Merge pull request #55923 from NousResearch/bb/serve-headless-no-web-build

feat(cli): make hermes serve a real headless backend (no web UI build/mount, neutral ready sentinel)

hermes_cli/main.py

@@ -11928,6 +11928,11 @@ def cmd_dashboard(args):
         remaining = _find_stale_dashboard_pids()
         sys.exit(1 if remaining else 0)
 
+    # `serve` is the headless backend: no UI build, no SPA mount, neutral
+    # ready sentinel. Resolved once and threaded through the re-exec, the
+    # build gate, and start_server.
+    _headless_backend = getattr(args, "headless_backend", False)
+
     # ── Unified profile launch routing ────────────────────────────────
     # The dashboard is a MACHINE management surface: it can read/write any
     # profile via the per-request ?profile= scoping. Running one dashboard
@@ -11973,7 +11978,9 @@ def cmd_dashboard(args):
         reexec_argv = [
             sys.executable, "-m", "hermes_cli.main",
             "-p", "default",
-            "dashboard",
+            # Preserve the lean serve path across the re-exec so a named-profile
+            # `serve` doesn't silently rebuild the UI as `dashboard`.
+            "serve" if _headless_backend else "dashboard",
             "--port", str(args.port),
             "--host", args.host,
             "--open-profile", _launch_profile,
@@ -12042,7 +12049,11 @@ def cmd_dashboard(args):
     # backend is the desktop's primary entrypoint and needs the same.
     _sync_bundled_skills_quietly()
 
-    if "HERMES_WEB_DIST" not in os.environ and not getattr(args, "skip_build", False):
+    if _headless_backend:
+        # Don't build the SPA, and tell mount_spa() (read at web_server import
+        # below) to disable it even if a stray dist exists. Set it first.
+        os.environ["HERMES_SERVE_HEADLESS"] = "1"
+    elif "HERMES_WEB_DIST" not in os.environ and not getattr(args, "skip_build", False):
         if not _build_web_ui(PROJECT_ROOT / "web", fatal=True):
             sys.exit(1)
     elif getattr(args, "skip_build", False):
@@ -12115,6 +12126,7 @@ def cmd_dashboard(args):
         open_browser=not args.no_open,
         allow_public=getattr(args, "insecure", False),
         initial_profile=getattr(args, "open_profile", "") or "",
+        headless=_headless_backend,
     )