fix(cli): auto-detect server backend + herdr reconcile fixes

src/cli_agent_orchestrator/api/main.py

@@ -378,12 +378,18 @@ def _build_pty_env() -> Dict[str, str]:
 async def health_check():
     import shutil
 
+    from cli_agent_orchestrator.backends.herdr_backend import HerdrBackend
+
     def _probe(binary: str) -> str:
         return "ok" if shutil.which(binary) else "unavailable"
 
+    backend = get_backend()
+    backend_name = "herdr" if isinstance(backend, HerdrBackend) else "tmux"
+
     return {
         "status": "ok",
         "service": "cli-agent-orchestrator",
+        "terminal_backend": backend_name,
         "components": {
             "cao": "ok",
             "herdr": _probe("herdr"),

src/cli_agent_orchestrator/backends/herdr_backend.py

@@ -109,7 +109,7 @@ def _sanitize_herdr_args(args: List[str]) -> List[str]:
 
 
 # Cache TTL for pane_id resolution (seconds).
-# Used by _resolve_pane_id() (inbox service path, herdr-native terminal_ids) and
+# Used by get_pane_id() (fast-path, reads the cache populated at create time) and
 # _resolve_workspace_id(). _resolve_pane_id_from_window() never caches pane_ids —
 # herdr renumbers panes on deletion, so it resolves the pane fresh every call.
 _PANE_CACHE_TTL = 5.0
@@ -202,42 +202,6 @@ def _parse_herdr_json(self, stdout: str) -> dict:
             return cast(dict, data["result"])
         return cast(dict, data)
 
-    def _resolve_pane_id(self, terminal_id: str) -> str:
-        """Resolve terminal_id to current compact pane_id.
-
-        Uses a cache with 5s TTL to reduce redundant herdr pane list calls.
-
-        Args:
-            terminal_id: Stable terminal identifier
-
-        Returns:
-            Current compact pane_id
-
-        Raises:
-            TerminalNotFoundError: If terminal_id not found in pane list
-        """
-        # Check cache
-        if terminal_id in self._pane_cache:
-            pane_id, cached_at = self._pane_cache[terminal_id]
-            if time.time() - cached_at < _PANE_CACHE_TTL:
-                return pane_id
-
-        # Resolve via herdr pane list
-        result = self._run_herdr(["pane", "list"])
-        try:
-            data = self._parse_herdr_json(result.stdout)
-            panes = data.get("panes", []) if isinstance(data, dict) else data
-        except json.JSONDecodeError as e:
-            raise TerminalBackendError(f"Failed to parse herdr pane list output: {e}") from e
-
-        for pane in panes:
-            if pane.get("terminal_id") == terminal_id:
-                pane_id = str(pane["pane_id"])
-                self._pane_cache[terminal_id] = (pane_id, time.time())
-                return pane_id
-
-        raise TerminalNotFoundError(terminal_id)
-
     def _resolve_workspace_id(self, session_name: str) -> str:
         """Resolve session_name (workspace label) to workspace ID.
 
@@ -887,11 +851,3 @@ def _resolve_pane_id_from_window(self, session_name: str, window_name: str) -> s
                 return str(pane["pane_id"])
 
         raise TerminalNotFoundError(f"{session_name}:{window_name}")
-
-    def invalidate_cache(self) -> None:
-        """Invalidate all cached pane_id mappings.
-
-        Called after herdr reconnection when pane_ids may have compacted.
-        """
-        self._pane_cache.clear()
-        self._workspace_cache.clear()

src/cli_agent_orchestrator/cli/commands/info.py

@@ -1,5 +1,6 @@
 """Info command for CLI Agent Orchestrator CLI."""
 
+import os
 import subprocess
 
 import click
@@ -20,18 +21,22 @@ def info():
         # Display database path
         click.echo(f"Database path: {DATABASE_FILE}")
 
-        # Try to get current session name from tmux
-        session_name = None
-        try:
-            result = subprocess.run(
-                ["tmux", "display-message", "-p", "#S"],
-                capture_output=True,
-                text=True,
-                check=True,
-            )
-            session_name = result.stdout.strip()
-        except (subprocess.CalledProcessError, FileNotFoundError):
-            pass
+        # Try to get current session name:
+        # 1. Check CAO_SESSION_NAME env var (set by herdr backend)
+        # 2. Fall back to tmux display-message (works for tmux backend)
+        session_name = os.environ.get("CAO_SESSION_NAME")
+
+        if not session_name:
+            try:
+                result = subprocess.run(
+                    ["tmux", "display-message", "-p", "#S"],
+                    capture_output=True,
+                    text=True,
+                    check=True,
+                )
+                session_name = result.stdout.strip()
+            except (subprocess.CalledProcessError, FileNotFoundError):
+                pass
 
         if session_name and session_name.startswith(SESSION_PREFIX):
             try:

src/cli_agent_orchestrator/cli/commands/launch.py

@@ -16,7 +16,11 @@
     SERVER_PORT,
 )
 from cli_agent_orchestrator.models.terminal import TerminalStatus
-from cli_agent_orchestrator.utils.terminal import poll_until_done, wait_until_terminal_status
+from cli_agent_orchestrator.utils.terminal import (
+    poll_until_done,
+    sync_backend_from_server,
+    wait_until_terminal_status,
+)
 
 # Providers that require workspace folder access
 PROVIDERS_REQUIRING_WORKSPACE_ACCESS = {
@@ -302,6 +306,10 @@ def launch(
         # if it times out we still attach so the user can inspect the
         # half-initialized session rather than orphan it in tmux.
         if not headless:
+            # Align the CLI's backend singleton with the running server.
+            # Without this, ``cao-server --terminal herdr`` + no config.json
+            # entry causes the CLI to default to tmux. See issue #308.
+            sync_backend_from_server()
             ready = wait_until_terminal_status(
                 terminal["id"],
                 {TerminalStatus.IDLE, TerminalStatus.COMPLETED},

src/cli_agent_orchestrator/cli/commands/terminal.py

@@ -8,6 +8,7 @@
 
 from cli_agent_orchestrator.backends.registry import get_backend
 from cli_agent_orchestrator.constants import API_BASE_URL, TERMINAL_LOG_DIR
+from cli_agent_orchestrator.utils.terminal import sync_backend_from_server
 
 
 @click.group()
@@ -62,6 +63,7 @@ def restore(terminal_id: str):
         window_shell = f"exec {login_shell} -l"
 
     try:
+        sync_backend_from_server()
         get_backend().create_window(
             session_name,
             window_name,