diff --git a/framework/core/src/Api/Endpoint/Concerns/ShowsResources.php b/framework/core/src/Api/Endpoint/Concerns/ShowsResources.php
new file mode 100644
index 000000000..637c5d7cd
--- /dev/null
+++ b/framework/core/src/Api/Endpoint/Concerns/ShowsResources.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Flarum\Api\Endpoint\Concerns;
+
+use Flarum\Api\Serializer;
+use Tobyz\JsonApiServer\Context;
+use Tobyz\JsonApiServer\Endpoint\Concerns\IncludesData;
+use Tobyz\JsonApiServer\Schema\Concerns\HasMeta;
+
+trait ShowsResources
+{
+    use HasMeta;
+    use IncludesData;
+
+    protected function showResource(Context $context, mixed $model): array
+    {
+        $serializer = new Serializer($context);
+
+        $serializer->addPrimary(
+            $context->resource($context->collection->resource($model, $context)),
+            $model,
+            $this->getInclude($context),
+        );
+
+        [$primary, $included] = $serializer->serialize();
+
+        $document = ['data' => $primary[0]];
+
+        if (count($included)) {
+            $document['included'] = $included;
+        }
+
+        if ($meta = $this->serializeMeta($context)) {
+            $document['meta'] = $meta;
+        }
+
+        return $document;
+    }
+}
diff --git a/framework/core/src/Api/Endpoint/Create.php b/framework/core/src/Api/Endpoint/Create.php
index 44ef17b01..37fb67ea6 100644
--- a/framework/core/src/Api/Endpoint/Create.php
+++ b/framework/core/src/Api/Endpoint/Create.php
@@ -14,9 +14,9 @@ use Flarum\Api\Endpoint\Concerns\HasAuthorization;
 use Flarum\Api\Endpoint\Concerns\HasCustomHooks;
 use Flarum\Api\Endpoint\Concerns\IncludesData;
 use Flarum\Api\Endpoint\Concerns\SavesAndValidatesData;
+use Flarum\Api\Endpoint\Concerns\ShowsResources;
 use Flarum\Database\Eloquent\Collection;
 use RuntimeException;
-use Tobyz\JsonApiServer\Endpoint\Concerns\ShowsResources;
 use Tobyz\JsonApiServer\Resource\Creatable;
 
 use function Tobyz\JsonApiServer\has_value;
diff --git a/framework/core/src/Api/Endpoint/Endpoint.php b/framework/core/src/Api/Endpoint/Endpoint.php
index ba93e913e..31e21c9c9 100644
--- a/framework/core/src/Api/Endpoint/Endpoint.php
+++ b/framework/core/src/Api/Endpoint/Endpoint.php
@@ -15,10 +15,10 @@ use Flarum\Api\Endpoint\Concerns\ExtractsListingParams;
 use Flarum\Api\Endpoint\Concerns\HasAuthorization;
 use Flarum\Api\Endpoint\Concerns\HasCustomHooks;
 use Flarum\Api\Endpoint\Concerns\HasEagerLoading;
+use Flarum\Api\Endpoint\Concerns\ShowsResources;
 use Psr\Http\Message\ResponseInterface as Response;
 use RuntimeException;
 use Tobyz\JsonApiServer\Endpoint\Concerns\FindsResources;
-use Tobyz\JsonApiServer\Endpoint\Concerns\ShowsResources;
 use Tobyz\JsonApiServer\Exception\ForbiddenException;
 use Tobyz\JsonApiServer\Exception\MethodNotAllowedException;
 
