fix(plugin): extend runtime_mode to check settings.json and project .mcp.json (#1224)

packages/claude-code-plugin/hooks/lib/runtime_mode.py

@@ -1,40 +1,78 @@
 """Runtime mode detection — MCP vs standalone.
 
-Checks ~/.claude/mcp.json for codingbuddy MCP server entry.
+Checks multiple locations for codingbuddy MCP server entry:
+1. ~/.claude/mcp.json (global MCP config)
+2. ~/.claude/settings.json → mcpServers (global settings)
+3. {project_dir}/.mcp.json (project-level config)
+
 Used by prompt_injection, user-prompt-submit, and health_check.
 """
 import json
 import os
 from typing import Optional
 
 
-def detect_runtime_mode(home_dir: Optional[str] = None) -> str:
+def _check_mcp_json(path: str) -> bool:
+    """Check if file has mcpServers with a codingbuddy entry."""
+    try:
+        with open(path, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        mcp_servers = data.get("mcpServers", {})
+        return any("codingbuddy" in key.lower() for key in mcp_servers)
+    except (OSError, json.JSONDecodeError, TypeError):
+        return False
+
+
+def _check_settings_json(path: str) -> bool:
+    """Check settings.json mcpServers for a codingbuddy entry."""
+    try:
+        with open(path, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        mcp_servers = data.get("mcpServers", {})
+        return any("codingbuddy" in key.lower() for key in mcp_servers)
+    except (OSError, json.JSONDecodeError, TypeError):
+        return False
+
+
+def detect_runtime_mode(
+    home_dir: Optional[str] = None,
+    project_dir: Optional[str] = None,
+) -> str:
     """Detect if CodingBuddy MCP server is configured.
 
-    Checks ~/.claude/mcp.json for an entry containing 'codingbuddy'.
+    Checks three locations in order and returns 'mcp' on first match:
+    1. ~/.claude/mcp.json (global MCP config)
+    2. ~/.claude/settings.json → mcpServers (global settings)
+    3. {project_dir}/.mcp.json (project-level config)
 
     Args:
         home_dir: Override home directory (for testing).
+        project_dir: Project directory to check for .mcp.json.
 
     Returns:
         'mcp' if codingbuddy MCP server found, 'standalone' otherwise.
     """
     home = home_dir or os.path.expanduser("~")
-    mcp_json_path = os.path.join(home, ".claude", "mcp.json")
 
-    try:
-        with open(mcp_json_path, "r", encoding="utf-8") as f:
-            data = json.load(f)
+    # 1. ~/.claude/mcp.json (global MCP config)
+    if _check_mcp_json(os.path.join(home, ".claude", "mcp.json")):
+        return "mcp"
 
-        mcp_servers = data.get("mcpServers", {})
-        for key in mcp_servers:
-            if "codingbuddy" in key.lower():
-                return "mcp"
-        return "standalone"
-    except (OSError, json.JSONDecodeError, TypeError):
-        return "standalone"
+    # 2. ~/.claude/settings.json → mcpServers
+    if _check_settings_json(os.path.join(home, ".claude", "settings.json")):
+        return "mcp"
+
+    # 3. {project_dir}/.mcp.json (project-level)
+    if project_dir:
+        if _check_mcp_json(os.path.join(project_dir, ".mcp.json")):
+            return "mcp"
+
+    return "standalone"
 
 
-def is_mcp_available(home_dir: Optional[str] = None) -> bool:
+def is_mcp_available(
+    home_dir: Optional[str] = None,
+    project_dir: Optional[str] = None,
+) -> bool:
     """Convenience wrapper: True if MCP mode detected."""
-    return detect_runtime_mode(home_dir) == "mcp"
+    return detect_runtime_mode(home_dir, project_dir) == "mcp"

packages/claude-code-plugin/tests/test_runtime_mode.py

@@ -15,12 +15,32 @@ def fake_home(tmp_path):
     return tmp_path
 
 
+@pytest.fixture()
+def fake_project(tmp_path):
+    """Create a fake project directory."""
+    project_dir = tmp_path / "my-project"
+    project_dir.mkdir()
+    return project_dir
+
+
 def _write_mcp_json(home_path, data):
     mcp_path = os.path.join(str(home_path), ".claude", "mcp.json")
     with open(mcp_path, "w", encoding="utf-8") as f:
         json.dump(data, f)
 
 
+def _write_settings_json(home_path, data):
+    settings_path = os.path.join(str(home_path), ".claude", "settings.json")
+    with open(settings_path, "w", encoding="utf-8") as f:
+        json.dump(data, f)
+
+
+def _write_project_mcp_json(project_path, data):
+    mcp_path = os.path.join(str(project_path), ".mcp.json")
+    with open(mcp_path, "w", encoding="utf-8") as f:
+        json.dump(data, f)
+
+
 class TestDetectRuntimeMode:
     def test_returns_mcp_when_codingbuddy_entry_exists(self, fake_home):
         _write_mcp_json(fake_home, {
@@ -61,6 +81,126 @@ def test_returns_standalone_when_mcp_servers_missing(self, fake_home):
         assert detect_runtime_mode(str(fake_home)) == "standalone"
 
