Code

To run a GraphQL.js hello world script from the command line:

npm install graphql

Then run node hello.js with this code in hello.js:

var { graphql, buildSchema } = require('graphql');
 
var schema = buildSchema(`
  type Query {
    hello: String
  }
`);
 
var root = { hello: () => 'Hello world!' };
 
graphql(schema, '{ hello }', root).then((response) => {
  console.log(response);
});

To run a hello world server with apollo-server-express:

npm install apollo-server-express express

Then run node server.js with this code in server.js:

const express = require('express');
const { ApolloServer, gql } = require('apollo-server-express');
 
const typeDefs = gql`
  type Query {
    hello: String
  }
`;
 
const resolvers = {
  Query: {
    hello: () => 'Hello world!',
  },
};
 
const server = new ApolloServer({ typeDefs, resolvers });
 
const app = express();
server.applyMiddleware({ app });
 
app.listen({ port: 4000 }, () =>
  console.log('Now browse to http://localhost:4000' + server.graphqlPath)
);

Apollo Server also supports all Node.js HTTP server frameworks: Express, Connect, HAPI, Koa and NestJs.

To run an express-graphql hello world server:

npm install express express-graphql graphql

Then run node server.js with this code in server.js:

var express = require('express');
var { graphqlHTTP } = require('express-graphql');
var { buildSchema } = require('graphql');
 
var schema = buildSchema(`
  type Query {
    hello: String
  }
`);
 
var root = { hello: () => 'Hello world!' };
 
var app = express();
app.use('/graphql', graphqlHTTP({
  schema: schema,
  rootValue: root,
  graphiql: true,
}));
app.listen(4000, () => console.log('Now browse to localhost:4000/graphql'));

• Sensible defaults & includes everything you need with minimal setup.
• Built-in support for GraphQL subscriptions using WebSockets.
• Works with all GraphQL clients (Apollo, Relay...) and fits seamless in your GraphQL workflow.

To run a hello world server with graphql-yoga:

npm install graphql-yoga

Then run node server.js with this code in server.js:

import { GraphQLServer } from 'graphql-yoga'
// ... or using "require()"
// const { GraphQLServer } = require('graphql-yoga')
const typeDefs = `
  type Query {
    hello(name: String): String!
  }
`;
const resolvers = {
  Query: {
    hello: (_, { name }) => `Hello ${name || 'World'}`,
  },
};
const server = new GraphQLServer({ typeDefs, resolvers })
server.start(() => console.log('Server is running on localhost:4000'))

To run a hello world server with GraphQL Helix:

npm install graphql graphql-helix express

Then run node server.js with this code in server.js:

const express = require('express')
const {
  GraphQLObjectType,
  GraphQLSchema,
  GraphQLString
} = require('graphql');
const {
  getGraphQLParameters,
  processRequest,
  renderGraphiQL,
  shouldRenderGraphiQL
} = require('graphql-helix');
 
const schema = new GraphQLSchema({
  query: new GraphQLObjectType({
    name: 'Query',
    fields: {
      hello: {
        type: GraphQLString,
        resolve: () => 'Hello world!',
      },
    },
  }),
});
 
const app = express();
 
app.use(express.json());
 
app.use('/graphql', async (req, res) => {
  const request = {
    body: req.body,
    headers: req.headers,
    method: req.method,
    query: req.query,
  };
 
  if (shouldRenderGraphiQL(request)) {
    res.send(renderGraphiQL());
  } else {
    const { operationName, query, variables } = getGraphQLParameters(request);
 
    const result = await processRequest({
      operationName,
      query,
      variables,
      request,
      schema,
    });
 
    if (result.type === 'RESPONSE') {
      result.headers.forEach(({ name, value }) => res.setHeader(name, value));
      res.status(result.status);
      res.json(result.payload);
    } else {
    // graphql-helix also supports subscriptions and incremental delivery (i.e. @defer and @stream directives)
    // out of the box. See the repo for more complete examples that also implement those features.
    }
  }
});
 
app.listen(4000, () =>
  console.log('Now browse to http://localhost:4000/graphql');
)

This example uses Express, but GraphQL Helix is framework- and runtime-agnostic -- it can run in Node, Deno and the browser. GraphQL Helix provides you with a handful of utility functions to build your own HTTP server but leaves the ultimate implementation details up to you.

