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Version: 2.x

API and Data Flow

In the previous article, we learned how Flarum uses models to interact with data. Here, we'll learn how to get that data from the database to the JSON-API to the frontend, and all the way back again.

info

To use the built-in REST API as part of an integration, see Consuming the REST API.

API Request Lifecycle​

Before we go into detail about how to extend Flarum's data API, it's worth thinking about the lifecycle of a typical API request:

Flarum API Flowchart

  1. An HTTP request is sent to Flarum's API. Typically, this will come from the Flarum frontend, but external programs can also interact with the API. Flarum's API mostly follows the JSON:API specification, so accordingly, requests should follow said specification.
  2. The request is run through middleware, and routed to the proper API resource endpoint. Each API Resource is distinguished by a unique type and has a set of endpoints. You can read more about them in the below sections.
  3. Any modifications done by extensions to the API Resource endpoints via the ApiResource extender are applied. This could entail changing sort, adding includes, eager loading relations, or executing some logic before and/or after the default implementation runs.
  4. The action of the endpoint is called, yielding some raw data that should be returned to the client. Typically, this data will take the form of a Laravel Eloquent model collection or instance, which has been retrieved from the database. That being said, the data could be anything as long as the API resource can process it. There are built-in reusable endpoint for CRUD operations, but custom endpoints can be implemented as well.
  5. Any modifications made through the ApiResource extender to the API resource's fields will be applied. These can include adding new attributes or relationships to serialize, removing existing ones, or changing how the field value is computed.
  6. The fields (attributes and relationships) are serialized, converting the data from the backend database-friendly format to the JSON:API format expected by the frontend.
  7. The serialized data is returned as a JSON response to the frontend.
  8. If the request originated via the Flarum frontend's Store, the returned data (including any related objects) will be stored as frontend models in the frontend store.

API Resources​

We learned how to use models to interact with data, but we still need to get that data from the backend to the frontend. We do this by writing an API Resource for the model, which defines the fields (attributes and relationships) of the model, the endpoints of the resource API, and optionally some extra logic, such as visibility scoping, sorting options, etc. We will learn about this in the next few sections.

CRUD endpoints are provided by Flarum, so you can simply add them to your API resource's endpoints() method. They are:

  • Index: Listing many instances of a model (possibly including searching/filtering)
  • Show: Getting a single model instance
  • Create: Creating a model instance
  • Update: Updating a model instance
  • Delete: Deleting a single model instance
info

Flarum uses a forked version of Toby Zerner's json-api-server. So some of what is documented there applies in Flarum, but not everything is the same.

Flarum CLI

You can use the CLI to automatically create your API resource:

$ flarum-cli make backend api-resource

Example: if you had a Label model, the LabelResource you would create could look something like this:

namespace Acme\Api;

use Acme\Label;
use Flarum\Api\Context;
use Flarum\Api\Endpoint;
use Flarum\Api\Resource\AbstractDatabaseResource;
use Flarum\Api\Schema;

/** @extends AbstractDatabaseResource<Label> */
class LabelResource extends AbstractDatabaseResource
{
    public function type(): string
    {
        return 'labels';
    }

    public function model(): string
    {
        return Label::class;
    }

    public function scope(Builder $query, Context $context): void
    {
        $query->whereVisibleTo($context->getActor());
    }

    public function endpoints(): array
    {
        return [
            Endpoint\Show::make(),
            Endpoint\Create::make()
                ->authenticated()
                ->can('createLabel'),
            Endpoint\Update::make()
                ->authenticated()
                ->can('edit'),
            Endpoint\Delete::make()
                ->authenticated()
                ->can('delete'),
            Endpoint\Index::make()
                ->defaultInclude(['parent']),
        ];
    }

    /*
     * This is only for endpoint processing and serialization.
     * You still have to create a database migration to add the table/columns.
     */
    public function fields(): array
    {
        return [
            Schema\Str::make('name')
                ->requiredOnCreate()
                ->writable(),
            Schema\Str::make('description')
                ->writable()
                ->maxLength(700)
                ->nullable(),
            Schema\Str::make('slug')
                ->requiredOnCreate()
                ->writable()
                ->unique('labels', 'slug', true)
                ->regex('/^[^\/\\ ]*$/i'),
            Schema\Str::make('color')
                ->writable()
                ->nullable()
                ->rule('hex_color'),
            Schema\Str::make('icon')
                ->writable()
                ->nullable(),
            Schema\Boolean::make('isActive')
                ->writable(),
            Schema\DateTime::make('createdAt'),
            Schema\Boolean::make('canAddToDiscussion')
                ->get(fn (Tag $tag, FlarumContext $context) => $context->getActor()->can('addToDiscussion', $tag)),

