This article develops the concept of ‘frontline diplomacy’ – what practitioners referring to work in embassies, consulates, and permanent representation as ‘the field’ –, defined here as all diplomats’ activities taking place away from headquarters. IR scholarship tends to focus on Ministries of Foreign Affairs located in capitals. On the contrary, building on the practice turn in IR, we first show that international politics emerge from frontline practices. Adding to criticism against the practice turn, we then explain that it has missed important transformations occurring in frontline diplomacy because it tends to privilege stability over change. We finally discuss two innovations in frontline practices: the action of Sherpas in G20 summits following the 2008 crisis and the use of Twitter by US Ambassador to Russia Michael McFaul (2012–14). For each we answer three questions: How do these activities transform traditional modes of operation? How are non-state actors involved in them? What do they tell about transformation of global politics? Because diplomatic practices at the frontlines epitomise international politics, these new directions for inquiry contribute substantively to IR scholarship. At the theoretical level, they enrich the continuing encounter between IR and diplomatic studies through practice theory and help to understand change in practice.