Full protocol surface audit across Colibri's 5 current protocols
(~5,324 lines). Key finding: A2A is an interoperability play, not a
complexity reduction play.
Replaced:
- Mother MCP-over-SSH bridge → A2A HTTP endpoint (−160 lines, +380 lines)
- External MCP discovery → Agent Card (future, zero adopters today)
- Ad-hoc cost format → typed A2A part (negligible code impact)
Not replaced: Unix socket (local IPC), spawner (process lifecycle),
glasspane (PTY observer), store (SQLite), MCP editor bridge (human↔tool).
Net delta: ~0 lines (moves code, doesn't shrink it). Protocol count: 5→6.
Recommendation: A2A is Phase 3 — not Phase 2, not 0.12. The current
MCP-over-SSH bridge (437 lines) works for 4 nodes. A2A pays off at 10+
nodes or when third-party tools ship A2A support. The Agent Card design
in HIVE-PANE.md stays as a north star.
Cross-linked from hive-pane.md + wiki index. 182 refs, clean lint.
Sam & Claude
affee26afa