This article focuses on Chosŏn's informal diplomacy with the Qing dynasty that guided Chosŏn Korea's diplomatic engagement with Japan in the 1870s. The Chosŏn–Qing literary correspondence in Kang Wi's (姜瑋, 1820–1884) brush talk records has been viewed as historical evidence of Chosŏn's intelligence-gathering activities which formed the basis of a new diplomatic enterprise for dealing with modern imperial powers. What has received less attention, however, is the implementation and implications of the informal diplomacy reflected in Kang's diplomatic activities and his discursive practice. Based on a personal and unofficial account by an intellectual on the margins of the established social and international order, this study revisits the political and intelligence-gathering processes that led up to the 1876 peace agreement, which was the culmination of the Qing and Chosŏn dynasties’ concerted efforts as they transitioned to a changing world order in East Asia. In addition, this article further illuminates Kang's agency, despite his secondary social status, in Chosŏn's changing attitude towards Westerners and Westernized Japan. I argue that as both interviewer and transcriber, and from his position on the periphery of the Confucian ruling elites in the late Chosŏn period, Kang provided a new framework through which to formulate policies by reconfiguring his brush talk records to implement his own agenda as a member of the chungin (middle people) literary elite.