            Schema\Relationship\ToOne::make('user')
                ->type('users')
                ->includable(),
            Schema\Relationship\ToOne::make('parent')
                ->type('labels')
                ->includable(),
            Schema\Relationship\ToMany::make('children')
                ->type('labels')
                ->includable(),
        ];
    }
    
    public function sorts(): array
    {
        return [
            SortColumn::make('createdAt'),
        ];
    }
}

Resource Definition​

The API resource class must extend the Flarum\Api\Resource\AbstractDatabaseResource class when interacting with Eloquent models, and Flarum\Api\Resource\AbstractResource when not. The type method should return a unique string that identifies the resource type. In the case of a database resource, the model method must return the class name of the model (::class property).

use Flarum\Api\Resource\AbstractDatabaseResource;

class LabelResource extends AbstractDatabaseResource
{
    public function type(): string
    {
        return 'labels';
    }

    public function model(): string
    {
        return Label::class;
    }
}
use Flarum\Api\Resource\AbstractResource;

class CustomResource extends AbstractResource
{
    public function type(): string
    {
        return 'custom';
    }
    
    public function getId(object $model, Context $context): string
    {
        return // return the model ID.
    }

    public function find(string $id, Context $context): ?object
    {
        // return the model instance.
    }
}

Scoping Database Resources​

The scope method is used to apply a query scope to the model. This is useful for applying visibility scoping and ensures no data is returned that the actor should not have access to, including when the resource is a serialized relationship of another resource.

use Tobyz\JsonApiServer\Context;
use Illuminate\Database\Eloquent\Builder;

public function scope(Builder $query, Context $context): void
{
    $query->whereVisibleTo($context->getActor());
}

Listing Resources​

The Index endpoint lists the model instances. 

public function endpoints(): array
{
    return [
        Endpoint\Index::make(),
    ];
}
info

Find out more about the listing endpoint in the underlying package's documentation: https://tobyzerner.github.io/json-api-server/list.html

Pagination​

You can paginate the resources being listed to by specifying the limit and maxLimit through the paginate method:

use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Index::make()
            ->paginate(20, 50), // these are the default values, so you may omit these arguments.
    ];
}

Sorting​

You can specify sort columns through the sorts method. For example the following will permit two sorting options: createdAt (in ascending order) and -createdAt (in descending order):

use Flarum\Api\Sort\SortColumn;

public function sorts(): array
{
    return [
        SortColumn::make('createdAt'),
    ];
}

You can specify the default sort through the defaultSort method on the Index endpoint:

use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Index::make()
            ->defaultSort('-createdAt'),
            ->paginate(),
    ];
}

Searching and Filtering​

Read our searching and filtering guide for more information!

Showing, Creating, Updating, and Deleting Resources​

The Show, Create, Update, and Delete endpoints are used to get, create, update, and delete a single model instance, respectively.

If your resource class extends the AbstractDatabaseResource class, you can directly use the endpoints.

use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Show::make(),
        Endpoint\Create::make(),
        Endpoint\Update::make(),
        Endpoint\Delete::make(),
    ];
}

If your resource class extends the AbstractResource class, you must implement the appropriate interfaces.

use Flarum\Api\Resource\Contracts\{
    Countable,
    Creatable,
    Deletable,
    Findable,
    Listable,
    Paginatable,
    Updatable
};

class CustomResource extends AbstractResource implements
    Findable, // Show endpoint
    Listable, // Index endpoint
    Countable, // Optional for Index endpoints total result count
    Paginatable, // Optional if paginating Index endpoint results
    Creatable, // Create endpoint
    Updatable, // Update endpoint
    Deletable // Delete endpoint
{
    // ...
}
info

Find out more about these endpoint in the underlying package's documentation:

Database resource hooks​

API database resources have additional hooks that can be used to run custom logic:

public function creating(object $model, Context $context): ?object
{
    return $model;
}

public function updating(object $model, Context $context): ?object
{
    return $model;
}

public function saving(object $model, Context $context): ?object
{
    return $model;
}

public function saved(object $model, Context $context): ?object
{
    return $model;
}

public function created(object $model, Context $context): ?object
{
    return $model;
}

public function updated(object $model, Context $context): ?object
{
    return $model;
}

public function deleting(object $model, Context $context): void
{
    //
}

public function deleted(object $model, Context $context): void
{
    //
}

public function mutateDataBeforeValidation(Context $context, array $data): array
{
    return $data;
}

Endpoints​

There is a range of methods you can use to customize the behavior of your API endpoints. We will try to go through them in this section.

