GraphQL for .NET

This is an implementation of Facebook's GraphQL in .NET.

Now the specification is being developed by the GraphQL Foundation.

This project uses a lexer/parser originally written by Marek Magdziak and released with a MIT license. Thank you Marek!

Documentation

http://graphql-dotnet.github.io

This site is in sync with master branch.

Installation

You can install the latest stable version via NuGet.

> dotnet add package GraphQL

For serialized results, you'll need an IDocumentWriter implementation. We support several serializers (or you can bring your own):

Package	Downloads	Nuget Latest
GraphQL.SystemTextJson
GraphQL.NewtonsoftJson

> dotnet add package GraphQL.SystemTextJson
> dotnet add package GraphQL.NewtonsoftJson

Note: You can use GraphQL.NewtonsoftJson with .NET Core 3+, just be aware it lacks async writing capabilities so writing to an ASP.NET Core 3.0 HttpResponse.Body will require you to set AllowSynchronousIO to true as per this announcement; which isn't recommended.

You can get all preview versions from GitHub Packages. Note that GitHub requires authentication to consume the feed. See here.

Examples

https://github.com/graphql-dotnet/examples

You can also try an example of GraphQL demo server inside this repo - GraphQL.Harness. It supports the popular IDEs for managing GraphQL requests and exploring GraphQL schema:

• Altair
• Firecamp
• GraphiQL
• GraphQL Playground
• Voyager

Training

• API Development in .NET with GraphQL - Glenn Block demonstrates how to use the GraphQL .NET framework to build a fully functional GraphQL endpoint.
• Building GraphQL APIs with ASP.NET Core by Roland Guijt

Upgrade Guides

You can see the changes in public APIs using fuget.org.

• 2.4.0 to 3.0
• 0.17.x to 2.x
• 0.11.0
• 0.8.0

Basic Usage

Define your schema with a top level query object then execute that query.

Fully-featured examples can be found here.

Hello World

var schema = Schema.For(@"
  type Query {
    hello: String
  }
");

var root = new { Hello = "Hello World!" };
var json = await schema.ExecuteAsync(_ =>
{
  _.Query = "{ hello }";
  _.Root = root;
});

Console.WriteLine(json);

Schema First Approach

This example uses the GraphQL schema language. See the documentation for more examples and information.

public class Droid
{
  public string Id { get; set; }
  public string Name { get; set; }
}

public class Query
{
  [GraphQLMetadata("droid")]
  public Droid GetDroid()
  {
    return new Droid { Id = "123", Name = "R2-D2" };
  }
}

var schema = Schema.For(@"
  type Droid {
    id: ID
    name: String
  }

  type Query {
    droid: Droid
  }
", _ => {
    _.Types.Include<Query>();
});

var json = await schema.ExecuteAsync(_ =>
{
  _.Query = "{ droid { id name } }";
});

Parameters

public class Droid
{
  public string Id { get; set; }
  public string Name { get; set; }
}

public class Query
{
  private List<Droid> _droids = new List<Droid>
  {
    new Droid { Id = "123", Name = "R2-D2" }
  };

  [GraphQLMetadata("droid")]
  public Droid GetDroid(string id)
  {
    return _droids.FirstOrDefault(x => x.Id == id);
  }
}

var schema = Schema.For(@"
  type Droid {
    id: ID
    name: String
  }

  type Query {
    droid(id: ID): Droid
  }
", _ => {
    _.Types.Include<Query>();
});

var json = await schema.ExecuteAsync(_ =>
{
  _.Query = $"{{ droid(id: \"123\") {{ id name }} }}";
});

Roadmap

Grammar / AST

• Grammar and AST for the GraphQL language should be compatible with the June 2018 specification.

Operation Execution

• Scalars
• Objects
• Lists of objects/interfaces
• Interfaces
• Unions
• Arguments
• Variables
• Fragments
• Directives
  • Include
  • Skip
  • Custom
• Enumerations
• Input Objects
• Mutations
• Subscriptions
• Async execution

Validation

• Arguments of correct type
• Default values of correct type
• Fields on correct type
• Fragments on composite types
• Known argument names
• Known directives
• Known fragment names
• Known type names
• Lone anonymous operations
• No fragment cycles
• No undefined variables
• No unused fragments
• No unused variables
• Overlapping fields can be merged
• Possible fragment spreads
• Provide non-null arguments
• Scalar leafs
• Unique argument names
• Unique directives per location
• Unique fragment names
• Unique input field names
• Unique operation names
• Unique variable names
• Variables are input types
• Variables in allowed position
• Single root field

Schema Introspection

• __typename
• __type
  • name
  • kind
  • description
  • fields
  • interfaces
  • possibleTypes
  • enumValues
  • inputFields
  • ofType
• __schema
  • types
  • queryType
  • mutationType
  • subscriptionType
  • directives

Publishing NuGet packages

The package publishing process is automated with GitHub Actions.

After your PR is merged into master or develop, preview packages are published to GitHub Packages.

Stable versions of packages are published to NuGet when a release is created.

Contributors

This project exists thanks to all the people who contribute.

Backers

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Sponsors

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