### Start HttpRepl connected to localhost example

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/web-api/http-repl/index.md

Example command starting HttpRepl connected to a specific base URL.

```console
httprepl https://localhost:5001
```

--------------------------------

### Start HttpRepl

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/web-api/http-repl/index.md

Starts the HttpRepl tool in the terminal after installation.

```console
httprepl
```

--------------------------------

### Start Nginx service

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/host-and-deploy/linux-nginx.md

Start the Nginx daemon explicitly after installing it for the first time.

```bash
sudo service nginx start
```

--------------------------------

### Connect command example in HttpRepl

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/web-api/http-repl/index.md

Example of connecting to a local web API from a disconnected HttpRepl session.

```console
(Disconnected)> connect https://localhost:5001
```

--------------------------------

### WebHost.Start(string url, RequestDelegate app)

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/web-host.md

Initializes and starts a WebHost with default configurations, a specified listening URL, and a custom RequestDelegate handler.

```APIDOC
## WebHost.Start(string url, RequestDelegate app)

### Description
Runs the host with a specified URL and a `RequestDelegate`.

### Signature
```csharp
public static IWebHost Start(string url, RequestDelegate app)
```

### Parameters
- **url** (`string`) - Required - The URL the server should listen on (e.g., `"http://localhost:8080"`).
- **app** (`RequestDelegate`) - Required - The request delegate handler used to process incoming requests.

### Usage Example
```csharp
using (var host = WebHost.Start("http://localhost:8080", app => app.Response.WriteAsync("Hello, World!")))
{
    Console.WriteLine("Use Ctrl-C to shutdown the host...");
    host.WaitForShutdown();
}
```
```

--------------------------------

### WebHost.StartWith(Action<IApplicationBuilder> app)

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/web-host.md

Runs the web host by starting with a delegate that configures an IApplicationBuilder. By default, the application listens on http://localhost:5000.

```APIDOC
## WebHost.StartWith(Action<IApplicationBuilder> app)

### Description
Runs the host by starting with a delegate that configures an `IApplicationBuilder`. The host listens on `http://localhost:5000` by default.

### Signature
```csharp
public static IWebHost StartWith(Action<IApplicationBuilder> app)
```

### Parameters
- **app** (`Action<IApplicationBuilder>`) - A delegate to configure the application's request pipeline.

### Usage Example
```csharp
using (var host = WebHost.StartWith(app => 
    app.Use(next => 
    {
        return async context => 
        {
            await context.Response.WriteAsync("Hello World!");
        };
    })))
{
    Console.WriteLine("Use Ctrl-C to shut down the host...");
    host.WaitForShutdown();
}
```
```

--------------------------------

### Install Homebrew on macOS

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/mobile/native-mobile-backend.md

Installs Homebrew on macOS via Terminal if it is not already present. Follow the instructions presented by the installer to complete setup.

```Bash
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
```

--------------------------------

### WebHost.Start(RequestDelegate app)

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/web-host.md

Initializes and starts a WebHost with default configurations and a custom RequestDelegate. Runs listening on default URL http://localhost:5000.

```APIDOC
## WebHost.Start(RequestDelegate app)

### Description
Initializes and starts a new host with preconfigured defaults using a `RequestDelegate` handler without requiring a separate `Startup` class.

### Signature
```csharp
public static IWebHost Start(RequestDelegate app)
```

### Parameters
- **app** (`RequestDelegate`) - Required - The request delegate handler used to process incoming requests.

### Usage Example
```csharp
using (var host = WebHost.Start(app => app.Response.WriteAsync("Hello, World!")))
{
    Console.WriteLine("Use Ctrl-C to shutdown the host...");
    host.WaitForShutdown();
}
```
```

--------------------------------

### Inject host services into the Startup constructor

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/startup.md

Demonstrates injecting IConfiguration and IWebHostEnvironment into the Startup class constructor.

```csharp
public class Startup
{
    private readonly IWebHostEnvironment _env;

    public Startup(IConfiguration configuration, IWebHostEnvironment env)
    {
        Configuration = configuration;
        _env = env;
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        if (_env.IsDevelopment())
        {
        }
        else
        {
        }
    }
}
```

--------------------------------

### Response from GET /api/todoitems

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/tutorials/first-web-api.md

Example JSON response returned when calling the GET /api/todoitems endpoint.

```json
[
  {
    "id": 1,
    "name": "walk dog",
    "isComplete": true
  }
]
```

