Full-stack payments platform Braintree is about to ink a big deal at 123 Townsend across from AT&T Park. (One way to retain talent is to offer a chance to see Tim Lincecum every day.)

The eBay subsidiary has an LOI to lease the entire 138k SF building, sources tell us. Right now the company sits just a few blocks away in 5,833 SF at China Basin's 185 Berry at the gateway to Mission Bay. The company has been on a fast track since it was founded in 2007 to help online and mobile businesses around the globe accept credit card payments. In 2012, it scooped up NY-based peer-to-peer payments provider Venmo and joined the PayPal family last year. (In short, this company knows everything you bought online... everything.)

More than 180 Braintree employees are spread across five offices in Chicago, San Francisco, New York, London, and Sydney, according to its website. The fully renovated brick and timber building at 123 Townsend is a vast contrast from modernized China Basin (below), made up of the six-story Wharfside Building and five-story Berry Building, connected by a landscaped, open-air courtyard. Above, McCarthy Cook VP of leasing Richard Hayes said his China Basin complex was 98% leased during an October Bisnow event.

The 123 Townsend building, long owned by Somera Capital Management, is a short walk from Caltrain. It's unclear if Braintree will be completely vacating its current space at China Basin, but some of the site's existing tenants have plans to shuffle around soon. Dropbox decided to expand by 100k SF at its current home in the Wharfside Building; when UCSF vacates a floor in 2015, Dropbox will swoop in.