Multi-Agent Collaboration

The protocol layer for multi-session collaboration: who talks to whom, in what shape, and how to wait without deadlocking. It runs over herdr or orca — probe the environment first, route the transport by result. Everything below was distilled from 32 real sessions; failure modes carry evidence in pitfalls.md.

Environment & routing

Probe once at session start, before any send:

if [ -n "${HERDR_PANE_ID:-}" ]; then ENV=herdr
elif [ -n "${ORCA_CLI_COMMAND:-}" ] || orca-ide status --json >/dev/null 2>&1 \
  || orca status --json >/dev/null 2>&1; then ENV=orca
else ENV=none; fi

• herdr — inline commands below are herdr-shaped; CLI syntax lives in the herdr skill.
• orca — load orca-routing.md once and follow it for the session; deep mechanics live in the installed orca-cli/orchestration skills (orca skills get <topic> --full).
• none — no multiplexer detected: fall back to pi subagents; the protocol sections below still govern how you brief and verify them.