A powerful JavaScript GraphQL client, designed to work well with React, React Native, Angular 2, or just plain JavaScript.

Facebook's framework for building React applications that talk to a GraphQL backend.

A JavaScript library for application development using cloud services, which supports GraphQL backend and React components for working with GraphQL data.

urql is a GraphQL client that exposes a set of helpers for several frameworks. It's built to be highly customisable and versatile so you can take it from getting started with your first GraphQL project all the way to building complex apps and experimenting with GraphQL clients.

• Currently supports React, React Native, Preact, Svelte, and Vue, and is supported by GraphQL Code Generator.
• Logical yet simple default behaviour and document caching, and normalized caching via @urql/exchange-graphcache
• Fully customizable behaviour via "exchanges" (addon packages)

A simple and flexible JavaScript GraphQL client that works in all JavaScript environments (the browser, Node.js, and React Native) - basically a lightweight wrapper around fetch.

curl for GraphQL with autocomplete, subscriptions and GraphiQL. Also a dead-simple universal javascript GraphQL client.

A simple JavaScript GraphQL client that works in all JavaScript environments (the browser, Node.js, and React Native).

• 🥇 First-class hooks API
• ⚖️ Tiny bundle: only 7.6kB (2.8 gzipped)
• 📄 Full SSR support: see graphql-hooks-ssr
• 🔌 Plugin Caching: see graphql-hooks-memcache
• 🔥 No more render props hell
• ⏳ Handle loading and error states with ease

Quickstart#

npm install graphql-hooks

First you'll need to create a client and wrap your app with the provider:

import { GraphQLClient, ClientContext } from 'graphql-hooks'
 
const client = new GraphQLClient({
  url: '/graphql'
})
 
function App() {
  return (
    <ClientContext.Provider value={client}>
      {/* children */}
    </ClientContext.Provider>
  )
}

Now in your child components you can make use of useQuery:

import { useQuery } from 'graphql-hooks'
 
const HOMEPAGE_QUERY = `query HomePage($limit: Int) {
  users(limit: $limit) {
    id
    name
  }
}`
 
function MyComponent() {
  const { loading, error, data } = useQuery(HOMEPAGE_QUERY, {
    variables: {
      limit: 10
    }
  })
 
  if (loading) return 'Loading...'
  if (error) return 'Something Bad Happened'
 
  return (
    <ul>
      {data.users.map(({ id, name }) => (
        <li key={id}>{name}</li>
      ))}
    </ul>
  )
}

Tiny GraphQL client library using template strings.

An all purpose GraphQL client with view layer integrations for multiple frameworks in just 1.6kb.

A simple JavaScript GraphQL client，Let the *.gql file be used as a module through webpack loader.

builds a powerful, extensible and performant GraphQL API from a PostgreSQL schema in seconds; saving you weeks if not months of development time.

GraphQL code generator with flexible support for custom plugins and templates like Typescript (frontend and backend), React Hooks, resolvers signatures and more.

An interactive in-browser GraphQL IDE.

A set of utils for faster development of GraphQL tools (Schema and documents loading, Schema merging and more).

GraphQL Shield helps you create a permission layer for your application. Using an intuitive rule-API, you'll gain the power of the shield engine on every request and reduce the load time of every request with smart caching. This way you can make sure your application will remain quick, and no internal data will be exposed.

import { rule, shield, and, or, not } from 'graphql-shield'
 
// Rules
 
const isAuthenticated = rule({ cache: 'contextual' })(
  async (parent, args, ctx, info) => {
    return ctx.user !== null
  },
)
 
const isAdmin = rule({ cache: 'contextual' })(
  async (parent, args, ctx, info) => {
    return ctx.user.role === 'admin'
  },
)
 
const isEditor = rule({ cache: 'contextual' })(
  async (parent, args, ctx, info) => {
    return ctx.user.role === 'editor'
  },
)
 
// Permissions
 
const permissions = shield({
  Query: {
    frontPage: not(isAuthenticated),
    fruits: and(isAuthenticated, or(isAdmin, isEditor)),
    customers: and(isAuthenticated, isAdmin),
  },
  Mutation: {
    addFruitToBasket: isAuthenticated,
  },
  Fruit: isAuthenticated,
  Customer: isAdmin,
})
 
// Server
 
const server = new GraphQLServer({
  typeDefs,
  resolvers,
  middlewares: [permissions],
  context: (req) => ({
    ...req,
    user: getUser(req),
  }),
})

Compare schemas, validate documents, find breaking changes, find similar types, schema coverage, and more.

