The quest to make a large language model (LLM) a Pokémon master began last February, when an Anthropic researcher launched a livestream of Claude playing the 1996 Game Boy game Pokémon Red to accompany the release of Claude Sonnet 3.7, at the time one of the world’s best models. As the company noted, this was the first Claude model that could meaningfully play the game at all (previous models “wandered aimlessly or got stuck in loops,” and could not get past the game’s opening beats). Within the first weeks, the stream attracted approximately 2,000 viewers, cheering Claude along in the public chat.