diff --git a/src/Api/Enum/InventoryDocumentType.php b/src/Api/Enum/InventoryDocumentType.php
new file mode 100644
index 0000000..6a1f5f0
--- /dev/null
+++ b/src/Api/Enum/InventoryDocumentType.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Baselinker\Api\Enum;
+
+enum InventoryDocumentType: int
+{
+    case GoodsReceived = 0;
+    case InternalGoodsReceived = 1;
+    case GoodsIssue = 2;
+    case InternalGoodsIssue = 3;
+    case InternalTransfer = 4;
+    case OpeningBalance = 5;
+}
diff --git a/src/Api/Enum/InventoryPurchaseOrderStatus.php b/src/Api/Enum/InventoryPurchaseOrderStatus.php
new file mode 100644
index 0000000..bbe1452
--- /dev/null
+++ b/src/Api/Enum/InventoryPurchaseOrderStatus.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Baselinker\Api\Enum;
+
+enum InventoryPurchaseOrderStatus: int
+{
+    case Draft = 0;
+    case Sent = 1;
+    case Received = 2;
+    case Completed = 3;
+    case CompletedPartially = 4;
+    case Canceled = 5;
+}
diff --git a/src/Api/Request/InventoryDocuments.php b/src/Api/Request/InventoryDocuments.php
new file mode 100644
index 0000000..5bc65df
--- /dev/null
+++ b/src/Api/Request/InventoryDocuments.php
@@ -0,0 +1,63 @@
+<?php
+
+namespace Baselinker\Api\Request;
+
+use Baselinker\Api\Client;
+use Baselinker\Api\Enum\InventoryDocumentType;
+use Baselinker\Api\Response\Response;
+
+class InventoryDocuments extends Client
+{
+    public function addInventoryDocument(int $warehouseId, InventoryDocumentType $documentType, array $data = []): Response
+    {
+        $data['warehouse_id'] = $warehouseId;
+        $data['document_type'] = $documentType->value;
+
+        return new Response(
+            $this->post('addInventoryDocument', $data)
+        );
+    }
+
+    public function setInventoryDocumentStatusConfirmed(int $documentId): Response
+    {
+        return new Response(
+            $this->post('setInventoryDocumentStatusConfirmed', [
+                'document_type' => $documentId,
+            ])
+        );
+    }
+
+    public function getInventoryDocuments(array $filters = []): Response
+    {
+        return new Response(
+            $this->post('getInventoryDocuments', $filters)
+        );
+    }
+
+    public function getInventoryDocumentItems(int $documentId, ?int $page = null): Response
+    {
+        return new Response(
+            $this->post('getInventoryDocumentItems', [
+                'document_id' => $documentId,
+                'page' => $page,
+            ])
+        );
+    }
+
+    public function addInventoryDocumentItems(int $documentId, array $items): Response
+    {
+        return new Response(
+            $this->post('addInventoryDocumentItems', [
+                'document_id' => $documentId,
+                'items' => $items,
+            ])
+        );
+    }
+
+    public function getInventoryDocumentSeries(): Response
+    {
+        return new Response(
+            $this->post('getInventoryDocumentSeries')
+        );
+    }
+}
diff --git a/src/Api/Request/InventoryPurchaseOrders.php b/src/Api/Request/InventoryPurchaseOrders.php
new file mode 100644
index 0000000..df45455
--- /dev/null
+++ b/src/Api/Request/InventoryPurchaseOrders.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Baselinker\Api\Request;
+
+use Baselinker\Api\Client;
+use Baselinker\Api\Enum\InventoryPurchaseOrderStatus;
+use Baselinker\Api\Response\Response;
+
+class InventoryPurchaseOrders extends Client
+{
+    public function getInventoryPurchaseOrders(array $data = []): Response
+    {
+        return new Response(
+            $this->post('getInventoryPurchaseOrders', $data),
+        );
+    }
+
+    public function getInventoryPurchaseOrderItems(int $orderId, ?int $page = null): Response
+    {
+        return new Response(
+            $this->post('getInventoryPurchaseOrderItems', [
+                'order_id' => $orderId,
+                'page' => $page,
+            ]),
+        );
+    }
+
+    public function getInventoryPurchaseOrderSeries(int $warehouseId): Response
+    {
+        return new Response(
+            $this->post('getInventoryPurchaseOrderSeries', [
+                'warehouse_id' => $warehouseId,
+            ]),
+        );
+    }
+
+    public function addInventoryPurchaseOrder(int $warehouseId, int $supplierId, int $payerId, string $currency = 'PLN', array $data = []): Response
+    {
+        $data['warehouse_id'] = $warehouseId;
+        $data['supplier_id'] = $supplierId;
+        $data['payer_id'] = $payerId;
+        $data['currency'] = $currency;
+
+        return new Response(
+            $this->post('addInventoryPurchaseOrder', $data),
+        );
+    }
+
