---
title: Native AOT and trimming
description: Nullean.Argh is AOT-safe and trimming-safe by default. The source generator emits all parsing, routing, dispatch, and help code directly into your assembly...
url: https://docs-v3-preview.elastic.dev/argh/features/aot
---

# Native AOT and trimming
Nullean.Argh is AOT-safe and trimming-safe by default. The source generator emits all parsing, routing, dispatch, and help code directly into your assembly at build time. No reflection, no dynamic dispatch.

## Guarantees

- **No reflection** - all type binding, parameter parsing, and dispatch is generated as static C# code
- **No dynamic dispatch** - the generated switch tree routes directly to handler methods
- **Trimming-safe** - no hidden dependencies that the trimmer might remove
- **AOT-compatible** - works with `PublishAot=true` without any special configuration


## DI and AOT

When using `Nullean.Argh.Hosting` with native AOT, register handler and middleware types explicitly in DI so required constructors are preserved:
```csharp
builder.Services.AddScoped<DeployCommands>();
builder.Services.AddSingleton<AuditMiddleware>();
builder.Services.AddArgh(args, b =>
{
    b.MapScoped<DeployCommands>();
    b.UseMiddleware<AuditMiddleware>(ServiceLifetime.Singleton);
});
```


## Lambda handlers

<warning>
  Lambda handlers (`UseMiddleware` inline delegates) are the one exception to the zero-reflection rule and emit warning **AGH0006**. Prefer method groups or class registration for AOT-published apps.
</warning>


## CI validation

The project includes an `aot-validate` CI job that publishes with Native AOT on Linux, macOS, and Windows and invokes `__schema` on the native binary to verify correct operation.

## Generated code target

Generated code targets `netstandard2.0` (no `System.Linq`, no pattern features beyond what that TFM allows). The static extension methods in `ArghTypeBindingExtensions.g.cs` require C# 14 preview (`static extension` members).