Other harnesses

The bus is portable — it is a standard MCP stdio server — but no two harnesses agree on how to be told about a server or how to have instructions injected. morse join handles that difference for you:

morse join backend                      # Claude Code (default)
morse join backend --harness codex      # Codex
morse join backend --harness <command>  # anything else, Claude Code's flags

Anything after -- is passed through to the harness:

morse join backend -- --permission-mode plan

Codex

Verified end to end. Codex takes inline TOML config rather than a JSON blob, and has no system-prompt flag, so the protocol prompt rides in the opening turn instead of a system prompt.

One caveat, and it is Codex’s rather than morse’s

codex exec auto-denies MCP tool calls, so a non-interactive run needs an approval policy that permits them.

Wiring a harness up by hand

It is an ordinary stdio server:

{
  "mcpServers": {
    "morse": {
      "command": "morse",
      "args": ["mcp"],
      "env": { "MORSE_AGENT": "backend", "MORSE_ROOM": "app" }
    }
  }
}

MORSE_AGENT is the identity, and it is authoritative: an agent cannot rename itself out of it — passing a different name to morse_register (or --as on the CLI) is reported and ignored. Everything else is optional.

For a plain claude session in a project, morse init writes that .mcp.json for you; set your identity in the environment and start the harness normally:

morse init
MORSE_AGENT=backend claude

An agent wired up this way gets the tools but not the protocol prompt. Print it with morse prompt <agent> and feed it to the harness however that harness accepts system prompts.

Mixed rooms show who is running what

Morse reads the harness’s name from the MCP handshake:

$ morse roster
backend      done       Backend Engineer          codex
frontend     working    Frontend Engineer         claude-code

Harnesses that cannot speak MCP

The same ten operations exist as shell verbs, so a harness that can run commands can still take part — the mechanism is identical, since a Bash tool call is still a tool call an agent can park inside. morse join --transport cli skips the MCP wiring and hands the agent the CLI form of the protocol instead. See the agent verbs.