 
+class TestSettingsJsonDetection:
+    def test_returns_mcp_from_settings_json(self, fake_home):
+        """settings.json with codingbuddy mcpServers → 'mcp'."""
+        _write_settings_json(fake_home, {
+            "mcpServers": {
+                "codingbuddy": {"command": "npx", "args": ["codingbuddy"]}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home)) == "mcp"
+
+    def test_settings_json_case_insensitive(self, fake_home):
+        _write_settings_json(fake_home, {
+            "mcpServers": {
+                "CodingBuddy-MCP": {"command": "node", "args": ["server.js"]}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home)) == "mcp"
+
+    def test_settings_json_without_codingbuddy_returns_standalone(self, fake_home):
+        """settings.json without codingbuddy → still checks next, returns standalone."""
+        _write_settings_json(fake_home, {
+            "mcpServers": {
+                "other-tool": {"command": "npx", "args": ["other"]}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home)) == "standalone"
+
+    def test_settings_json_invalid_json(self, fake_home):
+        settings_path = os.path.join(str(fake_home), ".claude", "settings.json")
+        with open(settings_path, "w", encoding="utf-8") as f:
+            f.write("not json!")
+        assert detect_runtime_mode(str(fake_home)) == "standalone"
+
+    def test_settings_json_no_mcp_servers_key(self, fake_home):
+        _write_settings_json(fake_home, {"permissions": {"allow": []}})
+        assert detect_runtime_mode(str(fake_home)) == "standalone"
+
+
+class TestProjectMcpJsonDetection:
+    def test_returns_mcp_from_project_mcp_json(self, fake_home, fake_project):
+        """project .mcp.json with codingbuddy → 'mcp'."""
+        _write_project_mcp_json(fake_project, {
+            "mcpServers": {
+                "codingbuddy": {"command": "npx", "args": ["codingbuddy"]}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home), str(fake_project)) == "mcp"
+
+    def test_project_mcp_json_case_insensitive(self, fake_home, fake_project):
+        _write_project_mcp_json(fake_project, {
+            "mcpServers": {
+                "CodingBuddy-Rules": {"command": "npx"}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home), str(fake_project)) == "mcp"
+
+    def test_project_mcp_json_without_codingbuddy(self, fake_home, fake_project):
+        _write_project_mcp_json(fake_project, {
+            "mcpServers": {
+                "some-other-server": {"command": "npx"}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home), str(fake_project)) == "standalone"
+
+    def test_project_dir_none_skips_check(self, fake_home):
+        """When project_dir is None, skip project-level check."""
+        assert detect_runtime_mode(str(fake_home), None) == "standalone"
+
+    def test_project_mcp_json_missing(self, fake_home, fake_project):
+        assert detect_runtime_mode(str(fake_home), str(fake_project)) == "standalone"
+
+
+class TestPriorityOrder:
+    def test_mcp_json_takes_precedence_over_settings(self, fake_home):
+        """mcp.json is checked first — settings.json is not needed."""
+        _write_mcp_json(fake_home, {
+            "mcpServers": {
+                "codingbuddy": {"command": "npx"}
+            }
+        })
+        _write_settings_json(fake_home, {
+            "mcpServers": {
+                "other-server": {"command": "npx"}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home)) == "mcp"
+
+    def test_settings_json_checked_when_mcp_json_absent(self, fake_home):
+        """Falls through to settings.json when mcp.json has no match."""
+        _write_mcp_json(fake_home, {
+            "mcpServers": {
+                "other-server": {"command": "npx"}
+            }
+        })
+        _write_settings_json(fake_home, {
+            "mcpServers": {
+                "codingbuddy": {"command": "npx"}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home)) == "mcp"
+
+    def test_project_mcp_json_checked_last(self, fake_home, fake_project):
+        """Falls through to project .mcp.json when home configs have no match."""
+        _write_mcp_json(fake_home, {"mcpServers": {"other": {"command": "x"}}})
+        _write_settings_json(fake_home, {"mcpServers": {"other2": {"command": "x"}}})
+        _write_project_mcp_json(fake_project, {
+            "mcpServers": {
+                "codingbuddy": {"command": "npx"}
+            }
+        })
+        assert detect_runtime_mode(str(fake_home), str(fake_project)) == "mcp"
+
+    def test_all_three_empty_returns_standalone(self, fake_home, fake_project):
+        """All 3 locations empty → 'standalone'."""
+        _write_mcp_json(fake_home, {"mcpServers": {}})
+        _write_settings_json(fake_home, {"mcpServers": {}})
+        _write_project_mcp_json(fake_project, {"mcpServers": {}})
+        assert detect_runtime_mode(str(fake_home), str(fake_project)) == "standalone"
+
+
 class TestIsMcpAvailable:
     def test_returns_true_when_mcp(self, fake_home):
         _write_mcp_json(fake_home, {
@@ -72,3 +212,19 @@ def test_returns_true_when_mcp(self, fake_home):
 
     def test_returns_false_when_standalone(self, tmp_path):
         assert is_mcp_available(str(tmp_path)) is False
+
+    def test_returns_true_from_settings_json(self, fake_home):
+        _write_settings_json(fake_home, {
+            "mcpServers": {
+                "codingbuddy": {"command": "npx"}
+            }
+        })
+        assert is_mcp_available(str(fake_home)) is True
+
+    def test_returns_true_from_project_mcp_json(self, fake_home, fake_project):
+        _write_project_mcp_json(fake_project, {
+            "mcpServers": {
+                "codingbuddy": {"command": "npx"}
+            }
+        })
+        assert is_mcp_available(str(fake_home), str(fake_project)) is True