--------------------------------

### Configure hosting startup assemblies via WebHostDefaults.HostingStartupAssembliesKey

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/platform-specific-configuration.md

Applies hosting startup assemblies programmatically using UseSetting on the web host builder. The Configure methods run in the order assemblies are listed.

```csharp
public static IHostBuilder CreateHostBuilder(string[] args) =>
    Host.CreateDefaultBuilder(args)
        .ConfigureWebHostDefaults(webBuilder =>
        {
            webBuilder.UseSetting(
                    WebHostDefaults.HostingStartupAssembliesKey, 
                    "{ASSEMBLY1;ASSEMBLY2; ...}")
                .UseStartup<Startup>();
        });
```

--------------------------------

### GET /api/books response example

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/tutorials/first-mongo-app/includes/first-mongo-app-9.md

Displays the JSON array response received when executing a GET request on /api/books.

```json
[
  {
    "Id": "61a6058e6c43f32854e51f51",
    "Name": "Design Patterns",
    "Price": 54.93,
    "Category": "Computers",
    "Author": "Ralph Johnson"
  },
  {
    "Id": "61a6058e6c43f32854e51f52",
    "Name": "Clean Code",
    "Price": 43.15,
    "Category": "Computers",
    "Author": "Robert C. Martin"
  }
]
```

--------------------------------

### WebHost.StartWith(string url, Action<IApplicationBuilder> app)

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/web-host.md

Runs the web host by starting with a specified URL and a delegate that configures an IApplicationBuilder. The application responds on the custom URL provided.

```APIDOC
## WebHost.StartWith(string url, Action<IApplicationBuilder> app)

### Description
Runs the host by starting with a specific URL and a delegate that configures an `IApplicationBuilder`.

### Signature
```csharp
public static IWebHost StartWith(string url, Action<IApplicationBuilder> app)
```

### Parameters
- **url** (`string`) - The URL prefix on which the host should listen (e.g., `http://localhost:8080`).
- **app** (`Action<IApplicationBuilder>`) - A delegate to configure the application's request pipeline.

### Usage Example
```csharp
using (var host = WebHost.StartWith("http://localhost:8080", app => 
    app.Use(next => 
    {
        return async context => 
        {
            await context.Response.WriteAsync("Hello World!");
        };
    })))
{
    Console.WriteLine("Use Ctrl-C to shut down the host...");
    host.WaitForShutdown();
}
```
```

--------------------------------

### Response from GET /api/todoitems/{id}

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/tutorials/first-web-api.md

Example JSON response returned when calling the GET /api/todoitems/{id} endpoint for a specific ID.

```json
{
  "id": 1,
  "name": "walk dog",
  "isComplete": true
}
```

--------------------------------

### Configure Startup.Configure in ASP.NET Core 2.2

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/migration/22-to-30.md

Example showing Startup.Configure in an ASP.NET Core 2.2 application using UseSignalR and UseMvc.

```csharp
public void Configure(IApplicationBuilder app)
{
    ...

    app.UseStaticFiles();

    app.UseAuthentication();

    app.UseSignalR(hubs =>
    {
        hubs.MapHub<ChatHub>("/chat");
    });

    app.UseMvc(routes =>
    {
        routes.MapRoute("default", "{controller=Home}/{action=Index}/{id?}");
    });
}
```

--------------------------------

### Example Azure AD and Downstream API appsettings.json Configuration

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/blazor/security/blazor-web-app-with-entra.md

Example JSON configuration showing populated Azure AD and Downstream API properties with concrete GUIDs and endpoints.

```json
"AzureAd": {
  "CallbackPath": "/signin-oidc",
  "ClientId": "00001111-aaaa-2222-bbbb-3333cccc4444",
  "Domain": "contoso.onmicrosoft.com",
  "Instance": "https://login.microsoftonline.com/",
  "ResponseType": "code",
  "TenantId": "aaaabbbb-0000-cccc-1111-dddd2222eeee"
},
"DownstreamApi": {
  "BaseUrl": "https://localhost:7277",
  "Scopes": ["api://11112222-bbbb-3333-cccc-4444dddd5555/Weather.Get"]
}
```