Coherent, zero-dependency, lazy, simple, GraphQL over WebSocket Protocol compliant server and client.

A command line tool for common GraphQL development workflows.

One configuration for all your GraphQL tools (supported by most tools, editors & IDEs).

GraphQL Middleware is a schema wrapper which allows you to manage additional functionality across multiple resolvers efficiently.

Features#

💡 Easy to use: An intuitive, yet familiar API that you will pick up in a second. 💪 Powerful: Allows complete control over your resolvers (Before, After). 🌈 Compatible: Works with any GraphQL Schema.

Example#

const { ApolloServer } = require('apollo-server')
const { makeExecutableSchema } = require('@graphql-tools/schema')
 
const typeDefs = `
type Query {
  hello(name: String): String
  bye(name: String): String
}
`
const resolvers = {
  Query: {
    hello: (root, args, context, info) => {
      console.log(`3. resolver: hello`)
      return `Hello ${args.name ? args.name : 'world'}!`
    },
    bye: (root, args, context, info) => {
      console.log(`3. resolver: bye`)
      return `Bye ${args.name ? args.name : 'world'}!`
    },
  },
}
 
const logInput = async (resolve, root, args, context, info) => {
  console.log(`1. logInput: ${JSON.stringify(args)}`)
  const result = await resolve(root, args, context, info)
  console.log(`5. logInput`)
  return result
}
 
const logResult = async (resolve, root, args, context, info) => {
  console.log(`2. logResult`)
  const result = await resolve(root, args, context, info)
  console.log(`4. logResult: ${JSON.stringify(result)}`)
  return result
}
 
const schema = makeExecutableSchema({ typeDefs, resolvers })
 
const schemaWithMiddleware = applyMiddleware(schema, logInput, logResult)
 
const server = new ApolloServer({
  schema: schemaWithMiddleware,
})
 
await server.listen({ port: 8008 })

A library of custom GraphQL scalar types for creating precise, type-safe GraphQL schemas.

GraphQL-ESLint integrates GraphQL AST in the ESLint core (as a parser).

GraphQL Mesh allows you to use GraphQL query language to access data in remote APIs that don't run GraphQL (and also ones that do run GraphQL). It can be used as a gateway to other services, or run as a local GraphQL schema that aggregates data from remote APIs.

Generate REST API from your GraphQL API.

An interface for building GraphQL language services for IDEs (diagnostics, autocomplete etc).

GraphQL Modules lets you separate your backend implementation to small, reusable, easy-to-implement and easy-to-test pieces.

Real-Time with GraphQL for any GraphQL schema or transport.

GiraphQL makes writing type-safe schemas simple, and works without a code generator, build process, or extensive manual type definitions.

import { ApolloServer } from "apollo-server"
import SchemaBuilder from "@giraphql/core"
 
const builder = new SchemaBuilder({})
 
builder.queryType({
  fields: t => ({
    hello: t.string({
      args: {
        name: t.arg.string({}),
      },
      resolve: (parent, { name }) => `hello, ${name || "World"}`,
    }),
  }),
})
 
new ApolloServer({
  schema: builder.toSchema({}),
}).listen(3000)

An implementation of GraphQL for Go / Golang.

Go generate based graphql server library.

An active implementation of GraphQL in Golang (was https://github.com/neelance/graphql-go).

A GraphQL implementation with easy schema building, live queries, and batching.

A Go/Golang library to help construct a graphql-go server supporting react-relay.

Develop spec compliant GraphQL servers in Go.

An elegant low-level HTTP client for GraphQL.

A GraphQL client implementation in Go.

A GraphQL Go client with Mutation, Query and Subscription support.

An instant GraphQL to SQL compiler. Use as a standalone service or a Go library. Formerly super-graph.

