feat: add shell-native message routing

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a03397-4d51-7fd1-8ff2-946eb22ea2bc

src/tamq/tmux.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import os
+import re
 import shlex
 import shutil
 from uuid import uuid4
@@ -9,6 +10,7 @@ from collections.abc import Sequence
 from dataclasses import dataclass
 from pathlib import Path
 
+from .config import state_dir
 from .registry import repository_paths, validate_targets
 
 
@@ -48,11 +50,65 @@ class TmuxManager:
         *,
         tmux_command: Sequence[str] | None = None,
         tamq_command: Sequence[str] | None = None,
+        command_dir: Path | None = None,
     ):
         self.session = session
         socket_name = os.environ.get("TAMQ_TMUX_SOCKET")
         self.tmux_command = tuple(tmux_command or (["tmux", "-L", socket_name] if socket_name else ["tmux"]))
-        self.tamq_command = tuple(tamq_command or ["tamq"])
+        if tamq_command is None:
+            self.tamq_command = (shutil.which("tamq") or "tamq",)
+        else:
+            self.tamq_command = tuple(tamq_command)
+        configured_command_dir = os.environ.get("TAMQ_COMMAND_DIR")
+        if command_dir is not None:
+            self.command_dir = command_dir
+        elif configured_command_dir:
+            self.command_dir = Path(configured_command_dir)
+        elif (
+            len(self.tamq_command) == 1
+            and Path(self.tamq_command[0]).is_absolute()
+            and os.access(Path(self.tamq_command[0]).parent, os.W_OK | os.X_OK)
+        ):
+            self.command_dir = Path(self.tamq_command[0]).parent
+        else:
+            self.command_dir = state_dir() / "commands" / session
+
+    def _install_address_commands(self, repos: Sequence[str]) -> None:
+        """Install tamq-owned commands without modifying a user's shell files."""
+        self.command_dir.mkdir(parents=True, exist_ok=True, mode=0o700)
+        if not os.access(self.command_dir, os.W_OK | os.X_OK):
+            raise TmuxError(f"address command directory is not writable: {self.command_dir}")
+        for repo in repos:
+            if re.fullmatch(r"[A-Za-z0-9][A-Za-z0-9._-]*", repo) is None:
+                raise TmuxError(
+                    f"repository name cannot be exposed as a shell command: {repo!r}"
+                )
+            target = f"@{repo}:"
+            script = (
+                "#!/bin/sh\n"
+                "# tamq-address-command v1\n"
+                f"exec {shell_join(list(self.tamq_command))} send -- {shlex.quote(target)} \"$@\"\n"
+            )
+            for name in (f"@{repo}", target):
+                destination = self.command_dir / name
+                if destination.exists() or destination.is_symlink():
+                    if destination.is_symlink() or not destination.is_file():
+                        raise TmuxError(f"refusing to replace existing command: {destination}")
+                    try:
+                        existing = destination.read_text(encoding="utf-8")
+                    except OSError as exc:
+                        raise TmuxError(f"cannot inspect existing command: {destination}") from exc
+                    if "# tamq-address-command v1" not in existing:
+                        raise TmuxError(f"refusing to replace existing command: {destination}")
+                temporary = self.command_dir / f".{name}.{uuid4().hex}.tmp"
+                temporary.write_text(script, encoding="utf-8")
+                temporary.chmod(0o700)
+                temporary.replace(destination)
+
+    def _window_environment(self, repo: str) -> tuple[str, ...]:
+        path = os.environ.get("PATH", "")
+        command_path = f"{self.command_dir}{os.pathsep}{path}" if path else str(self.command_dir)
+        return "-e", f"TAMQ_REPO={repo}", "-e", f"PATH={command_path}"
 
     def _run(self, *args: str, check: bool = True) -> str:
         result = subprocess.run([*self.tmux_command, *args], text=True, capture_output=True, check=False)
@@ -133,7 +189,7 @@ class TmuxManager:
                 first_repo = plan.repos[0]
                 self._run(
                     "new-session", "-d", "-s", self.session, "-n", "__tamq_boot",
-                    "-e", f"TAMQ_REPO={first_repo}",
+                    *self._window_environment(first_repo),
                     "-c", plan.paths[first_repo],
                 )
                 created_session = True
@@ -151,6 +207,12 @@ class TmuxManager:
                 self._run("set-option", "-t", self.session, "@tamq_instance_id", instance_id)
             self._run("set-option", "-t", self.session, "@tamq_managed", "1")
             windows = self._run("list-windows", "-t", self.session, "-F", "#{window_name}").splitlines()
+            addressable_repos = [repo for repo in windows if repo != "__tamq_boot"]
+            addressable_repos.extend(repo for repo in plan.repos if repo not in addressable_repos)
+            self._install_address_commands(addressable_repos)
+            command_path = self._window_environment(plan.repos[0])[-1].removeprefix("PATH=")
+            self._run("set-environment", "-t", self.session, "PATH", command_path)
+            self._run("set-option", "-t", self.session, "@tamq_command_dir", str(self.command_dir))
             for index, repo in enumerate(plan.repos):
                 if repo in windows:
                     continue
@@ -162,7 +224,7 @@ class TmuxManager:
                 else:
                     self._run(
                         "new-window", "-d", "-t", self.session, "-n", repo,
-                        "-e", f"TAMQ_REPO={repo}", "-c", plan.paths[repo],
+                        *self._window_environment(repo), "-c", plan.paths[repo],
                     )
                     windows.append(repo)
                 created_windows.append(repo)