State Providers

To retrieve data exposed by the API, API Platform uses classes called state providers.

With the Symfony variant, a state provider using Doctrine ORM is ready to retrieve data from a database and a state provider using Doctrine MongoDB ODM to retrieve data from a document database.

With the Laravel variant, a state provider using Eloquent ORM to retrieve data from a relational database and a state provider.

The ORM providers are enabled by default, based on your framework variant (Eloquent or Doctrine will be set up).

These state providers natively support paged collections and filters. They can be used as-is and are perfectly suited to common uses.

However, you sometimes want to retrieve data from other sources such as another persistence layer or a webservice. Custom state providers can be used to do so. A project can include as many state providers as needed. The first able to retrieve data for a given resource will be used.

To do so you need to implement the ApiPlatform\State\ProviderInterface.

In the following examples we will create custom state providers for Symfony entities and Laravel models:

For Symfony we will create an entity class called App\Entity\BlogPost.
For Laravel, we will create a model class called App\Models\BlogPost.

Note, that if your entity is not Doctrine-related or Eloquent-related, you need to flag the identifier property by using #[ApiProperty(identifier: true) for things to work properly (see also Entity Identifier Case).

# Creating a Custom State Provider

# Custom State Provider with Symfony

If the Symfony MakerBundle is installed in your project, you can use the following command to generate a custom state provider easily:

bin/console make:state-provider

Let’s start with a State Provider for the URI: /blog_posts/{id}.

First, your BlogPostProvider has to implement the ProviderInterface:

<?php
// api/src/State/BlogPostProvider.php

namespace App\State;

use App\Entity\BlogPost;
use ApiPlatform\Metadata\Operation;
use ApiPlatform\State\ProviderInterface;

/**
 * @implements ProviderInterface<BlogPost|null>
 */
final class BlogPostProvider implements ProviderInterface
{
    private array $data;

    public function __construct() {
        $this->data = [
            'ab' => new BlogPost('ab'),
            'cd' => new BlogPost('cd'),
        ];
    }

    public function provide(Operation $operation, array $uriVariables = [], array $context = []): BlogPost|null
    {
        return $this->data[$uriVariables['id']] ?? null;
    }
}

For the example, we store the list of our blog posts in an associative array $data.

As this operation expects a BlogPost, the provide methods return the instance of the BlogPost corresponding to the ID passed in the URL. If the ID doesn’t exist in the associative array, provide() returns null. API Platform will automatically generate a 404 response if the provider returns null.

The $uriVariables parameter contains an array with the values of the URI variables.

To use this provider we need to configure the provider on the operation:

<?php
// api/src/Entity/BlogPost.php

namespace App\Entity;

use ApiPlatform\Metadata\Get;
use App\State\BlogPostProvider;

#[Get(provider: BlogPostProvider::class)]
class BlogPost {}

Now let’s say that we also want to handle the /blog_posts URI which returns a collection. We can change the Provider into supporting a wider range of operations. Then we can provide a collection of blog posts when the operation is a CollectionOperationInterface:

<?php
// api/src/State/BlogPostProvider.php

namespace App\State;

use App\Entity\BlogPost;
use ApiPlatform\Metadata\Operation;
use ApiPlatform\State\ProviderInterface;
use ApiPlatform\Metadata\CollectionOperationInterface;

/**
 * @implements ProviderInterface<BlogPost[]|BlogPost|null>
 */
final class BlogPostProvider implements ProviderInterface
{
    // …

    public function provide(Operation $operation, array $uriVariables = [], array $context = []): iterable|BlogPost|null
    {
        if ($operation instanceof CollectionOperationInterface) {
            return $this->data;
        }

        return $this->data[$uriVariables['id']] ?? null;
    }
}

We then need to configure this same provider on the BlogPost GetCollection operation, or for every operation via the ApiResource attribute:

<?php
// api/src/Entity/BlogPost.php

namespace App\Entity;

use ApiPlatform\Metadata\ApiResource;
use App\State\BlogPostProvider;

#[ApiResource(provider: BlogPostProvider::class)]
class BlogPost {}

# Custom State Provider with Laravel

Using Laravel Artisan Console, you can generate a custom state provider easily with the following command:

php artisan make:state-provider

Let’s start with a State Provider for the URI: /blog_posts/{id}.

