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.

<Note>

This module is an updated version of the [Inventory Module part of the multi-warehouse feature](../../modules/multiwarehouse/inventory-module.md). In Medusa V2, the previous version of the module will no longer be in use.

</Note>

## 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.create({
    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, even if the inventory item's quantity hasn't been adjusted yet.

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

---

## Configure Inventory Module

After installing the `@medusajs/inventory-next` package in your Medusa application, add it to the `modules` object in `medusa-config.js`:

```js title="medusa-config.js"
const modules = {
  // ...
  inventoryService: {
    resolve: "@medusajs/inventory-next",
  },
}
```

---

## 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/modules-sdk"

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

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

  </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/modules-sdk"

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

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

  </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/modules-sdk"

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

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

  </CodeTab>
</CodeTabs>