diff --git a/framework/core/src/Api/Endpoint/Index.php b/framework/core/src/Api/Endpoint/Index.php
index 3820d1ca6..294ed34dc 100644
--- a/framework/core/src/Api/Endpoint/Index.php
+++ b/framework/core/src/Api/Endpoint/Index.php
@@ -17,6 +17,7 @@ use Flarum\Api\Endpoint\Concerns\HasCustomHooks;
 use Flarum\Api\Endpoint\Concerns\IncludesData;
 use Flarum\Api\Resource\Contracts\Countable;
 use Flarum\Api\Resource\Contracts\Listable;
+use Flarum\Api\Serializer;
 use Flarum\Database\Eloquent\Collection;
 use Flarum\Search\SearchCriteria;
 use Flarum\Search\SearchManager;
@@ -28,7 +29,6 @@ use Tobyz\JsonApiServer\Exception\Sourceable;
 use Tobyz\JsonApiServer\Pagination\OffsetPagination;
 use Tobyz\JsonApiServer\Pagination\Pagination;
 use Tobyz\JsonApiServer\Schema\Concerns\HasMeta;
-use Tobyz\JsonApiServer\Serializer;
 
 use function Tobyz\JsonApiServer\apply_filters;
 use function Tobyz\JsonApiServer\json_api_response;
diff --git a/framework/core/src/Api/Endpoint/Show.php b/framework/core/src/Api/Endpoint/Show.php
index c8d655b03..7c957ea6a 100644
--- a/framework/core/src/Api/Endpoint/Show.php
+++ b/framework/core/src/Api/Endpoint/Show.php
@@ -14,8 +14,8 @@ use Flarum\Api\Endpoint\Concerns\ExtractsListingParams;
 use Flarum\Api\Endpoint\Concerns\HasAuthorization;
 use Flarum\Api\Endpoint\Concerns\HasCustomHooks;
 use Flarum\Api\Endpoint\Concerns\IncludesData;
+use Flarum\Api\Endpoint\Concerns\ShowsResources;
 use Flarum\Database\Eloquent\Collection;
-use Tobyz\JsonApiServer\Endpoint\Concerns\ShowsResources;
 
 class Show extends Endpoint
 {
diff --git a/framework/core/src/Api/Endpoint/Update.php b/framework/core/src/Api/Endpoint/Update.php
index b37cf110e..d78660a75 100644
--- a/framework/core/src/Api/Endpoint/Update.php
+++ b/framework/core/src/Api/Endpoint/Update.php
@@ -14,9 +14,9 @@ use Flarum\Api\Endpoint\Concerns\HasAuthorization;
 use Flarum\Api\Endpoint\Concerns\HasCustomHooks;
 use Flarum\Api\Endpoint\Concerns\IncludesData;
 use Flarum\Api\Endpoint\Concerns\SavesAndValidatesData;
+use Flarum\Api\Endpoint\Concerns\ShowsResources;
 use Flarum\Database\Eloquent\Collection;
 use RuntimeException;
-use Tobyz\JsonApiServer\Endpoint\Concerns\ShowsResources;
 use Tobyz\JsonApiServer\Resource\Updatable;
 
