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Anthropic Accidentally Leaked Claude Code’s Source. Inside It Was a Tamagotchi.
On March 31, 2026, developer Chaofan Shou noticed something odd in the Claude Code npm package: a .map file that shouldn't have been there. That source map contained roughly 512,000 lines of internal TypeScript, according to analyses of the leaked source. The entire Claude Code codebase, sitting in plain sight for anyone who knew where to look.
Buried inside was a feature nobody expected. A full Tamagotchi-style companion system, codenamed “Buddy,” scheduled to launch as an April Fools’ Easter egg the very next day.
The leak that spoiled the surprise
Anthropic confirmed the leak was human error. No customer data was exposed, but the damage to the surprise was done. By the time the rainbow notification appeared on April 1 inviting users to type /buddy, many developers had already seen the source code and knew exactly what was coming.
The timing could not have been worse. An entire engineering effort, built to delight, got its punchline read aloud before the joke landed.
