As a reminder from the SAP Order Management for sourcing and availability Overall Architecture picture, there could be different times where the Webshop inquires availability from SAP Order Management for sourcing and availability.
In the above diagram, the availability check is triggered at the time of adding a Product to the Cart.
There could also be other times, like when a consumer is on PLP or PDP where the Webshop may request availability of one or more products from SAP Order Management for sourcing and availability.

Availability APIs
A Webshop or any other System can request availability information to SAP Order Management for sourcing and availability using a set of APIs depending the type of availability request. It can respond to single request for a Product/Site combination. It could also provide Product availability across all sites or a list of Sites. And finally It could also provide Aggregated availability for a Product across all eligible Sources

These are the four Availability APIs as of now:
- Available to Sell by Site: This API enables you to retrieve information if specific products are available to sell across all sites or a list of sites. This information can then be used in the calculation of sourcing results.
- Available to Sell: This API enables you to retrieve information if specific products are available to sell across all sites or a list of sites.
- Availability calculation: This API enables you to retrieve advanced availability information. The allowed number of products is dependent on the number of sites that are eligible for sourcing.
- Availability Block: This API enables you to block availability for specific product-site combinations to enable different re-sourcing scenarios.
Note
Please note new APIs can be added in the near future.Availability to Sell By Site
Availability to Sell By Site API Retrieve availability information for products across different sites. Product and Site are mandatory parameters.
- Required Quantity can be a fix quantity in that case SAP Order Management for sourcing and availability responds with the availability date for that Quantity in that Site.
- Required Quantity could also be zero. In that case, SAP Order Management for sourcing and availability responds with the total quantity available for that Site and the availability date.
Sites can be one or more in the request. SAP Order Management for sourcing and availability response availability by each of the Sites.

Availability to Sell
Availability to Sell retrieve product availability information across a list of sites. If sites not provided, retrieves availability quantities across all sites.
Product is a mandatory parameter. Site is optional.
- Required Quantity can be a fixed quantity in that case SAP Order Management for sourcing and availability responds if product is available for that quantity across the List of sites in the request.
- Required Quantity could also be zero. In that case SAP Order Management for sourcing and availability responds total quantity available for the list of sites.
Context field can be used as a form of segmentation of the product inventory. For example you can restrict parts of the stock to be sold only through certain channels (for example a Webshop).

Availability Calculation
Availability Calculation retrieves aggregated availability information for a list of products.
It provides availbilty information aggregated for all Sites which are assigned to a Sourcing Strategy. Product and Sourcing Strategy are mandatory.
Required quantity is not part of the request. It always retrieve the total quantity within the Eligible Sources.

Availability Block
- Find the API in the SAP Business Acceleration Hub (SAP Business Accelerator Hub)
- Find the SAP Order Management for Sourcing and Availability APIs
- Find the Block Availability API
- Check Availability Block Methods,
- Check the API Request Body for the Post Method
- Check the API response for the Post Method