--------------------------------

### WebHost.Start(string url, Action<IRouteBuilder> routeBuilder)

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/web-host.md

Initializes and starts a WebHost configured with a specified URL and routing middleware using an IRouteBuilder action.

```APIDOC
## WebHost.Start(string url, Action<IRouteBuilder> routeBuilder)

### Description
Runs the host by starting with a specific URL and an instance of `IRouteBuilder`.

### Signature
```csharp
public static IWebHost Start(string url, Action<IRouteBuilder> routeBuilder)
```

### Parameters
- **url** (`string`) - Required - The URL the server should listen on (e.g., `"http://localhost:8080"`).
- **routeBuilder** (`Action<IRouteBuilder>`) - Required - Action to configure routing paths and handlers.

### Usage Example
```csharp
using (var host = WebHost.Start("http://localhost:8080", router => router
    .MapGet("hello/{name}", (req, res, data) => 
        res.WriteAsync($"Hello, {data.Values["name"]}!"))
    .MapGet("buenosdias/{name}", (req, res, data) => 
        res.WriteAsync($"Buenos dias, {data.Values["name"]}!"))
    .MapGet("throw/{message?}", (req, res, data) => 
        throw new Exception((string)data.Values["message"] ?? "Uh oh!"))
    .MapGet("{greeting}/{name}", (req, res, data) => 
        res.WriteAsync($"{data.Values["greeting"]}, {data.Values["name"]}!"))
    .MapGet("", (req, res, data) => res.WriteAsync("Hello, World!"))))
{
    Console.WriteLine("Use Ctrl-C to shut down the host...");
    host.WaitForShutdown();
}
```
```

--------------------------------

### GET /api/books/{id} response example

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/tutorials/first-mongo-app/includes/first-mongo-app-9.md

Displays the JSON object returned when requesting a single book by ID.

```json
{
  "Id": "61a6058e6c43f32854e51f52",
  "Name": "Clean Code",
  "Price": 43.15,
  "Category": "Computers",
  "Author": "Robert C. Martin"
}
```

--------------------------------

### Sample TenantId and VaultUri values for appsettings.json

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/blazor/security/webassembly/standalone-with-identity/account-confirmation-and-password-recovery.md

Example showing a configured TenantId GUID and Azure Key Vault URI with a trailing slash.

```json
"TenantId": "00001111-aaaa-2222-bbbb-3333cccc4444",
"VaultUri": "https://contoso.vault.azure.net/"
```

--------------------------------

### WebHost.Start(Action<IRouteBuilder> routeBuilder)

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/web-host.md

Initializes and starts a WebHost configured with routing middleware using an IRouteBuilder action.

```APIDOC
## WebHost.Start(Action<IRouteBuilder> routeBuilder)

### Description
Runs the host by starting with an instance of `IRouteBuilder` (Microsoft.AspNetCore.Routing), which uses routing middleware.

### Signature
```csharp
public static IWebHost Start(Action<IRouteBuilder> routeBuilder)
```

### Parameters
- **routeBuilder** (`Action<IRouteBuilder>`) - Required - Action to configure routing paths and handlers.

### Usage Example
```csharp
using (var host = WebHost.Start(router => router
    .MapGet("hello/{name}", (req, res, data) => 
        res.WriteAsync($"Hello, {data.Values["name"]}!"))
    .MapGet("buenosdias/{name}", (req, res, data) => 
        res.WriteAsync($"Buenos dias, {data.Values["name"]}!"))
    .MapGet("throw/{message?}", (req, res, data) => 
        throw new Exception((string)data.Values["message"] ?? "Uh oh!"))
    .MapGet("{greeting}/{name}", (req, res, data) => 
        res.WriteAsync($"{data.Values["greeting"]}, {data.Values["name"]}!"))
    .MapGet("", (req, res, data) => res.WriteAsync("Hello, World!"))))
{
    Console.WriteLine("Use Ctrl-C to shutdown the host...");
    host.WaitForShutdown();
}
```
```

--------------------------------

### Example URL with SearchString query parameter

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/data/ef-rp/sort-filter-page.md

Displays the resulting query string generated when submitting the search form using an HTTP GET method.

```browser-address-bar
https://localhost:5001/Students?SearchString=an
```

--------------------------------

### Configure hosting startup assemblies with HostingStartupAssembliesKey

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/generic-host.md

Passes a semicolon-delimited list of hosting startup assemblies to load alongside the application assembly during startup.

```csharp
webBuilder.UseSetting(WebHostDefaults.HostingStartupAssembliesKey, "assembly1;assembly2");
```

--------------------------------

### Run WebHost with WebHost.StartWith(Action<IApplicationBuilder>)

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/web-host.md

Runs the host using a delegate that configures an IApplicationBuilder, listening on http://localhost:5000 by default. WaitForShutdown blocks until SIGINT/SIGTERM is received.

```csharp
using (var host = WebHost.StartWith(app => 
    app.Use(next => 
    {
        return async context => 
        {
            await context.Response.WriteAsync("Hello World!");
        };
    })))
{
    Console.WriteLine("Use Ctrl-C to shut down the host...");
    host.WaitForShutdown();
}
```

