diff --git a/app/Api/V1/Controllers/Models/Category/ShowController.php b/app/Api/V1/Controllers/Models/Category/ShowController.php
index 6210a18a87..080ea5c79b 100644
--- a/app/Api/V1/Controllers/Models/Category/ShowController.php
+++ b/app/Api/V1/Controllers/Models/Category/ShowController.php
@@ -28,7 +28,9 @@ use FireflyIII\Api\V1\Controllers\Controller;
 use FireflyIII\Exceptions\FireflyException;
 use FireflyIII\Models\Category;
 use FireflyIII\Repositories\Category\CategoryRepositoryInterface;
+use FireflyIII\Support\JsonApi\Enrichments\CategoryEnrichment;
 use FireflyIII\Transformers\CategoryTransformer;
+use FireflyIII\User;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Pagination\LengthAwarePaginator;
 use League\Fractal\Pagination\IlluminatePaginatorAdapter;
@@ -78,6 +80,15 @@ class ShowController extends Controller
         $count       = $collection->count();
         $categories  = $collection->slice(($this->parameters->get('page') - 1) * $pageSize, $pageSize);
 
+        // enrich
+        /** @var User $admin */
+        $admin       = auth()->user();
+        $enrichment  = new CategoryEnrichment();
+        $enrichment->setUser($admin);
+        $enrichment->setStart($this->parameters->get('start'));
+        $enrichment->setEnd($this->parameters->get('end'));
+        $categories     = $enrichment->enrich($categories);
+
         // make paginator:
         $paginator   = new LengthAwarePaginator($categories, $count, $pageSize, $this->parameters->get('page'));
         $paginator->setPath(route('api.v1.categories.index').$this->buildParams());
@@ -105,6 +116,15 @@ class ShowController extends Controller
         $transformer = app(CategoryTransformer::class);
         $transformer->setParameters($this->parameters);
 
+        // enrich
+        /** @var User $admin */
+        $admin       = auth()->user();
+        $enrichment  = new CategoryEnrichment();
+        $enrichment->setUser($admin);
+        $enrichment->setStart($this->parameters->get('start'));
+        $enrichment->setEnd($this->parameters->get('end'));
+        $category     = $enrichment->enrichSingle($category);
+
         $resource    = new Item($category, $transformer, 'categories');
 
         return response()->json($manager->createData($resource)->toArray())->header('Content-Type', self::CONTENT_TYPE);
diff --git a/app/Repositories/Category/OperationsRepository.php b/app/Repositories/Category/OperationsRepository.php
index 19d76502a9..1c1b9ebb8d 100644
--- a/app/Repositories/Category/OperationsRepository.php
+++ b/app/Repositories/Category/OperationsRepository.php
@@ -27,6 +27,7 @@ namespace FireflyIII\Repositories\Category;
 use Carbon\Carbon;
 use FireflyIII\Enums\TransactionTypeEnum;
 use FireflyIII\Helpers\Collector\GroupCollectorInterface;
+use FireflyIII\Models\Category;
 use FireflyIII\Support\Facades\Amount;
 use FireflyIII\Support\Report\Summarizer\TransactionSummarizer;
 use FireflyIII\Support\Repositories\UserGroup\UserGroupInterface;
@@ -444,4 +445,71 @@ class OperationsRepository implements OperationsRepositoryInterface, UserGroupIn
 
