Overview of the concepts related to inventory management.
Inventory tracks sellable stock per SKU across supply locations. It enables you to manage stock levels, enforce purchase limits, and reserve stock to ensure availability during the checkout process.
General concepts
Inventory modes
The inventory mode defines how stock is managed when Line Items are added to a Cart. The following table summarizes the available inventory modes:
| Inventory Mode | Description | Use Cases |
|---|---|---|
| None | The default inventory mode. Stock levels are not checked or updated when Line Items are added to the Cart. | - Products that are always in stock (for example: digital goods). - Businesses that do not require inventory management. - Businesses that manage their inventory externally. |
| Track only | Stock levels are checked when Line Items are added to the Cart, but stock is only updated when the Order is created. Allows Orders to be placed even if the required stock is not available at that moment. | - Products with high stock levels where reservations are unnecessary. - Businesses that want to monitor stock without reserving it. - Allows for overselling scenarios and accepting backorders. |
| Reserve on order | Stock levels are checked when Line Items are added to the Cart, but stock is only reserved and updated when the Order is created. Prevents Orders from being placed if the required stock is not available at that moment. | - Standard inventory management where stock is only deducted upon Order creation. - Businesses that want to avoid holding stock before the order is finalized. |
| Reserve on cart | Stock levels are checked and reserved when Line Items are added to the Cart. Reservations expire after a set time. | - High-demand products where stock needs to be secured during checkout. - Businesses that want to minimize the risk of stockouts during checkout. |
Inventory modes can be set at the Cart level and/or individually for each Line Item. The Line Item's inventory mode takes precedence over the Cart's mode.
Manage inventory with InventoryEntry
An InventoryEntry represents stock for a single SKU in an optional supply Channel. Only one InventoryEntry exists for each SKU and supply Channel pair. For how quickly changes to stock become visible in the API, see Inventory APIs overview.
Quantity limits
To restrict the quantity of a SKU that can be added to a Cart, you can set minimum and maximum limits on its inventory entry. For the fields that hold these limits, see Inventory APIs overview.
These limits are enforced when you create or update a Cart, and the Line Item's SKU and supply channel match the Inventory Entry.
The following applies:
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Quantity limits are independent of the inventory mode: the minimum and maximum quantity limits are enforced regardless of which inventory mode is used (None, Track only, Reserve on order, or Reserve on cart). The inventory mode controls when and how stock is reserved or updated, but does not affect quantity limit enforcement.
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Each Line Item is evaluated independently: each Line Item that matches an InventoryEntry record is evaluated independently against that InventoryEntry's defined quantity limits, regardless of whether other Line Items in the Cart use the same SKU, Product Variant, or supply Channel. This applies both when you have multiple Line Items for the same SKU and supply Channel (for example, distinguished by Custom Fields) and when you have Line Items for the same SKU across different supply Channels, allowing you to enforce distinct quantity constraints per Line Item context.
When you introduce or change limits, it can potentially affect Line Items that are already present in Carts. For more information, see the Set Inventory Limits update action documentation.
Enforcement scenarios
The following table details when quantity limits are enforced:
| Scenario | Enforcement | Notes |
|---|---|---|
| Cart creation | Yes | If any Line Item exceeds its quantity limits, the Cart creation fails. |
| Cart update | Yes | If any Cart update action results in a Line Item violating quantity limits, the entire request fails. |
| Order creation from Cart | Yes | Quantity limits are enforced when creating an Order from a Cart. If any Line Item in the Cart violates the current limits (for example, after limits change or for Frozen Carts), the order creation fails. |
| Order Edits | No | Quantity limits are not enforced during order edits. |
| Order Imports | No | Quantity limits are not enforced during order imports. |
For how to check quantity limits in your application with the API, see Inventory APIs overview.
Stock level notifications
To stay informed about inventory changes, you can set up stock level notifications. These notifications alert you when the stock quantity of an inventory entry falls below or rises above certain stock level thresholds. For how to configure the thresholds with the API, see Inventory APIs overview.
| Threshold | Purpose | Typical use cases | Message sent |
|---|---|---|---|
| Reorder point | Early-warning threshold indicating stock is low and should be replenished before running out during lead time. | - Trigger notifications or automations (ERP/OMS) to create purchase orders. - Show "low stock" messaging on the storefront. - Highlight low stock levels in internal dashboards. | InventoryEntryReorderPoint |
| Safety stock | Critical minimum threshold showing that inventory has reached an urgent, buffer-level quantity. | - Signal a critical low-stock situation. - Allow OMS/ERP to limit or stop selling. - Display "very low stock" or hide items on certain sales channels. | InventoryEntrySafetyStock |
Supply channels versus distribution channels
Supply channels (where stock is held) are distinct from distribution channels (used for price selection). For how an inventory entry references its supply channel in the API, see Inventory APIs overview. A Cart bound to a Store filters available stock and prices using the Store's configured channels.
To fulfill a single SKU from multiple inventory locations, you can add multiple Line Items to the Cart, each specifying a different supply channel.
Reservations
A Reservation temporarily holds stock for an individual Line Item in a Cart. For when the platform creates Reservations and how to configure them with the API, see Inventory APIs overview.
When a reservation is created, the available quantity of the corresponding inventory entry is decreased by the reserved amount. When a reservation expires, or is released, the available quantity is increased accordingly. Deleting a Cart also removes all associated reservations and releases the reserved quantity back to the corresponding InventoryEntries.
Reservations apply to both regular Line Items and Gift Line Items. Gift Line Items follow the same reservation behavior as regular Line Items. For how to work with Inventory through the APIs, see Inventory APIs overview.