To prevent abuse and unwanted usage of Buildify database, Buildify offers realtors different product bundles to choose from. To make an api call, you need to subscribe to a Buildify product.
Once you are subscribed to a product, you can get started calling Buildify api endpoints
For an example, you have subscribed to one of the product of Buildify with id "u9u9naph31w8uvfk", you can call search listings with https://api.getbuildify.com/u9u9naph31w8uvfk/searchListings