The following class is enough to create both a Relay-compatible GraphQL server and a hypermedia API supporting modern REST formats (JSON-LD, JSONAPI...):

<?php
 
namespace AppEntity;
 
use ApiPlatformCoreAnnotationApiResource;
use DoctrineORMMapping as ORM;
 
/**
 * Greet someone!
 *
 * @ApiResource
 * @ORMEntity
 */
class Greeting
{
    /**
     * @ORMId
     * @ORMColumn(type="guid")
     */
    public $id;
 
    /**
     * @var string Your nice message
     *
     * @ORMColumn
     */
    public $hello;
}

Other API Platform features include data validation, authentication, authorization, deprecations, cache and GraphiQL integration.

A PHP port of GraphQL reference implementation

A free, open-source WordPress plugin that provides an extendable GraphQL schema and API for any WordPress site

A GraphQL server for Laravel

To run a Siler hello world script:

type Query {
  hello: String
}

<?php
declare(strict_types=1);
require_once '/path/to/vendor/autoload.php';
 
use SilerDiactoros;
use SilerGraphql;
use SilerHttp;
 
$typeDefs = file_get_contents(__DIR__.'/schema.graphql');
$resolvers = [
    'Query' => [
        'hello' => 'world',
    ],
];
$schema = Graphqlschema($typeDefs, $resolvers);
 
echo "Server running at http://127.0.0.1:8080";
 
Httpserver(Graphqlpsr7($schema), function (Throwable $err) {
    var_dump($err);
    return Diactorosjson([
        'error'   => true,
        'message' => $err->getMessage(),
    ]);
})()->run();

It also provides functionality for the construction of a WebSocket Subscriptions Server based on how Apollo works.

A GraphQL server for Symfony

It is framework agnostic with bindings available for Symfony and Laravel. This code declares a "product" query and a "Product" Type:

class ProductController
{
    /**
     * @Query()
     */
    public function product(string $id): Product
    {
        // Some code that looks for a product and returns it.
    }
}
 
/**
 * @Type()
 */
class Product
{
    /**
     * @Field()
     */
    public function getName(): string
    {
        return $this->name;
    }
    // ...
}

Other GraphQLite features include validation, security, error handling, loading via data-loader pattern...

A PHP GraphQL Framework.

A library to help construct a graphql-php server supporting react-relay.

GraphQL by PoP follows the code-first approach to generate the schema (it can be customized for different clients/applications). Fields are dynamically "subscribed" to types, and may or may not be added to the schema depending on the context.

This is how a User type is satisfied:

class UserTypeResolver extends AbstractTypeResolver
{
  public function getTypeName(): string
  {
    return 'User';
  }
 
  public function getSchemaTypeDescription(): ?string
  {
    $translationAPI = TranslationAPIFacade::getInstance();
    return $translationAPI->__('Representation of a user', 'users');
  }
 
  public function getID(object $user)
  {
    return $user->ID;
  }
 
  public function getTypeDataLoaderClass(): string
  {
    return UserTypeDataLoader::class;
  }
}

Please notice how the TypeResolver does not indicate which are its fields. It also does not load the objects from the database, but instead delegates this task to a TypeDataLoader.

Adding fields to the type is done via a FieldResolver:

class UserFieldResolver extends AbstractDBDataFieldResolver
{
  public static function getClassesToAttachTo(): array
  {
    return [
      UserTypeResolver::class,
    ];
  }
 
  public static function getFieldNamesToResolve(): array
  {
    return [
      'username',
      'email',
      'url',
    ];
  }
 
  public function getSchemaFieldDescription(
    TypeResolverInterface $typeResolver,
    string $fieldName
  ): ?string {
    $translationAPI = TranslationAPIFacade::getInstance();
    $descriptions = [
      'username' => $translationAPI->__("User's username handle", "users"),
      'email' => $translationAPI->__("User's email", "users"),
      'url' => $translationAPI->__("URL of the user's profile in the website", "users"),
    ];
    return $descriptions[$fieldName];
  }
 