First, your BlogPostProvider has to implement the ProviderInterface:

<?php
// api/src/State/BlogPostProvider.php

namespace App\State;

use App\Models\BlogPost;
use ApiPlatform\Metadata\Operation;
use ApiPlatform\State\ProviderInterface;

/**
 * @implements ProviderInterface<BlogPost|null>
 */
final class BlogPostProvider implements ProviderInterface
{
    private array $data;

    public function __construct() {
        $this->data = [
            'ab' => new BlogPost('ab'),
            'cd' => new BlogPost('cd'),
        ];
    }

    public function provide(Operation $operation, array $uriVariables = [], array $context = []): BlogPost|null
    {
        return $this->data[$uriVariables['id']] ?? null;
    }
}

For the example, we store the list of our blog posts in an associative array $data.

The $uriVariables parameter contains an array with the values of the URI variables.

To use this provider we need to configure the provider on the operation:

<?php
// api/src/Models/BlogPost.php

namespace App\Models;

use ApiPlatform\Metadata\Get;
use App\State\BlogPostProvider;

#[Get(provider: BlogPostProvider::class)]
class BlogPost {}

<?php
// api/src/State/BlogPostProvider.php

namespace App\State;

use App\Models\BlogPost;
use ApiPlatform\Metadata\Operation;
use ApiPlatform\State\ProviderInterface;
use ApiPlatform\Metadata\CollectionOperationInterface;

/**
 * @implements ProviderInterface<BlogPost[]|BlogPost|null>
 */
final class BlogPostProvider implements ProviderInterface
{
    // …

    public function provide(Operation $operation, array $uriVariables = [], array $context = []): iterable|BlogPost|null
    {
        if ($operation instanceof CollectionOperationInterface) {
            return $this->data;
        }

        return $this->data[$uriVariables['id']] ?? null;
    }
}

We then need to configure this same provider on the BlogPost GetCollection operation, or for every operation via the ApiResource attribute:

<?php
// api/src/Models/BlogPost.php

namespace App\Models;

use ApiPlatform\Metadata\ApiResource;
use App\State\BlogPostProvider;

#[ApiResource(provider: BlogPostProvider::class)]
class BlogPost {}

# Hooking into the Built-In State Provider

If you want to execute custom business logic before or after retrieving data, this can be achieved by decorating the built-in state providers or using composition.

The next examples (one for Symfony and one for Laravel) uses a DTO to change the presentation for data originally retrieved by the default state provider.

# Symfony State Provider mechanism

<?php
// api/src/State/BlogPostProvider.php

namespace App\State;

use App\Dto\AnotherRepresentation;
use App\Entity\Book;
use ApiPlatform\Metadata\Operation;
use ApiPlatform\State\ProviderInterface;
use Symfony\Component\DependencyInjection\Attribute\Autowire;

/**
 * @implements ProviderInterface<AnotherRepresentation>
 */
final class BookRepresentationProvider implements ProviderInterface
{
    public function __construct(
        #[Autowire(service: 'api_platform.doctrine.orm.state.item_provider')]
        private ProviderInterface $itemProvider,
    )
    {
    }

    public function provide(Operation $operation, array $uriVariables = [], array $context = []): AnotherRepresentation
    {
        $book = $this->itemProvider->provide($operation, $uriVariables, $context);

        return new AnotherRepresentation(
            // Add DTO constructor params here.
            // $book->getTitle(),
        );
    }
}

And configure that you want to use this provider on the Book resource:

<?php
// api/src/Entity/Book.php

namespace App\Entity;

use ApiPlatform\Metadata\Get;
use App\Dto\AnotherRepresentation;
use App\State\BookRepresentationProvider;

#[Get(output: AnotherRepresentation::class, provider: BookRepresentationProvider::class)]
class Book {}

# Laravel State Provider mechanism

Declare a class that implements our ProviderInterface

<?php
// api/app/State/BlogPostProvider.php

namespace App\State;

use App\Dto\AnotherRepresentation;
use App\Models\Book;
use ApiPlatform\Metadata\Operation;
use ApiPlatform\State\ProviderInterface;

/**
 * @implements ProviderInterface<AnotherRepresentation>
 */
final class BookRepresentationProvider implements ProviderInterface
{
    public function __construct(
        private ProviderInterface $itemProvider,
    )
    {
    }

    public function provide(Operation $operation, array $uriVariables = [], array $context = []): AnotherRepresentation
    {
        $book = $this->itemProvider->provide($operation, $uriVariables, $context);

        return new AnotherRepresentation(
            // Add DTO constructor params here.
            // $book->getTitle(),
        );
    }
}

