GitHub co-founder Tom Preston-Werner. Photo credit: JD Lasica on Flickr, under Creative Commons license

Stream, a Boulder, Colorado-based chat APIs startup, has announced that it’s raised $15 million in Series A funding from investors including GitHub co-founder Tom Preston-Werner, Datadog CEO Olivier Pomel, and venture capital firms GGV Capital, Knight, Arthur Ventures, and 01 Advisors. GGV Capital led the round and is getting a board seat at Stream as a result. Tiffany Luck, a Vice President at GGV Capital, is taking the board seat. With the new funding, Stream has now raised a total of $20 million since its inception.

Initially located in Amsterdam, The Netherlands, Stream only moved to the US after getting accepted into the famed Techstars NYC startup incubator program. Currently, the company is based out of Boulder, Colorado and with 55 employees. Stream develops chat APIs used by enterprises to build chat and activity feeds for their applications.