Skip to content

Prerequisites

This documentation assumes your familiarity with GraphQL concepts. If it is not the case - first learn about GraphQL on the official website.

Installation

Using composer, run:

composer require webonyx/graphql-php

Upgrading

We try to keep library releases backwards compatible when possible. For breaking changes we provide upgrade instructions.

Install Tools (optional)

While it is possible to communicate with GraphQL API using regular HTTP tools it is way more convenient for humans to use GraphiQL - an in-browser IDE for exploring GraphQL APIs.

It provides syntax-highlighting, auto-completion and auto-generated documentation for GraphQL API.

The easiest way to use it is to install one of the existing Google Chrome extensions:

Alternatively, you can follow instructions on the GraphiQL page and install it locally.

Hello World

Let's create a type system that will be capable to process the following simple query:

query {
  echo(message: "Hello World")
}

We need an object type with the field echo:

<?php
use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\Type;

$queryType = new ObjectType([
    'name' => 'Query',
    'fields' => [
        'echo' => [
            'type' => Type::string(),
            'args' => [
                'message' => Type::nonNull(Type::string()),
            ],
            'resolve' => function ($rootValue, $args) {
                return $rootValue['prefix'] . $args['message'];
            }
        ],
    ],
]);

(Note: type definition can be expressed in different styles)

The interesting piece here is the resolve option of the field definition. It is responsible for returning a value of our field. Values of scalar fields will be directly included in the response while values of composite fields (objects, interfaces, unions) will be passed down to nested field resolvers (not in this example though).

Now when our type is ready, let's create a GraphQL endpoint file for it graphql.php:

<?php
use GraphQL\GraphQL;
use GraphQL\Type\Schema;

$schema = new Schema([
    'query' => $queryType
]);

$rawInput = file_get_contents('php://input');
$input = json_decode($rawInput, true);
$query = $input['query'];
$variableValues = isset($input['variables']) ? $input['variables'] : null;

try {
    $rootValue = ['prefix' => 'You said: '];
    $result = GraphQL::executeQuery($schema, $query, $rootValue, null, $variableValues);
    $output = $result->toArray();
} catch (\Exception $e) {
    $output = [
        'errors' => [
            [
                'message' => $e->getMessage()
            ]
        ]
    ];
}
header('Content-Type: application/json');
echo json_encode($output);

Our example is finished. Try it by running:

php -S localhost:8080 graphql.php
curl http://localhost:8080 -d '{"query": "query { echo(message: \"Hello World\") }" }'

Check out the full source code of this example which also includes simple mutation.

Check out the blog example for something which is closer to real-world apps or read about the details of schema definition.

Next Steps

Obviously hello world only scratches the surface of what is possible.

To learn by example, check out the blog example which is quite close to real-world GraphQL hierarchies.

For a deeper understanding of GraphQL in general, check out concepts.

To delve right into the implementation, see schema definition.