Authorization​

You can use a callback to determine whether an actor can access an endpoint. This is done through the visible method on the endpoint:

use Flarum\Api\Context;
use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Show::make()
            ->visible(fn (Label $label, Context $context) => $context->getActor()->can('view', $label)),
    ];
}

Flarum adds a couple of useful methods. The can, authenticated & admin methods. can is just the equivalent of the above example. authenticated checks that the actor is logged in (not a guest). admin checks that the actor is an admin.

use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Show::make()
            ->authenticated()
            ->can('view'), // equivalent to $actor->assertCan('view', $label)
        Endpoint\Create::make()
            ->authenticated()
            ->can('createLabel'), // equivalent to $actor->assertCan('createLabel'),
        Endpoint\Update::make()
            ->admin(), // equivalent to $actor->assertAdmin()
    ];
}

Including relationship by default​

We do not recommend including relationships by default. If possible, it is better to extend the specific request payloads to be made on the frontend side and add the includes there as that keeps the API responses optimized. However, if you really need to include a relationship by default, you can do so through the defaultInclude method:

use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Index::make()
            ->defaultInclude(['parent']),
    ];
}

Lifecycle Hooks​

Some methods on the endpoint allow you to hook certain logic into the lifecycle of the endpoint. These are before, after, and beforeSerialization which is often not very different from after but is called before it when available on the endpoint. For example, you can use these hooks to log additional information (such as marking notifications as read when said endpoint is accessed), or you may need to modify the resulting data before it is serialized.

use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Index::make()
            ->before(function (Context $context) {
                // Do something before the endpoint logic.
            })
            ->after(function (Context $context, mixed $data) {
                // Do something after the endpoint logic.
            })
            ->beforeSerialization(function (Context $context, mixed $results) {
                // Do something before the data is serialized.
            }),
    ];
}

Eager Loading​

By default, relationships that are included in the API response are automatically eager loaded. However, a lot of times you will want to specify some relations to be eager loaded regardless of their inclusion in the API response. For example, if you need to access $label->parent to check that a field should be visible in the response, then you will need to eager load the parent relation to prevent N+1 queries.

You can do this through the eagerLoad, eagerLoadWhenIncluded and eagerLoadWhere methods on the endpoint.

use Flarum\Api\Endpoint;
use Illuminate\Database\Eloquent\Builder;

public function endpoints(): array
{
    return [
        Endpoint\Index::make()
            // will always eager load the parent relation.
            ->eagerLoad(['parent']), 
            // will eager load the parent.user relation only when parent is included in the API response.
            ->eagerLoadWhenIncluded(['parent' => ['parent.user']])
            // will eager load the parent relation only when the parent is active.
            ->eagerLoadWhere('parent', function (Builder $query) {
                $query->where('is_active', true);
            }),
    ];
}
tip

Use the Clockwork extension to profile your API requests and see if you are making N+1 queries. These can be very costly the larger the community is.

Custom Endpoints​

Aside from the built-in CRUD endpoints, you can also define custom endpoints. This is done through the Endpoint\Endpoint class. You can define the logic of the endpoint through the action method. Unlike the built-in CRUD endpoints, you must specify the name of the endpoint, the HTTP method, and path.

If you path includes an {id} parameter, the model will be automatically fetched and can be accessed through $context->model.

