> For the complete documentation index, see [llms.txt](https://developer.esw.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.esw.com/inventory/inventory-api/concepts/available-to-sell-ats.md).

# Available-to-Sell (ATS)

What Available-to-Sell (ATS) means, which inventory controls affect it, and how it differs from physical On Hand stock.

Available-to-Sell (ATS) represents inventory currently available for new demand after applicable inventory controls and existing commitments have been considered. ATS may differ from physical stock held within the fulfillment network.

Both Inventory API endpoints return ATS, not simply physical On Hand inventory.

## What can affect ATS

Depending on retailer configuration, ATS can be affected by:

* Inventory reservations
* Inventory already allocated to orders
* Safety Stock
* No Stock Overrides
* Other applicable inventory controls

## ATS compared with On Hand

| Measure | What it represents                                                                   | Returned by the Inventory API |
| ------- | ------------------------------------------------------------------------------------ | ----------------------------- |
| ATS     | Inventory available for new demand after inventory controls and existing commitments | Yes                           |
| On Hand | Physical stock held within the fulfillment network                                   | No                            |

## Quantity rules

* `quantity` is an integer.
* It is always zero or greater and is never negative.
* When a delivery country is supplied, it is aggregated across the fulfillment centres applicable to that country. See [Delivery-Country Availability](/inventory/inventory-api/concepts/delivery-country-availability.md).

{% hint style="danger" %}
A failed API request must not be interpreted as zero inventory. Treat a quantity of `0` as a valid zero-ATS position only when it is returned in a successful response.
{% endhint %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://developer.esw.com/inventory/inventory-api/concepts/available-to-sell-ats.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.