         return $array;
     }
+
+    public function collectExpenses(Carbon $start, Carbon $end, ?Collection $accounts = null, ?Collection $categories = null): array
+    {
+        /** @var GroupCollectorInterface $collector */
+        $collector  = app(GroupCollectorInterface::class);
+        $collector->setUser($this->user)->setRange($start, $end)->setTypes([TransactionTypeEnum::WITHDRAWAL->value]);
+
+        if ($accounts instanceof Collection && $accounts->count() > 0) {
+            $collector->setAccounts($accounts);
+        }
+        if (!$categories instanceof Collection || 0 === $categories->count()) {
+            $categories = $this->getCategories();
+        }
+        $collector->setCategories($categories);
+        $collector->withCategoryInformation();
+        return $collector->getExtractedJournals();
+    }
+
+    public function collectIncome(Carbon $start, Carbon $end, ?Collection $accounts = null, ?Collection $categories = null): array
+    {
+        /** @var GroupCollectorInterface $collector */
+        $collector        = app(GroupCollectorInterface::class);
+        $collector->setUser($this->user)->setRange($start, $end)
+                  ->setTypes([TransactionTypeEnum::DEPOSIT->value])
+        ;
+
+        if ($accounts instanceof Collection && $accounts->count() > 0) {
+            $collector->setAccounts($accounts);
+        }
+        if (!$categories instanceof Collection || 0 === $categories->count()) {
+            $categories = $this->getCategories();
+        }
+        $collector->setCategories($categories);
+        return $collector->getExtractedJournals();
+    }
+
+    public function collectTransfers(Carbon $start, Carbon $end, ?Collection $accounts = null, ?Collection $categories = null): array
+    {
+        /** @var GroupCollectorInterface $collector */
+        $collector = app(GroupCollectorInterface::class);
+        $collector->setUser($this->user)->setRange($start, $end)
+                  ->setTypes([TransactionTypeEnum::TRANSFER->value])
+        ;
+
+        if ($accounts instanceof Collection && $accounts->count() > 0) {
+            $collector->setAccounts($accounts);
+        }
+        if (!$categories instanceof Collection || 0 === $categories->count()) {
+            $categories = $this->getCategories();
+        }
+        $collector->setCategories($categories);
+        return $collector->getExtractedJournals();
+    }
+
+    public function sumCollectedTransactionsByCategory(array $expenses, Category $category, string $method, bool $convertToPrimary = false): array
+    {
+        Log::debug(sprintf('Start of %s.', __METHOD__));
+        $summarizer = new TransactionSummarizer($this->user);
+        $summarizer->setConvertToPrimary($convertToPrimary);
+
+        // filter $journals by range AND currency if it is present.
+        $expenses   = array_filter($expenses, static function (array $expense) use ($category): bool {
+            return $expense['category_id'] === $category->id;
+        });
+
+        return $summarizer->groupByCurrencyId($expenses, $method, false);
+    }
 }
diff --git a/app/Repositories/Category/OperationsRepositoryInterface.php b/app/Repositories/Category/OperationsRepositoryInterface.php
index 6ff6d9bf78..689a7ec875 100644
--- a/app/Repositories/Category/OperationsRepositoryInterface.php
+++ b/app/Repositories/Category/OperationsRepositoryInterface.php
@@ -26,6 +26,8 @@ namespace FireflyIII\Repositories\Category;
 
 use Carbon\Carbon;
 use FireflyIII\Enums\UserRoleEnum;
+use FireflyIII\Models\Category;
+use FireflyIII\Models\TransactionCurrency;
 use FireflyIII\Models\UserGroup;
 use FireflyIII\User;
 use Illuminate\Contracts\Auth\Authenticatable;
@@ -78,6 +80,11 @@ interface OperationsRepositoryInterface
      */
     public function sumExpenses(Carbon $start, Carbon $end, ?Collection $accounts = null, ?Collection $categories = null): array;
 
+    public function collectExpenses(Carbon $start, Carbon $end, ?Collection $accounts = null, ?Collection $categories = null): array;
+    public function collectIncome(Carbon $start, Carbon $end, ?Collection $accounts = null, ?Collection $categories = null): array;
+    public function collectTransfers(Carbon $start, Carbon $end, ?Collection $accounts = null, ?Collection $categories = null): array;
+    public function sumCollectedTransactionsByCategory(array $expenses, Category $category, string $method, bool $convertToPrimary = false): array;
+
     /**
      * Sum of income journals in period for a set of categories, grouped per currency. Amounts are always positive.
      */
diff --git a/app/Support/JsonApi/Enrichments/BudgetEnrichment.php b/app/Support/JsonApi/Enrichments/BudgetEnrichment.php
index 2de1eb1156..d25c12fd4e 100644
--- a/app/Support/JsonApi/Enrichments/BudgetEnrichment.php
+++ b/app/Support/JsonApi/Enrichments/BudgetEnrichment.php
@@ -77,6 +77,7 @@ class BudgetEnrichment implements EnrichmentInterface
         foreach ($this->collection as $budget) {
             $this->ids[] = (int)$budget->id;
         }
+        $this->ids = array_unique($this->ids);
     }
 