  public function getSchemaFieldType(
    TypeResolverInterface $typeResolver,
    string $fieldName
  ): ?string {
    $types = [
      'username' => SchemaDefinition::TYPE_STRING,
      'email' => SchemaDefinition::TYPE_EMAIL,
      'url' => SchemaDefinition::TYPE_URL,
    ];
    return $types[$fieldName];
  }
 
  public function resolveValue(
    TypeResolverInterface $typeResolver,
    object $user,
    string $fieldName,
    array $fieldArgs = []
  ) {
    switch ($fieldName) {
      case 'username':
        return $user->user_login;
 
      case 'email':
        return $user->user_email;
 
      case 'url':
        $userService = UserServiceFacade::getInstance();
        return $userService->getUserProfileURL($user->ID);
    }
 
    return null;
  }
}

The definition of a field for the GraphQL schema, and its resolution, is split into a multitude of functions from the FieldResolver:

• getSchemaFieldDescription
• getSchemaFieldType
• resolveValue
• getSchemaFieldArgs
• isSchemaFieldResponseNonNullable
• getImplementedInterfaceClasses
• resolveFieldTypeResolverClass
• resolveFieldMutationResolverClass

This code is more legible than if all functionality is satisfied through a single function, or through a configuration array, making it easier to implement and maintain the resolvers.

A GraphQL server for WordPress. Based on GraphQL by PoP

A GraphQL implementation for modern PHP

Use GraphQL to define your Domain Model for CQRS/ES and let serge generate code to handle GraphQL requests.

using System;
using System.Threading.Tasks;
using GraphQL;
using GraphQL.Types;
using GraphQL.SystemTextJson; // First add PackageReference to GraphQL.SystemTextJson
 
public class Program
{
  public static async Task Main(string[] args)
  {
    var schema = Schema.For(@"
      type Query {
        hello: String
      }
    ");
 
    var json = await schema.ExecuteAsync(_ =>
    {
      _.Query = "{ hello }";
      _.Root = new { Hello = "Hello World!" };
    });
 
    Console.WriteLine(json);
  }
}

Hot Chocolate takes the complexity away from building a fully-fledged GraphQL server and lets you focus on delivering the next big thing.

using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
 
WebHost
    .CreateDefaultBuilder(args)
    .ConfigureServices(services =>
        services
            .AddGraphQLServer()
            .AddQueryType<Query>())
    .Configure(builder =>
        builder
            .UseRouting()
            .UseEndpoints(e => e.MapGraphQL()))
    .Build()
    .Run();
 
public class Query
{
    public Hero GetHero() => new Hero();
}
 
public class Hero
{
    public string Name => "Luke Skywalker";
}

Convert GraphQL to IQueryable

.NET Core GraphQL library. Compiles to IQueryable to easily expose a schema from an existing data model (E.g. from an Entity Framework data model)

A set of packages for implementing high-performant GraphQL servers in .NET. Faithful implementation of official 2018 Specification. Features batched execution support (aka Data Loader); support for custom scalars; HTTP server based on ASP.NET Core; parsed query cache; modular API construction (equivalent of schema stiching); full introspection support; runtime metrics and quotas.

Strawberry Shake removes the complexity of state management and lets you interact with local and remote data through GraphQL.

You can use Strawberry Shake to:

• Generate a C# client from your GraphQL queries.
• Interact with local and remote data through GraphQL.
• Use reactive APIs to interact with your state.

client.GetHero
    .Watch(ExecutionStrategy.CacheFirst)
    .Subscribe(result => 
    {
        Console.WriteLine(result.Data.Name);
    })

A GraphQL Client for .NET.

Basic example GraphQL client for .NET.

GraphQL client which supports generating queries from C# classes

To run a Graphene hello world script:

pip install graphene

Then run python hello.py with this code in hello.py:

import graphene
 
class Query(graphene.ObjectType):
  hello = graphene.String(name=graphene.String(default_value="World"))
 
  def resolve_hello(self, info, name):
    return 'Hello ' + name
 
schema = graphene.Schema(query=Query)
result = schema.execute('{ hello }')
print(result.data['hello']) # "Hello World"

There are also nice bindings for Relay, Django, SQLAlchemy, and Google App Engine.

