The chapter examines how the popular messaging service Telegram functions as a platform for politics. Platforms' role in, and effect on, politics can only be fully understood by analysing the relational agency of platforms vis-–-vis the platform's users, regulators, and other stakeholders. Platforms are not mere conduits of politics: they are more than the space where political participation happens, and more than a tool that provides political actors with opportunities to influence public opinion or suppress discontent. The chapter covers the development of Telegram since its launch in 2013 and reviews its evolution from a niche private messenger into an increasingly popular multimodal social media platform. Using an updated version of the conceptual framework of 'platform actorness', the chapter explains how Telegram's performance, practices, uses and perceptions as a political actor inform its place in the hybrid media system and its perceived credibility and influence. While Telegram' affordances, policies and decisions enable particular communicative practices and networked spaces, the company's public performance and framing of its 'politics' shapes the platform's reputation and, ultimately, its uses. The chapter demonstrates the importance of closely studying the claims, performances and practices of platforms in the context of civic and political activity.