If the action method returns null, the API response will be an empty document. If the model is returned, it will be serialized and returned as the API response.

use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Endpoint::make('activate')
            ->route('POST', '/{id}/activate')
            ->action(function (Context $context) {
                $label = $context->model;
                $label->isActive = true;
                $label->save();
                
                return $label;
            }),
    ];
}

Alternatively you can use the response method to customize the response.

use Flarum\Api\Endpoint;

public function endpoints(): array
{
    return [
        Endpoint\Endpoint::make('activate')
            ->route('POST', '/{id}/activate')
            ->action(function (Context $context) {
                return ['information' => 'test'];
            })
            ->response(function (Context $context, array $results) {
                // $results is the return value of the action method.
            
                return new Response(204);
            })
    ];
}

Linking to endpoints internally​

Each resource endpoint registers a route with the name $type.$name. For example, the Index endpoint on the LabelResource will have a route name of labels.index, and the custom activate endpoint will have a route name of labels.activate. You can use the UrlGenerator to generate URLs to these endpoints.

/** @var \Flarum\Http\UrlGenerator $url */
$url->to('api')->route('labels.index');
$url->to('api')->route('labels.activate', ['id' => $label->id]);

Fields (Attributes and Relationships)​

The fields method on the API resource is used to define the fields (attributes and relationships) of the model. You can use the Schema namespace to define the various field types.

The code examples below are methods within an API resource class.

Attributes​

Before you define an attribute, decide which type of attribute it is. The Schema namespace provides a range of attribute types, such as Str, Integer, Boolean, DateTime and Arr for arrays.

use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Str::make('name')
            ->requiredOnCreate()
            ->writable(),
        Schema\Integer::make('discussionCount'),
        Schema\Arr::make('customData'),
        Schema\Boolean::make('isActive')
            ->writable(),
        Schema\DateTime::make('createdAt'),
    ];
}

Visibility​

You can use the visible method to conditionally include an attribute in the API response.

use Flarum\Api\Context;
use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Str::make('name')
            ->visible(fn (Label $label, Context $context) => $context->getActor()->can('edit', $label)),
    ];
}

Writability​

By default, a field is not writable unless you specify it to be so. You can use the writable method to make a field writable.

use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Str::make('name')
            ->writable(),
        Schema\Boolean::make('isActive')
            // If it's only writable on create.
            ->writableOnCreate()
            // If it's only writable on update.
            ->writableOnUpdate(),
    ];
}

Requirability​

By default, a field is not required unless you specify it to be so. You can use the methods required, requiredOnCreate, requiredWith, requiredWithout, requiredOnCreateWith, requiredOnUpdateWith, requiredOnCreateWithout, requiredOnUpdateWithout.

caution

You will normally only want to only require fields on creation so that fields can be updated in isolation of other attributes. So we recommend using requiredOnCreate methods by default unless the need for otherwise arises.

use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Str::make('name')
            ->requiredOnCreate(),
    ];
}

Getter & Setter​

By default, the value will be written directly to the model attribute, and read directly from the model attribute. You can use the get and set methods to customize how the value is read and written.

use Flarum\Api\Context;
use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Str::make('name')
            ->get(fn (Label $label) => strtoupper($label->name))
            ->set(function (Label $label, string $value, Context $context) {
                $label->name = strtolower($value);
            }),
    ];
}

Validation​

You can use the rule method to add a Laravel validation rule to an attribute. We've provided helper methods on some attributes for common validation rules.

use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Str::make('name')
            ->rule('ruleName')
            ->rule('ruleName', false) // will not apply
            ->rule('ruleName', function (Context $context, ?Label $model) {
                return // if the rule should apply.
            })
            ->rule(function (Context $context) {
                return function ($attribute, $value, $fail) {
                    if ($value !== 'foo') {
                        $fail('The '.$attribute.' must be foo.');
                    }
                };
            }, $condition),
    
    
        Schema\Str::make('name')
            ->requiredOnCreate() // only required when creating a new model.
            ->maxLength(255),
        Schema\Str::make('slug')
            ->required() // required on both create and update.
            ->unique('labels', 'slug', true) // unique in the labels table, ignoring the current model.
            ->regex('/^[^\/\\ ]*$/i'), // must match the regex.
        Schema\Str::make('color')
            ->rule('hex_color'),
        Schema\Number::make('price')
            ->min(1)
            ->max(100),
        Schema\DateTime::make('createdAt')
            ->before('2022-01-01')
            ->after('2021-01-01'),
    ];
}

Property​

By default you should use camelCase for your attribute names and they will be automatically mapped to their snake_case equivalent when interacting with the model. But if you need to specify which property on the model the attribute should map to, you can use the property method.