Ariadne can be installed with pip:

pip install ariadne

It ships with many GraphQL server implementations, enabling easy experimentation:

from ariadne import ObjectType, QueryType, gql, make_executable_schema
from ariadne.asgi import GraphQL
# Define types using Schema Definition Language (https://graphql.org/learn/schema/)
# Wrapping string in gql function provides validation and better error traceback
type_defs = gql("""
    type Query {
        hello: String!
    }
""")
# Bind resolver functions to Query's fields using QueryType
query_type = QueryType()
# Resolvers are simple python functions
@query_type.field("hello")
def resolve_hello(*_):
    return "Hello world!"
# Create executable GraphQL schema
schema = make_executable_schema(type_defs, query_type)
# Create an ASGI app using the schema, running in debug mode
app = GraphQL(schema, debug=True)

Above server can be ran with uvicorn:

pip install uvicorn
uvicorn example:app

Here's an example of a Strawberry hello world, first install the library:

pip install strawberry-graphql

Create an app.py file with this content:

import strawberry
 
@strawberry.type
class Query:
    @strawberry.field
    def hello(self, name: str = "World") -> str:
        return f"Hello {name}"
 
schema = strawberry.Schema(query=Query)

Then run strawberry server app and you will have a basic schema server running on http://localhost:8000/.

Strawberry also has views for ASGI, Flask and Django and provides utilities like dataloaders and tracing.

To run a tartiflette hello world script:

pip install tartiflette

Then run python hello.py with this code in hello.py:

import asyncio
from tartiflette import Engine, Resolver
@Resolver("Query.hello")
async def resolver_hello(parent, args, ctx, info):
    return "hello " + args["name"]
async def run():
    tftt_engine = Engine("""
    type Query {
        hello(name: String): String
    }
    """)
    result = await tftt_engine.execute(
        query='query { hello(name: "Chuck") }'
    )
    print(result)
    # {'data': {'hello': 'hello Chuck'}}
if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    loop.run_until_complete(run())

There is also a nice HTTP wrapper.

A GraphQL client in Python.

A simple Python GraphQL client. Supports generating code generation for types defined in a GraphQL schema.

Simple GraphQL client for Python 2.7+.

Code that executes a hello world GraphQL query with graphql-java:

import graphql.ExecutionResult;
import graphql.GraphQL;
import graphql.schema.GraphQLSchema;
import graphql.schema.StaticDataFetcher;
import graphql.schema.idl.RuntimeWiring;
import graphql.schema.idl.SchemaGenerator;
import graphql.schema.idl.SchemaParser;
import graphql.schema.idl.TypeDefinitionRegistry;
 
import static graphql.schema.idl.RuntimeWiring.newRuntimeWiring;
 
public class HelloWorld {
 
    public static void main(String[] args) {
        String schema = "type Query{hello: String} schema{query: Query}";
 
        SchemaParser schemaParser = new SchemaParser();
        TypeDefinitionRegistry typeDefinitionRegistry = schemaParser.parse(schema);
 
        RuntimeWiring runtimeWiring = new RuntimeWiring()
                .type("Query", builder -> builder.dataFetcher("hello", new StaticDataFetcher("world")))
                .build();
 
        SchemaGenerator schemaGenerator = new SchemaGenerator();
        GraphQLSchema graphQLSchema = schemaGenerator.makeExecutableSchema(typeDefinitionRegistry, runtimeWiring);
 
        GraphQL build = GraphQL.newGraphQL(graphQLSchema).build();
        ExecutionResult executionResult = build.execute("{hello}");
 
        System.out.println(executionResult.getData().toString());
        // Prints: {hello=world}
    }
}

See the graphql-java docs for more information on setup.

GraphQL Kotlin follows a code first approach for generating your GraphQL schemas. Given the similarities between Kotlin and GraphQL, such as the ability to define nullable/non-nullable types, a schema can be generated from Kotlin code without any separate schema specification. To create a reactive GraphQL web server add following dependency to your Gradle build file:

// build.gradle.kts
implementation("com.expediagroup", "graphql-kotlin-spring-server", latestVersion)

We also need to provide a list of supported packages that can be scanned for exposing your schema objects through reflections. Add following configuration to your application.yml file:

graphql:
  packages:
    - "com.your.package"

With the above configuration we can now create our schema. In order to expose your queries, mutations and/or subscriptions in the GraphQL schema you simply need to implement corresponding marker interface and they will be automatically picked up by graphql-kotlin-spring-server auto-configuration library.

