It's legal to use but not sell and distribute and they don't have dispensaries. Also zoning is an issue because landwise, DC is tiny. Concerns of a coffeeshop being next to a school, church etc. Smokers go black market or make "donations" at 420 eventbrite pop-up parties and connect with delivery men with a minimum $50 donation. Or you can join "art clubs" (smoke and paint sessions) and "audio sessions" (toke and listening parties) with membership fees like a meet and greet. Police have recently caught onto this so they aren't advertised as much on eventbrite, more personal websites.
If you live in the surrounding VA/MD suburbs, you have to meet the delivery person right inside the border - mainly for Marylanders (Most reputable liveries will not cross the Anacostia into SouthEast DC). Exceptions for Arlington/Alexandria and even Reston and Loudoun Co. since clients are wealthy, professional, not ratchet and less likely to make things hot. So technically it's legal but it's not.
Just make sure to state donation else the vendor will hit you with the 
Wow!!! Tell'em why you mad son.