+    public function addInventoryPurchaseOrderItems(int $orderId, array $items): Response
+    {
+        return new Response(
+            $this->post('addInventoryPurchaseOrderItems', [
+                'order_id' => $orderId,
+                'items' => $items,
+            ]),
+        );
+    }
+
+    public function setInventoryPurchaseOrderStatus(int $orderId, InventoryPurchaseOrderStatus $status, array $completedItems = []): Response
+    {
+        return new Response(
+            $this->post('setInventoryPurchaseOrderStatus', [
+                'order_id' => $orderId,
+                'status' => $status->value,
+                'completed_items' => $completedItems,
+            ]),
+        );
+    }
+}
diff --git a/src/Api/Request/InventorySuppliers.php b/src/Api/Request/InventorySuppliers.php
new file mode 100644
index 0000000..bced833
--- /dev/null
+++ b/src/Api/Request/InventorySuppliers.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace Baselinker\Api\Request;
+
+use Baselinker\Api\Client;
+use Baselinker\Api\Response\Response;
+
+class InventorySuppliers extends Client
+{
+    public function getInventorySuppliers(array $filters = []): Response
+    {
+        return new Response(
+            $this->post('getInventorySuppliers', $filters)
+        );
+    }
+
+    public function addInventorySupplier(array $data): Response
+    {
+        return new Response(
+            $this->post('addInventorySupplier', $data)
+        );
+    }
+
+    public function deleteInventorySupplier(int $supplierId): Response
+    {
+        return new Response(
+            $this->post('deleteInventorySupplier', [
+                'supplier_id' => $supplierId,
+            ])
+        );
+    }
+}
diff --git a/src/Baselinker.php b/src/Baselinker.php
index 7f281ae..446a400 100644
--- a/src/Baselinker.php
+++ b/src/Baselinker.php
@@ -5,7 +5,10 @@
 use Baselinker\Api\Request\BaselinkerConnect;
 use Baselinker\Api\Request\CourierShipments;
 use Baselinker\Api\Request\ExternalStorages;
+use Baselinker\Api\Request\InventoryDocuments;
 use Baselinker\Api\Request\InventoryPayers;
+use Baselinker\Api\Request\InventoryPurchaseOrders;
+use Baselinker\Api\Request\InventorySuppliers;
 use Baselinker\Api\Request\OrderReturns;
 use Baselinker\Api\Request\Orders;
 use Baselinker\Api\Request\ProductCatalog;
@@ -26,6 +29,21 @@ public function productCatalog(): ProductCatalog
         return new ProductCatalog($this->config);
     }
 
+    public function inventoryDocuments(): InventoryDocuments
+    {
+        return new InventoryDocuments($this->config);
+    }
+
+    public function inventoryPurchaseOrders(): InventoryPurchaseOrders
+    {
+        return new InventoryPurchaseOrders($this->config);
+    }
+
+    public function inventorySuppliers(): InventorySuppliers
+    {
+        return new InventorySuppliers($this->config);
+    }
+
     public function warehouseDocuments(): WarehouseDocuments
     {
         return new WarehouseDocuments($this->config);
diff --git a/tests/BaselinkerTest.php b/tests/BaselinkerTest.php
index 1fd6c21..06551d9 100644
--- a/tests/BaselinkerTest.php
+++ b/tests/BaselinkerTest.php
@@ -5,7 +5,10 @@
 use Baselinker\Api\Request\BaselinkerConnect;
 use Baselinker\Api\Request\CourierShipments;
 use Baselinker\Api\Request\ExternalStorages;
+use Baselinker\Api\Request\InventoryDocuments;
 use Baselinker\Api\Request\InventoryPayers;
+use Baselinker\Api\Request\InventoryPurchaseOrders;
+use Baselinker\Api\Request\InventorySuppliers;
 use Baselinker\Api\Request\OrderReturns;
 use Baselinker\Api\Request\Orders;
 use Baselinker\Api\Request\ProductCatalog;
@@ -43,6 +46,33 @@ public function testWarehousePurchaseOrders(): void
         $this->assertInstanceOf(WarehousePurchaseOrders::class, $warehousePurchaseOrders);
     }
 
+    public function testInventoryDocuments(): void
+    {
+        $baselinker = new Baselinker('token');
+
+        $inventoryDocuments = $baselinker->inventoryDocuments();
+
+        $this->assertInstanceOf(InventoryDocuments::class, $inventoryDocuments);
+    }
+
+    public function testInventoryPurchaseOrders(): void
+    {
+        $baselinker = new Baselinker('token');
+
+        $inventoryPurchaseOrders = $baselinker->inventoryPurchaseOrders();
+
+        $this->assertInstanceOf(InventoryPurchaseOrders::class, $inventoryPurchaseOrders);
+    }
+
+    public function testInventorySuppliers(): void
+    {
+        $baselinker = new Baselinker('token');
+
+        $inventorySuppliers = $baselinker->inventorySuppliers();
+
+        $this->assertInstanceOf(InventorySuppliers::class, $inventorySuppliers);
+    }
+
     public function testInventoryPayers(): void
     {
         $baselinker = new Baselinker('token');