import { CodeTabs, CodeTab } from "docs-ui"

export const metadata = {
  title: `Inventory Module`,
}

# {metadata.title}

The Inventory Module is the `@medusajs/inventory-next` NPM package that provides inventory-related features in your Medusa and Node.js applications.

## Features

### Inventory Items Management

Store and manage inventory of any stock-kept item, such as product variants.

Inventory items hold details of the underlying stock-kept item, as well as inventory details such as whether the item requires shipping.

```ts
const inventoryItem = await inventoryModuleService.createInventoryItems({
  sku: "SHIRT",
  title: "Green Medusa Shirt",
  requires_shipping: true,
})
```

### Inventory Across Locations

Inventory items' quantities are set per locations through inventory levels. This gives you more flexibility in managing the quantity of a stock-kept item across different locations, such as different warehouses.

```ts
const inventoryLevel = await inventoryModuleService.createInventoryLevels([
  {
    inventory_item_id: "iitem_123",
    location_id: "sloc_123",
    stocked_quantity: 20,
  },
])
```

### Reservation Management

Reserve quantities of inventory items at specific locations for orders or other purposes. The reserved quantity isn't considered for purchase, but can be deleted to revert the reservation.

```ts
const reservationItem = await inventoryModuleService.createReservationItems([
  {
    inventory_item_id: "iitem_123",
    location_id: "sloc_123",
    quantity: 10,
  },
])
```

### Check Inventory Availability

Check whether an inventory item has the necessary quantity for purchase. Any reserved quantity is considered unavailable.

```ts
const isAvailable = await inventoryModuleService.confirmInventory(
  inventoryItemId,
  [locationId],
  neededQuantity
)
```

---

## How to Use Inventory Module's Service

You can use the Inventory Module's main service by resolving from the Medusa container the resource `ModuleRegistrationName.INVENTORY` imported from `@medusajs/modules-sdk`.

For example:

<CodeTabs groupId="resource-type">
  <CodeTab label="API Route" value="api-route">

  ```ts title="src/api/store/custom/route.ts"
  import { MedusaRequest, MedusaResponse } from "@medusajs/medusa"
  import { IInventoryService } from "@medusajs/types"
  import { ModuleRegistrationName } from "@medusajs/utils"

export async function GET(
  request: MedusaRequest,
  res: MedusaResponse
): Promise<void> {
  const inventoryModuleService: IInventoryService = request.scope.resolve(
    ModuleRegistrationName.INVENTORY
  )

  res.json({
    inventory_items: await inventoryModuleService.listInventoryItems({}),
  })
}
```

  </CodeTab>
  <CodeTab label="Subscriber" value="subscribers">

  ```ts title="src/subscribers/custom-handler.ts"
  import { SubscriberArgs } from "@medusajs/medusa"
  import { IInventoryService } from "@medusajs/types"
  import { ModuleRegistrationName } from "@medusajs/utils"

export default async function subscriberHandler({ container }: SubscriberArgs) {
  const inventoryModuleService: IInventoryService = container.resolve(
    ModuleRegistrationName.INVENTORY
  )

  const inventoryItems = await inventoryModuleService.listInventoryItems({})
}
```

  </CodeTab>
  <CodeTab label="Workflow Step" value="workflow-step">

  ```ts title="src/workflows/hello-world/step1.ts"
  import { createStep } from "@medusajs/workflows-sdk"
  import { IInventoryService } from "@medusajs/types"
  import { ModuleRegistrationName } from "@medusajs/utils"

const step1 = createStep("step-1", async (_, { container }) => {
  const inventoryModuleService: IInventoryService = container.resolve(
    ModuleRegistrationName.INVENTORY
  )

  const inventoryItems = await inventoryModuleService.listInventoryItems({})
})
```

  </CodeTab>
</CodeTabs>