@Component
class HelloWorldQuery : Query {
  fun helloWorld() = "Hello World!!!"
}

This will result in a reactive GraphQL web application with following schema:

type Query {
  helloWorld: String!
}

See graphql-kotlin docs for additial details.

Here's an example on how to create a simple schema based on a kotlin data class plus a property resolver that gets applied onto your class.

data class Article(val id: Int, val text: String)
 
fun main() {
    val schema = KGraphQL.schema {
        query("article") {
            resolver { id: Int?, text: String ->
                Article(id ?: -1, text)
            }
        }
        type<Article> {
            property<String>("fullText") {
                resolver { article: Article ->
                    "${article.id}: ${article.text}"
                }
            }
        }
    }
 
    schema.execute("""
        {
            article(id: 5, text: "Hello World") {
                id
                fullText
            }
        }
    """).let(::println)
}

KGraphQL is using coroutines behind the scenes to provide great asynchronous performance.

See KGraphQL docs for more in depth usage.

Ktor Plugin#

KGraphQL has a Ktor plugin which gives you a fully functional GraphQL server with a single install function call. Example below shows how to set up a GraphQL server within Ktor and it will give you a GraphQL Playground out of the box by entering localhost:8080/graphql.

fun Application.module() {
  install(GraphQL) {
    playground = true 
    schema {
      query("hello") {
        resolver { -> "World!" }
      }
    }
  }
}

You can follow the Ktor tutorial to set up a KGraphQL server with ktor from scratch up.

A strongly-typed, caching GraphQL client for Android, written in Java.

GraphQL Kotlin provides a set of lightweight type-safe GraphQL HTTP clients. The library provides Ktor HTTP client and Spring WebClient based reference implementations as well as allows for custom implementations using other engines. Type-safe data models are generated at build time by the GraphQL Kotlin Gradle and Maven plugins.

To generate Ktor based GraphQL client add following to your Gradle build file:

// build.gradle.kts
import com.expediagroup.graphql.plugin.generator.GraphQLClientType
import com.expediagroup.graphql.plugin.gradle.graphql
 
plugins {
    id("com.expediagroup.graphql") version $latestGraphQLKotlinVersion
}
 
dependencies {
  implementation("com.expediagroup:graphql-kotlin-ktor-client:$latestGraphQLKotlinVersion")
}
 
graphql {
    client {
        // target GraphQL endpoint
        endpoint = "http://localhost:8080/graphql"
        // package for generated client code
        packageName = "com.example.generated"
        clientType = GraphQLClientType.KTOR
    }
}

By default, GraphQL Kotlin plugin will look for query files under src/main/resources. Given helloWorld: String! query we can add following HelloWorldQuery.graphql sample query to our repo:

query HelloWorldQuery {
  helloWorld
}

Plugin will generate following client code:

package com.example.generated
 
import com.expediagroup.graphql.client.GraphQLKtorClient
import com.expediagroup.graphql.types.GraphQLResponse
import kotlin.String
 
const val HELLO_WORLD_QUERY: String = "query HelloWorldQuery {\n    helloWorld\n}"
 
class HelloWorldQuery(
  private val graphQLClient: GraphQLKtorClient<*>
) {
  suspend fun execute(requestBuilder: HttpRequestBuilder.() -> Unit = {}): GraphQLResponse<HelloWorldQuery.Result> =
      graphQLClient.execute(HELLO_WORLD_QUERY, "HelloWorldQuery", null, requestBuilder)
 
  data class Result(
    val helloWorld: String
  )
}

We can then execute the client

package com.example.client
 
import com.expediagroup.graphql.client.GraphQLKtorClient
import com.expediagroup.graphql.generated.HelloWorldQuery
import kotlinx.coroutines.runBlocking
import java.net.URL
 
fun main() {
    val client = GraphQLKtorClient(url = URL("http://localhost:8080/graphql"))
    val helloWorldQuery = HelloWorldQuery(client)
    runBlocking {
        val result = helloWorldQuery.execute()
        println("hello world query result: ${result.data?.helloWorld}")
    }
    client.close()
}

See graphql-kotlin docs for additial details.

