fix(plugins): skip foreign-harness manifest dirs during discovery

hermes_cli/plugins.py

@@ -682,6 +682,21 @@ def _get_enabled_plugins() -> Optional[set]:
 
 _VALID_PLUGIN_KINDS: Set[str] = {"standalone", "backend", "exclusive", "platform", "model-provider"}
 
+# Per-harness manifest directories that plugin repos ship for OTHER agent
+# harnesses (Claude Code, Codex, Cursor, Devin, Kimi — e.g. obra/superpowers
+# keeps one plugin.json per harness inside them). Their plugin.json is not an
+# Agent Plugins v1 manifest and can never validate, so attempting it on every
+# discovery pass only spams warnings (#101962). Directory discovery skips
+# them; a plugin's real Hermes manifest (.hermes-plugin/plugin.yaml or a
+# top-level plugin.yaml/plugin.json) is unaffected.
+_FOREIGN_HARNESS_MANIFEST_DIRS = frozenset({
+    ".claude-plugin",
+    ".codex-plugin",
+    ".cursor-plugin",
+    ".devin-plugin",
+    ".kimi-plugin",
+})
+
 
 def _portable_skill_namespace(key: str) -> str:
     """Return a readable, collision-resistant namespace for a portable plugin."""
@@ -4709,6 +4724,11 @@ def _scan_directory_level(
                 continue
             if depth == 0 and skip_names and child.name in skip_names:
                 continue
+            if child.name in _FOREIGN_HARNESS_MANIFEST_DIRS:
+                logger.debug(
+                    "Skipping %s (foreign-harness manifest convention)", child
+                )
+                continue
             manifest_file = child / "plugin.yaml"
             if not manifest_file.exists():
                 manifest_file = child / "plugin.yml"

tests/hermes_cli/test_plugin_scanner_recursion.py

@@ -8,6 +8,7 @@
 
 from __future__ import annotations
 
+import json
 from pathlib import Path
 from typing import Any, Dict
 
@@ -113,6 +114,74 @@ def test_depth_cap_two(self, tmp_path, monkeypatch):
         assert non_bundled == []
 
 
+# ── Foreign-harness manifest dirs (#101962) ────────────────────────────────
+
+
+class TestForeignHarnessManifestDirs:
+    def test_foreign_harness_dirs_skipped_without_warnings(
+        self, tmp_path, monkeypatch, caplog
+    ):
+        """Multi-harness plugin repos (e.g. obra/superpowers) ship one
+        ``plugin.json`` per OTHER agent harness inside ``.claude-plugin/``,
+        ``.codex-plugin/`` etc. Those manifests can never satisfy the Agent
+        Plugins v1 schema, so scanning them warned on every discovery pass.
+        They must be skipped silently; the plugin's real Hermes manifest
+        (``.hermes-plugin/plugin.yaml``) is still discovered."""
+        import os
+        hermes_home = Path(os.environ["HERMES_HOME"])  # set by hermetic conftest fixture
+        sp = hermes_home / "plugins" / "superpowers"
+        (sp / ".hermes-plugin").mkdir(parents=True)
+        (sp / ".hermes-plugin" / "plugin.yaml").write_text(
+            yaml.dump(
+                {
+                    "name": "superpowers",
+                    "version": "6.3.0",
+                    "description": "multi-harness plugin",
+                }
+            )
+        )
+        for harness in (
+            ".claude-plugin",
+            ".codex-plugin",
+            ".cursor-plugin",
+            ".devin-plugin",
+            ".kimi-plugin",
+        ):
+            harness_dir = sp / harness
+            harness_dir.mkdir(parents=True)
+            (harness_dir / "plugin.json").write_text(
+                json.dumps({"name": "superpowers", "version": "6.3.0"})
+            )
+
+        with caplog.at_level("WARNING", logger="hermes_cli.plugins"):
+            mgr = PluginManager()
+            mgr.discover_and_load()
+
+        assert "superpowers/.hermes-plugin" in mgr._plugins
+        parse_warnings = [
+            r for r in caplog.records if "Failed to parse" in r.getMessage()
+        ]
+        assert parse_warnings == []
+
+    def test_broken_portable_plugin_still_warns(self, tmp_path, monkeypatch, caplog):
+        """A genuinely broken portable plugin.json (not a foreign-harness
+        convention directory) must still surface its parse warning."""
+        import os
+        hermes_home = Path(os.environ["HERMES_HOME"])  # set by hermetic conftest fixture
+        broken = hermes_home / "plugins" / "broken-portable"
+        broken.mkdir(parents=True)
+        (broken / "plugin.json").write_text(json.dumps({"name": "broken"}))
+
+        with caplog.at_level("WARNING", logger="hermes_cli.plugins"):
+            mgr = PluginManager()
+            mgr.discover_and_load()
+
+        assert any(
+            "Failed to parse" in r.getMessage() and "broken-portable" in r.getMessage()
+            for r in caplog.records
+        )
+
+
 
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