use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Str::make('name')
            ->property('name_column'),
    ];
}

Relationship aggregates​

The Number & Integer attributes are able to get efficiently get relationship aggregates such as counts, sums, max, and min.

use Flarum\Api\Schema\Number;
use Flarum\Api\Schema\Integer;

public function fields(): array
{
    return [
        Integer::make('commentCount')
            ->countRelation('comments'),
        
        Number::make('avgRevenue')
            ->avgReation('reports', 'revenue'),
        
        Number::make('revenueSum')
            ->sumRelation('reports', 'revenue'),
        
        Number::make('minNumber')
            ->minRelation('posts', 'number'),
        
        Number::make('maxNumber')
            ->maxRelation('posts', 'number'),
    ];
}

Relationships​

A relationship is a field, so all that was mentioned about fields above applies to relationships as well.

There are two types of relationships: ToOne and ToMany. You can use the Schema\Relationship\ToOne and Schema\Relationship\ToMany classes to define them.

use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Relationship\ToOne::make('user')
            ->type('users'),
        Schema\Relationship\ToMany::make('children')
            ->type('labels'),
    ];
}

Inclusion & Linkage​

You can mark a relationship as includable through the includable method. This means that the relationship can be included in the API response. You can also use the withLinkage and withoutLinkage methods to determine whether the relationship ID(s) should be included in the API response (ToMany relationships are not linked by default contrary to ToOne relationships).

danger

Adding linkage for ToMany relationships can lead to performance issues as it will include the IDs of all the related models in the API response. This is why it is not linked by default.

use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Relationship\ToOne::make('user')
            ->type('users')
            ->includable()
            ->withoutLinkage(),
    ];
}
tip

Relationship linkage is the ID of the related model(s) in the API response. For example, linkage of a ToOne relationship would look like this:

{
    "attributes": {
        "name": "John Doe"
    },
    "relationships": {
        "user": {
            "data": {
                "type": "users",
                "id": "1"
            }
        }
    }
}

Polymorphic Relationships​

You use the collection method to define the resource types that a polymorphic relationship can point to.

use Flarum\Api\Schema;

public function fields(): array
{
    return [
        Schema\Relationship\ToOne::make('subject')
            ->collection(['users', 'discussions', 'posts']),
    ];
}

Extending API Resources​

Any API Resource can be extended through the ApiResource extender. This is useful for adding new fields, relationships, or endpoints to an existing resource. Or when registering a new resource.

use Flarum\Api\Resource;
use Flarum\Api\Schema;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->fields(fn () => [
            Schema\Str::make('customField'),
            Schema\Relationship\ToOne::make('customRelation')
                ->type('customRelationType'),
        ])
        ->endpoints(fn () => [
            Endpoint\Endpoint::make('custom')
                ->route('GET', '/custom')
                ->action(fn (Context $context) => 'custom'),
        ]),
]

Adding fields​

You can add fields to an existing resource through the fields method.

use Flarum\Api\Resource;
use Flarum\Api\Schema;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->fields(fn () => [
            Schema\Str::make('customField'),
            Schema\Relationship\ToOne::make('customRelation')
                ->type('customRelationType'),
        ])
        ->fieldsBefore('email', fn () => [
            Schema\Str::make('customFieldBeforeEmail'),
        ])
        ->fieldsAfter('email', fn () => [
            Schema\Str::make('customFieldAfterEmail'),
        ]),
]

Mutating an existing field​

You can mutate an existing field through the field method. You must pass the field name as first argument.

use Flarum\Api\Resource;
use Flarum\Api\Schema;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->field('email', function (Schema\Str $field) {
            return $field->get(fn () => 'override@test');
        }),
];

Removing fields​

You can remove fields from an existing resource through the removeField method.

use Flarum\Api\Resource;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->removeField('email'),
];

Adding endpoints​

You can add endpoints to an existing resource through the endpoints method.

use Flarum\Api\Context;
use Flarum\Api\Resource;
use Flarum\Api\Endpoint;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->endpoints(fn () => [
            Endpoint\Endpoint::make('custom')
                ->route('GET', '/{id}/custom')
                ->action(function (Context $context) {
                    $user = $context->model;
                    
