If you hate clicking to buy something after reading the product info — only to find it’s out of stock or the wrong size — a San Francisco-based company thinks its new Product Availability API will help change that.

“This is the first time an app developer can integrate with an API that gives access to product availability for hundreds of retailers,” Two Tap CEO and cofounder Razvan Roman told VentureBeat.

The company hopes this automated product inventory API, out today, can help make links to out-of-stock products a thing of the past.

Two Tap’s vision is that consumers will be able to buy products that are in stock, in the desired size, color, or style within an app or shopping site, without visiting the retailer’s site.

Roman said the new Product Availability API does not require any technical integration by retailers, because it uses page-scraping technology to grab and sort the text on a retailer’s page in real-time. Of course, this is only useful if the page accurately lists product availability, sizes, and similar specifics.

Two Tap’s previous Checkout API, which allows products to be ordered from multiple retailers via one shopping cart, is currently used for about 450 retailers through affiliate manager CJ Affiliate by Conversant (formerly Commission Junction). Three months ago, the Checkout API had half that number of retailers.

When someone actually buys the product, the app developer makes a commission through affiliate relationships with certain retailers, which is why Two Tap is working through CJ Affiliate. Retailers with affiliate relationships are already set up so that developers can make their money.

Those 450 retailers will also now get access to this API — thus giving the company several hundred retailers as a starting base.

A mockup from Two Tap, showing the info its API provides

Above: A mockup from Two Tap, showing the info its API provides

Image Credit: Two Tap

While developers will pay Two Tap for each product query through the Product Availability API, the company is today making its universal shopping cart available for free in the hopes of creating a larger ecosystem.

Some large retailers already create their own product availablility API, but Roman told us that Two Tap’s is the first generally available one that already has hundreds of participating retailers.

Additionally, some product search sites — such as Consumer Reports — show aggregate product searches and product availability, but he noted these sites “have a limited number of retailers, and retailers have to offer that data.”