A GraphQL JVM Client designed for constructing queries from standard model definitions. By American Express.

• GraphQL Java client: it generates the Java classes that call the GraphQL endpoint, and the POJO that will contain the data returned by the server. The GraphQL endpoint can then be queried by using a simple call to a Java method (see sample below)
• GraphQL Java server: it is based on graphql-java (listed here above). It generates all the boilerplate code. You'll only have to implement what's specific to your server, which are the joins between the GraphQL types. GraphQL Java Generator is available as a Maven Plugin. A Gradle plugin is coming soon. Please note that GraphQL Java Generator is an accelerator: the generated code doesn’t depend on any library specific to GraphQL Java Generator. So, it helps you to start building application based on graphql-java. Once the code is generated, you can decide to manually edit it as any standard java application, and get rid of GraphQL Java Generator. Of course you can, and should, according to us :), continue using GraphQL Java Generator when your projet evolves.

To run a hello world script with graphql-ruby:

gem install graphql

Then run ruby hello.rb with this code in hello.rb:

require 'graphql'
 
class QueryType < GraphQL::Schema::Object
  graphql_name 'Query'
  field :hello do
    type types.String
    resolve -> (obj, args, ctx) { 'Hello world!' }
  end
end
 
class Schema < GraphQL::Schema
  query QueryType
end
 
puts Schema.execute('{ hello }').to_json

There are also nice bindings for Relay and Rails.

require 'agoo'
 
class Query
  def hello
    'hello'
  end
end
 
class Schema
  attr_reader :query
 
  def initialize
    @query = Query.new()
  end
end
 
Agoo::Server.init(6464, 'root', thread_count: 1, graphql: '/graphql')
Agoo::Server.start()
Agoo::GraphQL.schema(Schema.new) {
  Agoo::GraphQL.load(%^type Query { hello: String }^)
}
sleep
 
# To run this GraphQL example type the following then go to a browser and enter
# a URL of localhost:6464/graphql?query={hello}
#
# ruby hello.rb

GraphQL server library for Rust

 use async_graphql::*;
 struct Query;
 #[Object]
 impl Query {
    /// Returns the sum of a and b
    async fn add(&self, a: i32, b: i32) -> i32 {
        a + b
    }
 }

A client library for rust that generates queries from types you provide, verifying that the types match the shape of your schema.

It provides a generator to bootstrap types from existing GraphQL queries.

Usage example:

#[derive(cynic::QueryFragment, Debug)]
#[cynic(
    schema_path = "../schemas/starwars.schema.graphql",
    query_module = "query_dsl",
    graphql_type = "Root",
    argument_struct = "FilmArguments"
)]
struct FilmDirectorQuery {
    #[arguments(id = &args.id)]
    film: Option<Film>,
}
 
#[derive(cynic::QueryFragment, Debug)]
#[cynic(
    schema_path = "../schemas/starwars.schema.graphql",
    query_module = "query_dsl",
    graphql_type = "Film"
)]
struct Film {
    title: Option<String>,
    director: Option<String>,
}
 
#[derive(cynic::FragmentArguments)]
struct FilmArguments {
    id: Option<cynic::Id>,
}
 
fn main() {
    use cynic::{QueryBuilder, http::ReqwestBlockingExt};
 
    let query = FilmDirectorQuery::build(&FilmArguments {
        id: Some("ZmlsbXM6MQ==".into()),
    })
 
    reqwest::blocking::Client::new()
        .post("https://swapi-graphql.netlify.com/.netlify/functions/index")
        .run_graphql(query)
        .unwrap()
}
 
mod query_dsl {
    cynic::query_dsl!("../schemas/starwars.schema.graphql");
}

Usage example

use gql_client::Client;
 
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
  let endpoint = "https://graphqlzero.almansi.me/api";
  let query = r#"
    query AllPostsQuery {
      posts {
        data {
          id
        }
      }
    }
  "#;
 
  let client = Client::new(endpoint);
  let data: AllPosts = client.query::<AllPosts>(query).await.unwrap();
 
  println!("{:?}" data);
 
  Ok(())
}