                    // logic...
                }),
        ])
        ->endpointsBefore('show', fn () => [
            Endpoint\Endpoint::make('customBeforeShow')
                ->route('GET', '/customBeforeShow')
                ->action(function (Context $context) {
                    // logic ...
                }),
        ])
        ->endpointsAfter('show', fn () => [
            Endpoint\Endpoint::make('customAfterShow')
                ->route('GET', '/customAfterShow')
                ->action(function (Context $context) {
                    // logic ...
                }),
        ])
        ->endpointsBeforeAll(fn () => [
            Endpoint\Endpoint::make('customBeforeAll')
                ->route('GET', '/customBeforeAll')
                ->action(function (Context $context) {
                    // logic ...
                }),
        ])
];

Mutating an existing endpoint​

You can mutate an existing endpoint through the endpoint method. You must pass either the endpoint class name or the endpoint name as first argument. You may pass an array of endpoint class names and/or names.

use Flarum\Api\Resource;
use Flarum\Api\Endpoint;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->endpoint('show', function (Endpoint\Show $endpoint) {
            return $endpoint->visible(fn (User $user, Context $context) => $context->getActor()->can('view', $user));
        })
        ->endpoint(Endpoint\Index::class, function (Endpoint\Index $endpoint) {
            return $endpoint->paginate(20, 50);
        })
        ->endpoint(['create', 'update'], function (Endpoint\Create|Endpoint\Update $endpoint) {
            return $endpoint->authenticated();
        }),
];

Removing endpoints​

You can remove endpoints from an existing resource through the removeEndpoint method.

use Flarum\Api\Resource;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->removeEndpoint('delete'),
];

Adding sort columns​

You can add sort columns to an existing resource through the sorts method.

use Flarum\Api\Resource;
use Flarum\Api\Sort\SortColumn;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->sorts(fn () => [
            SortColumn::make('createdAt'),
        ]),
];

Mutating an existing sort column​

You can mutate an existing sort column through the sort method. You must pass the sort column name as first argument.

use Flarum\Api\Resource;
use Flarum\Api\Sort\SortColumn;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->sort('createdAt', function (SortColumn $sort) {
            return $sort->column('created_at');
        }),
];

Removing sort columns​

You can remove sort columns from an existing resource through the removeSort method.

use Flarum\Api\Resource;
use Flarum\Extend;

return [
    (new Extend\ApiResource(Resource\UserResource::class))
        ->removeSort('createdAt'),
];

Registering a new API Resource​

Simply using the ApiResource extender with your new resource class will register it.

use Acme\Api\LabelResource;
use Flarum\Extend;

return [
    (new Extend\ApiResource(LabelResource::class)),
]

Non-Model API Resources​

API Resources don't have to correspond to Eloquent models: you can define JSON:API resources for anything. You need to extend the Flarum\Api\Rsource\AbstractResource class instead. For instance, Flarum core uses the Flarum\Api\Resource\ForumResource to send an initial payload to the frontend. This can include settings, whether the current user can perform certain actions, and other data. Many extensions add data to the payload by extending the fields of ForumResource.

Programmatically calling an API endpoint​

You can internally execute an endpoint's logic through the Flarum\Api\JsonApi object. For example, this is what Flarum does to immediately create the first post of a discussion:

/** @var JsonApi $api */
$api = $context->api;

/** @var Post $post */
$post = $api->forResource(PostResource::class)
    ->forEndpoint('create')
    ->withRequest($context->request)
    ->process([
        'data' => [
            'attributes' => [
                'content' => Arr::get($context->body(), 'data.attributes.content'),
            ],
            'relationships' => [
                'discussion' => [
                    'data' => [
                        'type' => 'discussions',
                        'id' => (string) $model->id,
                    ],
                ],
            ],
        ],
    ], ['isFirstPost' => true]);

If you do not have access to the Flarum\Api\Context $context object, then you can directly inject the api object:

use Flarum\Api\JsonApi;

public function __construct(
    protected JsonApi $api 
) {
}

public function handle(): void
{
    $group = $api->forResource(GroupResource::class)
        ->forEndpoint('create')
        ->process(
            body: [
                'data' => [
                    'attributes' => [
                        'nameSingular' => 'test group',
                        'namePlural' => 'test groups',
                        'color' => '#000000',
                        'icon' => 'fas fa-crown',
                    ]
                ],
            ],
            options: ['actor' => User::find(1)]
        )
}