---
title: Namespace options
description: Scoped to a namespace and its children. Namespace options extend the shared state model beyond global options for hierarchical CLIs. Running myapp storage...
url: https://docs-v3-preview.elastic.dev/argh/advanced/namespace-options
---

# Namespace options
Scoped to a namespace and its children. Namespace options extend the shared state model beyond global options for hierarchical CLIs.

## Registration

```csharp
public record StorageOptions(string ConnectionString = "") : GlobalOptions;

app.MapNamespace<StorageHandlers>("storage", ns =>
{
    ns.UseNamespaceOptions<StorageOptions>();
    ns.Map("list", (StorageOptions o) => { … });
});
```

Running `myapp storage list --connection-string "…" --verbose` applies both the namespace and global flags.

## Inheritance chain

The options type must inherit the parent's options type - `GlobalOptions` at the root, or the enclosing namespace's options further down.
<warning>
  The generator reports an error (**AGH0004**) if the inheritance chain is broken. Each namespace options type must extend its parent's options type.
</warning>

```csharp
public record GlobalOptions(bool Verbose = false);
public record StorageOptions(string ConnectionString = "") : GlobalOptions;
public record BlobOptions(string Container = "") : StorageOptions;

app.UseGlobalOptions<GlobalOptions>();
app.MapNamespace<StorageHandlers>("storage", ns =>
{
    ns.UseNamespaceOptions<StorageOptions>();
    ns.MapNamespace<BlobHandlers>("blob", blob =>
    {
        blob.UseNamespaceOptions<BlobOptions>();
    });
});
```


## Parsing order

<note>
  In generated code, parsing follows this order: globals → namespace options along the path → command flags and positionals.
</note>


## Required parameter injection

Commands under a namespace are required to declare the namespace options type as a parameter. This is enforced by analyzer **AGH0021**.
Annotate the method with `[NoOptionsInjection]` to opt out.

## Combining with `[AsParameters]`

```csharp
public record DeployOptions(string Environment, bool DryRun = false) : StorageOptions;

ns.Map("deploy", ([AsParameters] DeployOptions opts) => { … });
```

Running `myapp storage deploy --connection-string "…" --environment staging --dry-run` passes all inherited and local flags.