     private function collectNotes(): void
diff --git a/app/Support/JsonApi/Enrichments/CategoryEnrichment.php b/app/Support/JsonApi/Enrichments/CategoryEnrichment.php
new file mode 100644
index 0000000000..128bb10b92
--- /dev/null
+++ b/app/Support/JsonApi/Enrichments/CategoryEnrichment.php
@@ -0,0 +1,134 @@
+<?php
+
+namespace FireflyIII\Support\JsonApi\Enrichments;
+
+use Carbon\Carbon;
+use FireflyIII\Models\Category;
+use FireflyIII\Models\Note;
+use FireflyIII\Models\UserGroup;
+use FireflyIII\Repositories\Category\OperationsRepositoryInterface;
+use FireflyIII\User;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Collection;
+use Illuminate\Support\Facades\Log;
+
+class CategoryEnrichment implements EnrichmentInterface
+{
+    private Collection $collection;
+    private User       $user;
+    private UserGroup  $userGroup;
+    private array      $ids         = [];
+    private array      $notes       = [];
+    private ?Carbon    $start       = null;
+    private ?Carbon    $end         = null;
+    private array      $spent       = [];
+    private array      $pcSpent     = [];
+    private array      $earned      = [];
+    private array      $pcEarned    = [];
+    private array      $transfers   = [];
+    private array      $pcTransfers = [];
+
+    public function enrich(Collection $collection): Collection
+    {
+        $this->collection = $collection;
+        $this->collectIds();
+        $this->collectNotes();
+        $this->collectTransactions();
+        $this->appendCollectedData();
+
+        return $collection;
+    }
+
+    public function enrichSingle(Model|array $model): array|Model
+    {
+        Log::debug(__METHOD__);
+        $collection = new Collection([$model]);
+        $collection = $this->enrich($collection);
+
+        return $collection->first();
+    }
+
+    public function setUser(User $user): void
+    {
+        $this->user = $user;
+        $this->setUserGroup($user->userGroup);
+    }
+
+    public function setUserGroup(UserGroup $userGroup): void
+    {
+        $this->userGroup = $userGroup;
+    }
+
+    private function collectIds(): void
+    {
+        /** @var Category $category */
+        foreach ($this->collection as $category) {
+            $this->ids[] = (int)$category->id;
+        }
+        $this->ids = array_unique($this->ids);
+    }
+
+    private function appendCollectedData(): void
+    {
+        $this->collection = $this->collection->map(function (Category $item) {
+            $id         = (int)$item->id;
+            $meta       = [
+                'notes'        => $this->notes[$id] ?? null,
+                'spent'        => $this->spent[$id] ?? null,
+                'pc_spent'     => $this->pcSpent[$id] ?? null,
+                'earned'       => $this->earned[$id] ?? null,
+                'pc_earned'    => $this->pcEarned[$id] ?? null,
+                'transfers'    => $this->transfers[$id] ?? null,
+                'pc_transfers' => $this->pcTransfers[$id] ?? null,
+            ];
+            $item->meta = $meta;
+
+            return $item;
+        });
+    }
+
+    public function setEnd(?Carbon $end): void
+    {
+        $this->end = $end;
+    }
+
+    public function setStart(?Carbon $start): void
+    {
+        $this->start = $start;
+    }
+
+    private function collectNotes(): void
+    {
+        $notes = Note::query()->whereIn('noteable_id', $this->ids)
+                     ->whereNotNull('notes.text')
+                     ->where('notes.text', '!=', '')
+                     ->where('noteable_type', Category::class)->get(['notes.noteable_id', 'notes.text'])->toArray();
+        foreach ($notes as $note) {
+            $this->notes[(int)$note['noteable_id']] = (string)$note['text'];
+        }
+        Log::debug(sprintf('Enrich with %d note(s)', count($this->notes)));
+    }
+
+    private function collectTransactions(): void
+    {
+        if (null !== $this->start && null !== $this->end) {
+            /** @var OperationsRepositoryInterface $opsRepository */
+            $opsRepository = app(OperationsRepositoryInterface::class);
+            $opsRepository->setUser($this->user);
+            $opsRepository->setUserGroup($this->userGroup);
+            $expenses  = $opsRepository->collectExpenses($this->start, $this->end, null, $this->collection);
+            $income    = $opsRepository->collectIncome($this->start, $this->end, null, $this->collection);
+            $transfers = $opsRepository->collectTransfers($this->start, $this->end, null, $this->collection);
+            foreach ($this->collection as $item) {
+                $id                     = (int)$item->id;
+                $this->spent[$id]       = array_values($opsRepository->sumCollectedTransactionsByCategory($expenses, $item, 'negative', false));
+                $this->pcSpent[$id]     = array_values($opsRepository->sumCollectedTransactionsByCategory($expenses, $item, 'negative', true));
+                $this->earned[$id]      = array_values($opsRepository->sumCollectedTransactionsByCategory($income, $item, 'positive', false));
+                $this->pcEarned[$id]    = array_values($opsRepository->sumCollectedTransactionsByCategory($income, $item, 'positive', true));
+                $this->transfers[$id]   = array_values($opsRepository->sumCollectedTransactionsByCategory($transfers, $item, 'positive', false));
+                $this->pcTransfers[$id] = array_values($opsRepository->sumCollectedTransactionsByCategory($transfers, $item, 'positive', true));
+            }
+        }
+    }
+
+}
diff --git a/app/Transformers/BudgetTransformer.php b/app/Transformers/BudgetTransformer.php
index 1c7d085372..35c4d6c6a9 100644
--- a/app/Transformers/BudgetTransformer.php
+++ b/app/Transformers/BudgetTransformer.php
@@ -103,8 +103,8 @@ class BudgetTransformer extends AbstractTransformer
 
