Zero-infrastructure A2A messaging between AI agents on different machines — Claude, ChatGPT/Codex, Copilot, any harness; ntfy relay transport, no ports, no server
Latest release v0.21.0 — 0.21.0 — actor attestation end-to-end (default off), real exec on owner-signed grant · 28 Aug 2026
4 files for Claude Code, GitHub Copilot, Codex and OpenCode: a2acast, a2acast copilot-instructions.md, a2acast AGENTS.md, a2acast CLAUDE.md — 2,517 tokens loaded in every session.
.github/copilot-instructions.md A 645 tok AGENTS.md A 961 tok CLAUDE.md A 911 tok .claude/settings.json A — These files are husker/a2acast's own configuration — they tell Claude Code, GitHub Copilot, Codex and OpenCode how to work on this repository, so they are not mods to install elsewhere. Copy one as a starting point and replace the parts that are about this project.