add account balances with some random data

app/Http/Controllers/Api/V3/Controllers/AccountController.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace FireflyIII\Http\Controllers\Api\V3\Controllers;
+
+use FireflyIII\Http\Controllers\Controller;
+use FireflyIII\JsonApi\V3\AccountBalances\AccountBalanceSchema;
+use FireflyIII\Models\Account;
+use Illuminate\Contracts\Support\Responsable;
+use LaravelJsonApi\Core\Facades\JsonApi;
+use LaravelJsonApi\Core\Responses\DataResponse;
+use LaravelJsonApi\Laravel\Http\Controllers\Actions;
+use LaravelJsonApi\Laravel\Http\Requests\AnonymousQuery;
+
+class AccountController extends Controller
+{
+
+    use Actions\FetchMany;
+    use Actions\FetchOne;
+    use Actions\Store;
+    use Actions\Update;
+    use Actions\Destroy;
+    use Actions\FetchRelated;
+    use Actions\FetchRelationship;
+    use Actions\UpdateRelationship;
+    use Actions\AttachRelationship;
+    use Actions\DetachRelationship;
+
+    public function readAccountBalances(AnonymousQuery $query, AccountBalanceSchema $schema, Account $account): Responsable
+    {
+        $schema = JsonApi::server()->schemas()->schemaFor('account-balances');
+
+        $models = $schema
+            ->repository()
+            ->queryAll()
+            ->withRequest($query)
+            ->withAccount($account)
+            ->get();
+
+        return DataResponse::make($models);
+    }
+}