             'auto_budget_amount'              => $abAmount,
             'pc_auto_budget_amount'           => $abPrimary,
-            'spent'                           => $this->beautify($budget->meta['spent']), // always in primary currency.
-            'pc_spent'                        => $this->beautify($budget->meta['pc_spent']), // always in primary currency.
+            'spent'                           => $this->beautify($budget->meta['spent']),
+            'pc_spent'                        => $this->beautify($budget->meta['pc_spent']),
             'links'                           => [
                 [
                     'rel' => 'self',
diff --git a/app/Transformers/CategoryTransformer.php b/app/Transformers/CategoryTransformer.php
index 19b26b2d11..d6d93ca636 100644
--- a/app/Transformers/CategoryTransformer.php
+++ b/app/Transformers/CategoryTransformer.php
@@ -26,30 +26,22 @@ namespace FireflyIII\Transformers;
 
 use FireflyIII\Models\Category;
 use FireflyIII\Models\TransactionCurrency;
-use FireflyIII\Repositories\Category\CategoryRepositoryInterface;
-use FireflyIII\Repositories\Category\OperationsRepositoryInterface;
 use FireflyIII\Support\Facades\Amount;
-use Illuminate\Support\Collection;
+use FireflyIII\Support\Facades\Steam;
 
 /**
  * Class CategoryTransformer
  */
 class CategoryTransformer extends AbstractTransformer
 {
-    private readonly bool                          $convertToNative;
-    private readonly TransactionCurrency           $primary;
-    private readonly OperationsRepositoryInterface $opsRepository;
-    private readonly CategoryRepositoryInterface   $repository;
+    private readonly TransactionCurrency $primaryCurrency;
 
     /**
      * CategoryTransformer constructor.
      */
     public function __construct()
     {
-        $this->opsRepository   = app(OperationsRepositoryInterface::class);
-        $this->repository      = app(CategoryRepositoryInterface::class);
-        $this->primary         = Amount::getPrimaryCurrency();
-        $this->convertToNative = Amount::convertToPrimary();
+        $this->primaryCurrency = Amount::getPrimaryCurrency();
     }
 
     /**
@@ -57,39 +49,32 @@ class CategoryTransformer extends AbstractTransformer
      */
     public function transform(Category $category): array
     {
-        $this->opsRepository->setUser($category->user);
-        $this->repository->setUser($category->user);
-
-        $spent   = [];
-        $earned  = [];
-        $start   = $this->parameters->get('start');
-        $end     = $this->parameters->get('end');
-        if (null !== $start && null !== $end) {
-            $earned = $this->beautify($this->opsRepository->sumIncome($start, $end, null, new Collection([$category])));
-            $spent  = $this->beautify($this->opsRepository->sumExpenses($start, $end, null, new Collection([$category])));
-        }
-        $primary = $this->primary;
-        if (!$this->convertToNative) {
-            $primary = null;
-        }
-        $notes   = $this->repository->getNoteText($category);
 
         return [
-            'id'                              => $category->id,
-            'created_at'                      => $category->created_at->toAtomString(),
-            'updated_at'                      => $category->updated_at->toAtomString(),
-            'name'                            => $category->name,
-            'notes'                           => $notes,
-            'primary_currency_id'             => $primary instanceof TransactionCurrency ? (string)$primary->id : null,
-            'primary_currency_code'           => $primary?->code,
-            'primary_currency_symbol'         => $primary?->symbol,
-            'primary_currency_decimal_places' => $primary?->decimal_places,
-            'spent'                           => $spent,
-            'earned'                          => $earned,
+            'id'                          => $category->id,
+            'created_at'                  => $category->created_at->toAtomString(),
+            'updated_at'                  => $category->updated_at->toAtomString(),
+            'name'                        => $category->name,
+            'notes'                       => $category->meta['notes'],
+
+            // category never has currency settings.
+            'object_has_currency_setting' => false,
+
+
+            'primary_currency_id'             => (string)$this->primaryCurrency->id,
+            'primary_currency_code'           => $this->primaryCurrency->code,
+            'primary_currency_symbol'         => $this->primaryCurrency->symbol,
+            'primary_currency_decimal_places' => (int)$this->primaryCurrency->decimal_places,
+            'spent'                           => $this->beautify($category->meta['spent']),
+            'pc_spent'                        => $this->beautify($category->meta['pc_spent']),
+            'earned'                          => $this->beautify($category->meta['earned']),
+            'pc_earned'                       => $this->beautify($category->meta['pc_earned']),
+            'transferred'                     => $this->beautify($category->meta['transfers']),
+            'pc_transferred'                  => $this->beautify($category->meta['pc_transfers']),
             'links'                           => [
                 [
                     'rel' => 'self',
-                    'uri' => '/categories/'.$category->id,
+                    'uri' => '/categories/' . $category->id,
                 ],
             ],
         ];