

MyChain/
├── AppHost/          Aspire orchestrator
├── DevChain/         Ethereum node
├── Indexer/          Block indexer → PostgreSQL
├── Explorer/         Blazor blockchain explorer
└── ServiceDefaults/  Shared Aspire config

Prerequisites

.NET 10 SDK or later
Docker Desktop (for PostgreSQL)

Configuration

DevChain Storage

{
  "DevChain": {
    "ChainId": 31337,
    "Storage": "sqlite",
    "AutoMine": true
  }
}

Set "Storage": "memory" for ephemeral chains that reset on restart.

Connect Tools

// Nethereum
var web3 = new Web3("http://localhost:<port>");
var balance = await web3.Eth.GetBalance.SendRequestAsync("0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266");

# Foundry
cast balance 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 --rpc-url http://localhost:<port>

Troubleshooting

PostgreSQL unhealthy: docker volume rm nethereum-pgdata then restart
Port conflicts: Aspire assigns dynamic ports — check the dashboard

Related Skills

devchain — DevChain library details (configuration, forking, RPC methods, testing patterns)
aspire-dapp — Full-stack dApp template (adds WebApp, Solidity contracts, wallet integration)
blockchain-explorer — Explorer features in depth
blockchain-indexing — Indexer configuration and customisation

For full documentation, see: https://docs.nethereum.com/docs/aspire-templates/guide-devchain-template