fix(cli): derive top-level value flags from parser

(cherry picked from commit f2e5a1388115615fafde49a5f2144e5855a81d89)

hermes_cli/_parser.py

@@ -11,6 +11,7 @@ because its dispatch is tightly coupled to module-level ``cmd_*`` functions.
 """
 
 import argparse
+from functools import lru_cache
 
 
 # `--profile` / `-p` is consumed by ``main._apply_profile_override`` before
@@ -23,6 +24,20 @@ PRE_ARGPARSE_INHERITED_FLAGS: list[tuple[str, bool]] = [
 ]
 
 
+@lru_cache(maxsize=1)
+def top_level_value_flag_sets() -> tuple[frozenset[str], frozenset[str]]:
+    """Return required- and optional-value flags from the live parser."""
+    parser = build_top_level_parser()[0]
+    required: set[str] = set()
+    optional: set[str] = set()
+    for action in parser._actions:
+        if not action.option_strings or action.nargs == 0:
+            continue
+        target = optional if action.nargs == "?" else required
+        target.update(action.option_strings)
+    return frozenset(required), frozenset(optional)
+
+
 def _inherited_flag(parser, *args, **kwargs):
     """Register a flag that ``hermes_cli.relaunch`` should carry over when
     the CLI re-execs itself (e.g. after ``sessions browse`` picks a session,

hermes_cli/main.py

@@ -572,17 +572,9 @@ def _apply_profile_override() -> None:
     # 1. Check for explicit -p / --profile flag. Historically this worked even
     # after the subcommand (`hermes chat -p coder`), so keep scanning broadly.
     # The exception is command-argv passthrough regions such as `mcp add --args`.
-    value_flags = {
-        "-z", "--oneshot",
-        "-m", "--model",
-        "--provider",
-        "-t", "--toolsets",
-        "-r", "--resume",
-        "-s", "--skills",
-        "--usage-file",
-        "--in",
-    }
-    optional_value_flags = {"-c", "--continue"}
+    from hermes_cli._parser import top_level_value_flag_sets
+
+    value_flags, optional_value_flags = top_level_value_flag_sets()
     i = 0
     while i < len(argv):
         arg = argv[i]
@@ -11908,33 +11900,6 @@ _BUILTIN_SUBCOMMANDS = frozenset(
 )
 
 
-# Top-level flags that take a value. Needed by ``_first_positional_argv``
-# so that in ``hermes -m gpt5 chat``, ``gpt5`` is correctly skipped as a
-# flag value rather than misclassified as a subcommand. Kept in sync with
-# the top-level flags declared in ``hermes_cli/_parser.py``.
-#
-# Correctness-safe either way: missing an entry here only makes the
-# fast-path bail out too eagerly (we run plugin discovery when we didn't
-# need to); extra entries would make us skip a real positional.
-_TOP_LEVEL_VALUE_FLAGS = frozenset(
-    {
-        "-z", "--oneshot",
-        "-m", "--model",
-        "--provider",
-        "-t", "--toolsets",
-        "-r", "--resume",
-        "-s", "--skills",
-        "--usage-file",
-        "--in",
-        # ``-c / --continue`` is nargs='?' (optional value). Treat it as
-        # value-taking: if the next token is a subcommand-looking word
-        # the user almost certainly meant it as the session name, and
-        # either interpretation keeps us on the safe side.
-        "-c", "--continue",
-    }
-)
-
-
 def _first_positional_argv() -> str | None:
     """Return the first non-flag, non-flag-value token in ``sys.argv[1:]``.
 
@@ -11947,6 +11912,10 @@ def _first_positional_argv() -> str | None:
     bar`` flags degrade gracefully (``bar`` may be wrongly classified as
     a positional, which at worst forces a one-time plugin discovery).
     """
+    from hermes_cli._parser import top_level_value_flag_sets
+
+    required_value_flags, optional_value_flags = top_level_value_flag_sets()
+    value_flags = required_value_flags | optional_value_flags
     argv = sys.argv[1:]
     i = 0
     while i < len(argv):
@@ -11961,7 +11930,7 @@ def _first_positional_argv() -> str | None:
             if "=" in tok:
                 i += 1
                 continue
-            if tok in _TOP_LEVEL_VALUE_FLAGS and i + 1 < len(argv):
+            if tok in value_flags and i + 1 < len(argv):
                 i += 2
                 continue
             i += 1

tests/hermes_cli/test_startup_plugin_gating.py

@@ -28,6 +28,7 @@ from unittest.mock import patch
 
 import pytest
 
+from hermes_cli._parser import build_top_level_parser, top_level_value_flag_sets
 from hermes_cli.main import (
     _BUILTIN_SUBCOMMANDS,
     _first_positional_argv,
@@ -69,6 +70,27 @@ def _live_subcommand_names() -> set[str]:
 # ── _first_positional_argv ─────────────────────────────────────────────────
 
 
+def test_value_flag_sets_match_top_level_parser():
+    required, optional = top_level_value_flag_sets()
+
+    for action in build_top_level_parser()[0]._actions:
+        if not action.option_strings or action.nargs == 0:
+            continue
+        expected = optional if action.nargs == "?" else required
+        assert set(action.option_strings) <= expected
+
+
+def test_reasoning_value_is_not_misclassified_as_subcommand(monkeypatch):
+    monkeypatch.setattr(
+        sys,
+        "argv",
+        ["hermes", "--reasoning", "high", "chat", "hello"],
+    )
+
+    assert _first_positional_argv() == "chat"
+    assert _plugin_cli_discovery_needed() is False
+
+
 
 
 # ── _plugin_cli_discovery_needed ───────────────────────────────────────────