And we bind the ItemProvider in our Service Provider

<?php
// app/Providers/AppServiceProvider.php

namespace App\Providers;

use App\State\BookRepresentationProvider;
use ApiPlatform\Laravel\Eloquent\State\ItemProvider;
use Illuminate\Support\ServiceProvider;
use Illuminate\Contracts\Foundation\Application;
class AppServiceProvider extends ServiceProvider
{
    /**
     * Register any application services.
     */
    public function register(): void
    {
        $this->app->singleton(BookRepresentationProvider::class, function (Application $app) {
            return new BookRepresentationProvider(
                $app->make(ItemProvider::class),
            );
        });
    }

    //...
}

Finally, configure that you want to use this provider on the Book resource:

<?php
// api/app/Models/Book.php

namespace App\Models;

use ApiPlatform\Metadata\Get;
use App\Dto\AnotherRepresentation;
use App\State\BookRepresentationProvider;

#[Get(output: AnotherRepresentation::class, provider: BookRepresentationProvider::class)]
class Book {}

# Customizing the Doctrine Query via `repositoryMethod` (Symfony only)

When using the built-in Doctrine ORM or MongoDB ODM state providers, you can instruct them to start from a custom query builder produced by your entity repository instead of the default createQueryBuilder('o') / createAggregationBuilder() call. This keeps all the standard provider behavior (pagination, filters, link handling, identifier WHERE clauses) intact while giving you full control over the base query.

Set repositoryMethod on the stateOptions of the operation:

<?php
// api/src/Entity/Product.php

namespace App\Entity;

use ApiPlatform\Doctrine\Orm\State\Options;
use ApiPlatform\Metadata\ApiResource;
use ApiPlatform\Metadata\Get;
use ApiPlatform\Metadata\GetCollection;
use App\Repository\ProductRepository;
use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity(repositoryClass: ProductRepository::class)]
#[ApiResource]
#[GetCollection(stateOptions: new Options(repositoryMethod: 'findAvailable'))]
#[Get(stateOptions: new Options(repositoryMethod: 'findAvailable'))]
class Product
{
    #[ORM\Id, ORM\GeneratedValue, ORM\Column]
    private ?int $id = null;

    #[ORM\Column]
    public bool $available = true;

    // ...
}

The repository method must be public and return a Doctrine\ORM\QueryBuilder for ORM (or a Doctrine\ODM\MongoDB\Aggregation\Builder for MongoDB ODM):

<?php
// api/src/Repository/ProductRepository.php

namespace App\Repository;

use App\Entity\Product;
use Doctrine\ORM\EntityRepository;
use Doctrine\ORM\QueryBuilder;

/**
 * @extends EntityRepository<Product>
 */
class ProductRepository extends EntityRepository
{
    public function findAvailable(): QueryBuilder
    {
        return $this->createQueryBuilder('o')
            ->andWhere('o.available = :available')
            ->setParameter('available', true);
    }
}

The providers apply identifier resolution (for item operations), pagination, and filters on top of the returned builder. A custom root alias is supported — the link handler reads the builder’s root alias automatically.

If the method does not exist on the repository, a RuntimeException is thrown: The repository method "ProductRepository::findAvailable" does not exist.

If the method returns a value that is not the expected builder type, a RuntimeException is thrown: The repository method "findAvailable" must return a QueryBuilder instance.

Because the filter applies at the item level too, a Get operation using a
repositoryMethod that filters rows will return a 404 response for any item excluded by that filter.

# GraphQL

repositoryMethod works identically for GraphQL queries. Use it on the ApiResource or on specific GraphQL operations:

<?php
// api/src/Entity/Product.php

namespace App\Entity;

use ApiPlatform\Doctrine\Orm\State\Options;
use ApiPlatform\Metadata\ApiResource;
use ApiPlatform\Metadata\GraphQl\Query;
use ApiPlatform\Metadata\GraphQl\QueryCollection;
use App\Repository\ProductRepository;
use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity(repositoryClass: ProductRepository::class)]
#[ApiResource(
    stateOptions: new Options(repositoryMethod: 'findAvailable'),
    graphQlOperations: [
        new Query(),
        new QueryCollection(),
    ]
)]
class Product
{
    // ...
}

# Computed Fields

A common use case is adding a computed scalar to each row using addSelect. Doctrine then returns mixed rows shaped [0 => $entity, 'fieldAlias' => $scalar] instead of plain entities. To map the scalar back onto the entity, combine repositoryMethod with a processor on the operation.

