Every agent framework README says "multi-agent". AutoGen, CrewAI, LangGraph, MetaGPT each have 20k+ GitHub stars, and the term "multi-agent" appears in thousands of repo descriptions. But what do projects that call themselves multi-agent actually implement? Until now, nobody measured the population — only how to build frameworks, or theory about whether multi-agent is "just prompting". A new census (86 strictly-filtered, self-described "multi-agent" repos with 1k+ stars, plus 18 seed framew...