This quick start will help you set up a minimal Argus indexer in just a few minutes.

---

Prerequisites

• .NET 9.0 SDK or later
• PostgreSQL database
• Entity Framework Core

---

Step 1: Create Project & Install Packages

# Create a new project
dotnet new webapi -n ArgusQuickStart
cd ArgusQuickStart

# Install packages
dotnet add package Argus.Sync --version 0.3.1-alpha
dotnet add package Microsoft.EntityFrameworkCore.Design
dotnet add package Npgsql.EntityFrameworkCore.PostgreSQL

---

Step 2: Add Minimal Code

Create these three files:

BlockInfo.cs - Your blockchain data model

using Argus.Sync.Data.Models;

public record BlockInfo(
    string Hash,      // Block identifier
    ulong Number,     // Block height
    ulong Slot,       // Slot number
    DateTime CreatedAt // Timestamp
) : IReducerModel;

MyDbContext.cs - Database access layer

using Argus.Sync.Data;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;

public class MyDbContext(DbContextOptions options, IConfiguration configuration)
    : CardanoDbContext(options, configuration)
{
    public DbSet<BlockInfo> Blocks => Set<BlockInfo>();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Entity<BlockInfo>(e => e.HasKey(b => b.Hash));
    }
}

BlockReducer.cs - Data transformation logic

using Argus.Sync.Reducers;
using Chrysalis.Cbor.Types.Cardano.Core;
using Microsoft.EntityFrameworkCore;

public class BlockReducer(IDbContextFactory<MyDbContext> dbContextFactory)
    : IReducer<BlockInfo>
{
    // Called when processing new blocks
    public async Task RollForwardAsync(Block block)
    {
        using var db = dbContextFactory.CreateDbContext();
        db.Blocks.Add(new BlockInfo(
            block.Header().Hash(),
            block.Header().HeaderBody().BlockNumber(),
            block.Header().HeaderBody().Slot(),
            DateTime.UtcNow
        ));
        await db.SaveChangesAsync();
    }

    // Called during chain reorganizations
    public async Task RollBackwardAsync(ulong slot)
    {
        using var db = dbContextFactory.CreateDbContext();
        db.Blocks.RemoveRange(db.Blocks.Where(b => b.Slot >= slot));
        await db.SaveChangesAsync();
    }
}

---

Step 3: Configuration

Replace appsettings.json with:

{
  "ConnectionStrings": {
    // Database settings
    "CardanoContext": "Host=localhost;Database=argus;Username=postgres;Password=password;Port=5432",
    "CardanoContextSchema": "cardanoindexer"
  },
  "CardanoNodeConnection": {
    // Blockchain connection (using gRPC for simplicity)
    "ConnectionType": "gRPC",
    "gRPC": {
      "Endpoint": "https://cardano-preview.utxorpc-m1.demeter.run",
      "ApiKey": "your_api_key"
    },
    "NetworkMagic": 2 // Preview testnet magic
  },
  "Sync": {
    // Dashboard settings
    "Dashboard": {
      "TuiMode": true,
      "RefreshInterval": 5000
    }
  }
}

Replace Program.cs with:

using Argus.Sync.Extensions;

// Build the application
var builder = WebApplication.CreateBuilder(args);

// Register Argus services
builder.Services.AddCardanoIndexer<MyDbContext>(builder.Configuration);
builder.Services.AddReducers<MyDbContext, IReducerModel>(builder.Configuration);

// Launch!
var app = builder.Build();
app.Run();

---

Step 4: Run

# Create and apply migrations
dotnet ef migrations add Initial
dotnet ef database update

# Start the indexer
dotnet run

When successfully running, you'll see the Argus dashboard:

---

What's Next?

• Learn about advanced Configuration Options