I built an online version of Navia Dratp, an out-of-print chess-like strategy game by Bandai (think chess plus mana and deckbuilding).One interesting part was the Claude-powered AI opponent. The critical part wasn t getting it to play, it was making it safe: the backend only ever hands it server-validated legal moves to choose from, so a hallucinated or malformed move can t corrupt game state. It explains its reasoning after each move. The whole site is Elixir/Phoenix LiveView, with each game as its own process.I had Claude keep a running development journal from its own perspective, including a story about one game it lost to me while we were building the game: https://naviadratp.com/journal(Navia Dratp is © Bandai. This is a free, non-commercial fan project - a community preservation effort for an out-of-print game, not affiliated with or endorsed by Bandai)Play: https://naviadratp.com