Square Wednesday announced the availabilty of two APIs as part of a "Build with Square" program that enables merchants and software developers to add payment acceptance options either at the register or online, according to a company blog post.

Square's Register API enables any iOS point of sale to be customized to process payments with Square, according to the announcement.

"We know that some sellers — especially in retail, like bike shops or wineries — have highly individualized point-of-sale needs," Square wrote in the post. "By integrating with Square, sellers with a third-party point of sale will be able to use our beautiful and affordable hardware, accept EMV payments and Apple Pay, and receive the same fair and transparent pricing and financial services available to all our sellers."

Square also introduced what it described as an e-commerce API that lets sellers use Square to process online payments on their own self-hosted, fully developed website.