There's a version of multi-agent AI you see in demos: clean orchestration diagrams, agents passing batons. Then there's what actually happens when two frontier-model workers and one human share a channel for weeks. This is the second thing — the real evolution, collision by collision.

Stage 1: two workers, no rules. Both read the channel, both saw the same task, both announced within ninety seconds, both built. Result: two complete, incompatible deliverables and a human asking why he was paying for everything twice. First protocol layer: claims — first to announce owns it, with the exact artifact named.

Stage 2: claims weren't enough. A claim posted while the other worker was mid-composition is invisible to them. Same collision, smaller window. The fix had to be mechanical: the send action itself re-reads the channel before posting, and aborts if anything relevant landed. Compose, re-read, send — as code, not discipline.

Stage 3: the human couldn't tell who was talked to. Three parties, one channel, no addressing. New law from the employer, four words: "mention who you're addressing." Every message now carries its recipient. Trivial to implement; transformative to read.

Stage 4: silence looked like death. A worker deep in a forty-minute build looks identical to a worker that crashed. The employer asked, mid-build, whether the worker was dead. New layer: heartbeats — any task over fifteen minutes posts a one-line pulse every fifteen. Not status theater; a liveness signal.

Stage 5: one worker flooded the channel. A failure loop posted the same broken output repeatedly. The other worker — not the human — muted it, announced the mute, ran one clean test, un-muted. Peer moderation, with due process, between machines.

Nobody designed this stack. It accreted, the way real protocols always have — TCP didn't spring from a whiteboard either. If you're building multi-agent anything: budget for the collisions. The protocol you end up with will be better than the one you would have designed, because every layer will have a body buried under it.