 class Update extends Endpoint
diff --git a/framework/core/src/Api/Serializer.php b/framework/core/src/Api/Serializer.php
new file mode 100644
index 000000000..33d6f6332
--- /dev/null
+++ b/framework/core/src/Api/Serializer.php
@@ -0,0 +1,196 @@
+<?php
+
+namespace Flarum\Api;
+
+use Closure;
+use Illuminate\Support\Collection;
+use RuntimeException;
+use Tobyz\JsonApiServer\Context;
+use Tobyz\JsonApiServer\Resource\Resource;
+use Tobyz\JsonApiServer\Schema\Field\Relationship;
+use function Tobyz\JsonApiServer\has_value;
+use function Tobyz\JsonApiServer\set_value;
+
+class Serializer extends \Tobyz\JsonApiServer\Serializer
+{
+    private Context $context;
+    private array $map = [];
+    private array $primary = [];
+    private Collection $deferred;
+
+    public function __construct(Context $context)
+    {
+        $this->context = $context->withSerializer($this);
+        $this->deferred = new Collection();
+
+        parent::__construct($context);
+    }
+
+    /**
+     * Add a primary resource to the document.
+     */
+    public function addPrimary(Resource $resource, mixed $model, array $include): void
+    {
+        $data = $this->addToMap($resource, $model, $include);
+
+        $this->primary[] = $this->key($data['type'], $data['id']);
+    }
+
+    /**
+     * Serialize the primary and included resources into a JSON:API resource objects.
+     *
+     * @return array{array[], array[]} A tuple with primary resources and included resources.
+     */
+    public function serialize(): array
+    {
+        $this->resolveDeferred();
+
+        $keys = array_flip($this->primary);
+        $primary = array_values(array_intersect_key($this->map, $keys));
+        $included = array_values(array_diff_key($this->map, $keys));
+
+        return [$primary, $included];
+    }
+
+    private function addToMap(Resource $resource, mixed $model, array $include): array
+    {
+        $context = $this->context->withResource($resource)->withModel($model);
+
+        $key = $this->key($type = $resource->type(), $id = $resource->getId($model, $context));
+
+        $url = "{$context->api->basePath}/$type/$id";
+
+        if (!isset($this->map[$key])) {
+            $this->map[$key] = [
+                'type' => $type,
+                'id' => $id,
+                'links' => [
+                    'self' => $url,
+                ],
+            ];
+        }
+
+        foreach ($this->context->sparseFields($resource) as $field) {
+            if (has_value($this->map[$key], $field)) {
+                continue;
+            }
+
+            $context = $context->withField($field)->withInclude($include[$field->name] ?? null);
+
+            if (!$field->isVisible($context)) {
+                continue;
+            }
+
+            $value = $field->getValue($context);
+
+            $this->whenResolved($value, function (mixed $value) use ($key, $field, $context) {
+                if (
+                    ($value = $field->serializeValue($value, $context)) ||
+                    !$field instanceof Relationship
+                ) {
+                    set_value($this->map[$key], $field, $value);
+                }
+            }, $field instanceof Relationship);
+        }
+
+        // TODO: cache
+        foreach ($resource->meta() as $field) {
+            if (!$field->isVisible($context)) {
+                continue;
+            }
+
+            $value = $field->getValue($context);
+
+            $this->whenResolved($value, function (mixed $value) use ($key, $field, $context) {
+                $this->map[$key]['meta'][$field->name] = $field->serializeValue($value, $context);
+            });
+        }
+
+        return $this->map[$key];
+    }
+
+    private function key(string $type, string $id): string
+    {
+        return "$type:$id";
+    }
+
+    private function whenResolved($value, $callback, bool $prepend = false): void
+    {
+        if ($value instanceof Closure) {
+            $callable = fn() => $this->whenResolved($value(), $callback);
+
+            if ($prepend) {
+                $this->deferred->prepend($callable);
+            } else {
+                $this->deferred->push($callable);
+            }
+
+            return;
+        }
+
+        $callback($value);
+    }
+
+    /**
+     * Add an included resource to the document.
+     *
+     * @return array The resource identifier which can be used for linkage.
+     */
+    public function addIncluded(Relationship $field, $model, ?array $include): array
+    {
+        if (is_object($model)) {
+            $relatedResource = $this->resourceForModel($field, $model);
+
+            if ($include === null) {
+                return [
+                    'type' => $relatedResource->type(),
+                    'id' => $relatedResource->getId($model, $this->context),
+                ];
+            }
+
+            $data = $this->addToMap($relatedResource, $model, $include);
+        } else {
+            $data = [
+                'type' => $field->collections[0],
+                'id' => (string) $model,
+            ];
+        }
+
+        return [
+            'type' => $data['type'],
+            'id' => $data['id'],
+        ];
+    }
+
+    private function resourceForModel(Relationship $field, $model): Resource
+    {
+        foreach ($field->collections as $name) {
+            $collection = $this->context->api->getCollection($name);
+
+            if ($type = $collection->resource($model, $this->context)) {
+                return $this->context->api->getResource($type);
+            }
+        }
+
+        throw new RuntimeException(
+            'No resource type defined to represent model ' . get_class($model),
+        );
+    }
+
+    private function resolveDeferred(): void
+    {
+        $i = 0;
+        while ($this->deferred->count()) {
+            $deferred = $this->deferred;
+
+            /** @var Closure $resolve */
+            while ($resolve = $deferred->shift()) {
+                $resolve();
+            }
+
+            if ($i++ > 10) {
+                throw new RuntimeException('Too many levels of deferred values');
+            }
+        }
+    }
+}