--------------------------------

### Example DataProtection configuration with versionless Azure Key Vault key

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/blazor/security/blazor-web-app-with-entra.md

Example DataProtection section demonstrating Azure Blob Storage and Azure Key Vault endpoints. The key identifier is versionless without a trailing GUID key version to support automatic key rotation.

```json
"DataProtection": {
  "BlobUri": "https://contoso.blob.core.windows.net/data-protection/keys.xml",
  "KeyIdentifier": "https://contoso.vault.azure.net/keys/data-protection"
}
```

--------------------------------

### Create a new React app with Vite

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/client-side/dotnet-on-webworkers.md

Scaffolds a React app with Vite and installs dependencies for .NET 11 or later setups. Select React and JavaScript when prompted.

```bash
npm create vite@latest react-app
cd react-app
npm install
```

--------------------------------

### Start WebHost with URL and RequestDelegate

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/web-host.md

Initializes and runs the host with default configuration and a RequestDelegate listening specifically on http://localhost:8080.

```csharp
using (var host = WebHost.Start("http://localhost:8080", app => app.Response.WriteAsync("Hello, World!")))
{
    Console.WriteLine("Use Ctrl-C to shutdown the host...");
    host.WaitForShutdown();
}
```

--------------------------------

### Switch to BookstoreDb database with use

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/tutorials/first-mongo-app/includes/first-mongo-app3-5.md

Creates the BookstoreDb database if it does not exist, or opens its connection for transactions if it already exists.

```console
use BookstoreDb
```

--------------------------------

### Set Microsoft Entra Authority and ClientId Example

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/blazor/security/blazor-web-app-with-oidc.md

Sets the identity provider authority and client ID using specific Tenant ID and Client ID GUID values.

```csharp
oidcOptions.Authority = "https://login.microsoftonline.com/aaaabbbb-0000-cccc-1111-dddd2222eeee/v2.0";
oidcOptions.ClientId = "00001111-aaaa-2222-bbbb-3333cccc4444";
```

--------------------------------

### Email confirmation body example for GET /confirmEmail

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/security/authentication/identity-api-authorization.md

Default email confirmation body structure generated during registration containing the link with userId, code, and optional changedEmail parameters.

```http
 Please confirm your account by <a href='https://contoso.com/confirmEmail?userId={user ID}&code={generated code}&changedEmail={new email address}'>clicking here</a>.
```

--------------------------------

### Configure a single request delegate with app.Run in Startup

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/middleware/index.md

Sets up a minimal request delegate in Startup.Configure that handles all HTTP requests and terminates the pipeline.

```csharp
public class Startup
{
    public void Configure(IApplicationBuilder app)
    {
        app.Run(async context =>
        {
            await context.Response.WriteAsync("Hello, World!");
        });
    }
}
```

--------------------------------

### HostingAbstractionsHostExtensions.Start

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/host/generic-host.md

Launches the host synchronously without waiting for the host to complete before returning.

```APIDOC
## Start

### Description
Launches the host synchronously.

### Syntax
`public static void Start(this IHost host)`
```

--------------------------------

### Enable options validation at startup with ValidateOnStart

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/fundamentals/configuration/options.md

Configures options validation to run when the app starts during dependency injection setup. Use ValidateOnStart in Program.cs to validate options immediately rather than on first access.

```csharp
builder.Services.AddOptions<KeyOptions>()
    .Bind(builder.Configuration.GetSection(KeyOptions.Key))
    .ValidateDataAnnotations()
    .ValidateOnStart();
```

--------------------------------

### Read environment variables directly in .NET 11 WebAssemblyHostBuilder

Source: https://github.com/dotnet/aspnetcore.docs/blob/main/aspnetcore/breaking-changes/11/wasm-env-vars-in-configuration.md

Starting in ASP.NET Core 11, WebAssemblyHostBuilder.CreateDefault automatically calls AddEnvironmentVariables, making environment variables accessible from IConfiguration without manual setup.

```csharp
var builder = WebAssemblyHostBuilder.CreateDefault(args);

// Works without an explicit AddEnvironmentVariables call.
var endpoint = builder.Configuration["OTEL_EXPORTER_OTLP_ENDPOINT"];
```