---
title: 'ARC0003: Handle() must be on [Command] type'
---

## Rule

Public `Handle()` methods that operate on a `[Command]` type must be declared on the command type itself.

## Severity

Error

## Example

### Violation

```csharp
using Cratis.Arc.Commands.ModelBound;

[Command]
public record CreateOrder(string OrderId);

public class CreateOrderHandler
{
    // ARC0003: Handle() for CreateOrder is not on the command type itself
    public void Handle(CreateOrder command)
    {
    }
}
```

### Fix

```csharp
using Cratis.Arc.Commands.ModelBound;

[Command]
public record CreateOrder(string OrderId)
{
    public void Handle()
    {
    }
}
```