---
title: Namespace roots
description: Map namespace prefixes to generated output folders.
---


A namespace root pins a namespace as the base of the output folder hierarchy and places its output under a named base folder. When a type's namespace equals a configured root or starts with that root followed by a dot, the root prefix is stripped and the remainder is placed under the specified folder.

This is an alternative to [`CratisProxiesSegmentsToSkip`](/arc/backend/csharp/proxy-generation/configuration/basic/#namespace-segment-skipping) that works by name rather than by a fixed segment count, making it more resilient when namespace depths vary across a project.

## Configuration

```xml
<ItemGroup>
    <NamespaceRoot Include="features" Namespace="MyApp.Features" Folder="features" />
</ItemGroup>
```

| Attribute | Description |
| --- | --- |
| `Include` | MSBuild item identity; the generator reads the metadata below, not this name |
| `Namespace` | The C# namespace prefix to match |
| `Folder` | Output base folder; an empty value intentionally strips the namespace prefix without adding a folder |

**Example:** With namespace root `MyApp.Features` → `features`:

| C# namespace | Output folder |
| --- | --- |
| `MyApp.Features.Auth.Registration` | `features/Auth/Registration/` |
| `MyApp.Features.Billing.Invoices` | `features/Billing/Invoices/` |
| `MyApp.Features.Auth` | `features/Auth/` |
| `MyApp.Features` | `features/` |
| `MyApp.Other` | _(falls back to segment-skip logic — namespace root does not apply)_ |

## Multiple roots

You can declare multiple roots. The longest matching namespace wins:

```xml
<ItemGroup>
    <NamespaceRoot Include="features" Namespace="MyApp.Features" Folder="features" />
    <NamespaceRoot Include="shared" Namespace="MyApp.SharedTypes" Folder="shared" />
</ItemGroup>
```

## Priority

Namespace roots **only take effect for types whose namespace matches the root**. Types that do not match any configured root fall back to `CratisProxiesSegmentsToSkip` as normal.

These XML blocks belong inside the existing project's `Project` element. Namespace roots affect **output folders only**, not conventional API routes.

## CLI

With the [executable alias prerequisite](/arc/backend/csharp/proxy-generation/configuration/output-behavior/#direct-executable), pass one or more `--namespace-root` flags using `=` to separate the namespace from the folder:

```bash
proxygenerator assembly.dll output-path --skip-output-deletion \
  --namespace-root=MyApp.Features=features \
  --namespace-root=MyApp.SharedTypes=shared
```