A processor only runs on a read operation when write: true is set on that operation. Without this flag the processor stage is skipped and the raw array rows reach normalization, which produces errors such as “Cannot return null for non-nullable field”. Set write: true explicitly to enable the processor.

REST example:

<?php
// api/src/Repository/CartRepository.php

namespace App\Repository;

use App\Entity\Cart;
use Doctrine\ORM\EntityRepository;
use Doctrine\ORM\QueryBuilder;

/**
 * @extends EntityRepository<Cart>
 */
class CartRepository extends EntityRepository
{
    public function getCartsWithTotalQuantity(): QueryBuilder
    {
        return $this->createQueryBuilder('o')
            ->leftJoin('o.items', 'items')
            ->addSelect('COALESCE(SUM(items.quantity), 0) AS totalQuantity')
            ->addGroupBy('o.id');
    }
}

<?php
// api/src/Entity/Cart.php

namespace App\Entity;

use ApiPlatform\Doctrine\Orm\State\Options;
use ApiPlatform\Metadata\GetCollection;
use ApiPlatform\Metadata\Operation;
use App\Repository\CartRepository;
use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity(repositoryClass: CartRepository::class)]
#[GetCollection(
    stateOptions: new Options(repositoryMethod: 'getCartsWithTotalQuantity'),
    processor: [self::class, 'process'],
    write: true,
)]
class Cart
{
    public ?int $totalQuantity = null;

    // ...

    public static function process(mixed $data, Operation $operation, array $uriVariables = [], array $context = []): mixed
    {
        foreach ($data as &$row) {
            $cart = $row[0];
            $cart->totalQuantity = $row['totalQuantity'] ?? 0;
            $row = $cart;
        }

        return $data;
    }
}

GraphQL example:

The same process method works for GraphQL. Declare it on the QueryCollection operation alongside write: true:

<?php
// api/src/Entity/Cart.php

namespace App\Entity;

use ApiPlatform\Doctrine\Orm\State\Options;
use ApiPlatform\Metadata\ApiResource;
use ApiPlatform\Metadata\GetCollection;
use ApiPlatform\Metadata\GraphQl\Query;
use ApiPlatform\Metadata\GraphQl\QueryCollection;
use ApiPlatform\Metadata\Operation;
use App\Repository\CartRepository;
use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity(repositoryClass: CartRepository::class)]
#[ApiResource(
    stateOptions: new Options(repositoryMethod: 'getCartsWithTotalQuantity'),
    graphQlOperations: [
        new Query(),
        new QueryCollection(
            processor: [self::class, 'process'],
            write: true,
        ),
    ],
)]
#[GetCollection(
    processor: [self::class, 'process'],
    write: true,
)]
class Cart
{
    public ?int $totalQuantity = null;

    // ...

    public static function process(mixed $data, Operation $operation, array $uriVariables = [], array $context = []): mixed
    {
        foreach ($data as &$row) {
            $cart = $row[0];
            $cart->totalQuantity = $row['totalQuantity'] ?? 0;
            $row = $cart;
        }

        return $data;
    }
}

With paginationEnabled: false the GraphQL query returns a plain list:

{
    carts {
        totalQuantity
    }
}

With pagination enabled (the default), it returns a Relay connection:

{
    carts {
        edges {
            node {
                totalQuantity
            }
        }
    }
}

# Registering Services Without Autowiring (only for the Symfony variant)

The services in the previous examples are automatically registered because autowiring and autoconfiguration are enabled by default in API Platform. To declare the service explicitly, you can use the following snippet:

# api/config/services.yaml

services:
    # ...
    App\State\BlogPostProvider:
        tags: [ 'api_platform.state_provider' ]

# api/config/services.yaml
services:
    # ...
    App\State\BookRepresentationProvider:
        arguments:
            $itemProvider: '@api_platform.doctrine.orm.state.item_provider'
        tags: [ 'api_platform.state_provider' ]

Using an AI coding agent? See the documentation index for LLMs at /docs/llms.txt.