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Building Your First App

This document will help walk you through creating a new Web API project, installing the GraphQL ASP.NET library and writing your first controller.

Create a New Web API Project​

💻 Setup a new ASP.NET Core Web API project:

web api project

Add the Package From Nuget​

💻 Add the GraphQL.AspNet nuget package:

# Using the dotnet CLI
> dotnet add package GraphQL.AspNet

Create a Controller​

💻 Create your first Graph Controller:

BakeryController.cs
using GraphQL.AspNet.Attributes;
using GraphQL.AspNet.Controllers;

public class BakeryController : GraphController
{
    [QueryRoot("donut")]
    public Donut RetrieveDonut()
    {
        return new Donut()
        {
            Id = 3,
            Name = "Snowy Dream",
            Flavor = "Vanilla"
        };
    }
}

public class Donut
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Flavor { get; set; }
}

Configure Startup​

💻 Register GraphQL with your services collection and your application pipeline:

Program.cs
using GraphQL.AspNet.Configuration;

var builder = WebApplication.CreateBuilder(args);

// Add graphql services to the DI container.
builder.Services.AddGraphQL();

var app = builder.Build();

// Configure the HTTP request pipeline.
app.UseGraphQL();
app.Run();

The configuration steps may vary slightly when using a Startup.cs file; typical for .NET 5 or earlier

Execute a Query​

💻 Start the application and using your favorite tool, execute a query:

Sample Query
query {
    donut {
        id
        name
        flavor
    }
}

Results:​

query results

The port number on your app may be different than that shown in the image