永楽大典
In 1396, Chen was sent on a diplomatic mission to the western region of Qaidam to establish border defence. In 1397, he was sent by the Yongle Emperor as an envoy to Vietnam. From 1406 to 1411, he served in the Wenyuange (文渊阁), the imperial library in the Forbidden City, as an editor of the "Yongle Encyclopedia".