Merge pull request #246 from druellan/disabledTools

Feat: Tools can be filtered out using the `disabledTools` configuration option in the server declaration

Author: tjbck

CHANGELOG.md

@@ -12,6 +12,12 @@ All notable changes to this project will be documented in this file.
 The format is based on Keep a Changelog,
 and this project adheres to Semantic Versioning.
 
+## [0.0.18] - 2025-09-07
+
+### Added
+
+- 🔧 **Support for disabling specific tools**: Tools can be filtered out using the `disabledTools` configuration option in the server declaration.
+
 ## [0.0.17] - 2025-07-22
 
 ### Added

README.md

@@ -103,7 +103,8 @@ Example config.json:
     },
     "time": {
       "command": "uvx",
-      "args": ["mcp-server-time", "--local-timezone=America/New_York"]
+      "args": ["mcp-server-time", "--local-timezone=America/New_York"],
+      "disabledTools": ["convert_time"] // Disable specific tools if needed
     },
     "mcp_sse": {
       "type": "sse", // Explicitly define type

src/mcpo/main.py

@@ -71,6 +71,16 @@ def validate_server_config(server_name: str, server_cfg: Dict[str, Any]) -> None
         # Fallback for old SSE config without explicit type
         pass
     else:
+        raise ValueError(f"Server '{server_name}' must have either 'command' for stdio or 'type' and 'url' for remote servers")
+    
+    # Validate disabledTools
+    disabled_tools = server_cfg.get("disabled_tools")
+    if disabled_tools is not None:
+        if not isinstance(disabled_tools, list):
+            raise ValueError(f"Server '{server_name}' 'disabledTools' must be a list")
+        for tool_name in disabled_tools:
+            if not isinstance(tool_name, str):
+                raise ValueError(f"Server '{server_name}' 'disabledTools' must contain only strings")
         raise ValueError(
             f"Server '{server_name}' must have either 'command' for stdio or 'type' and 'url' for remote servers"
         )
@@ -167,6 +177,10 @@ def create_sub_app(
     sub_app.state.api_dependency = api_dependency
     sub_app.state.connection_timeout = connection_timeout
 
+    # Store list of tools to be disabled, if present
+    sub_app.state.disabled_tools = server_cfg.get("disabled_tools", [])
+
+    
     # Store client header forwarding configuration
     sub_app.state.client_header_forwarding = server_cfg.get(
         "client_header_forwarding", {"enabled": False}
@@ -175,6 +189,7 @@ def create_sub_app(
     # Store OAuth configuration if present
     sub_app.state.oauth_config = server_cfg.get("oauth")
 
+
     return sub_app
 
 
@@ -346,6 +361,15 @@ async def create_dynamic_endpoints(app: FastAPI, api_dependency=None):
 
     tools_result = await session.list_tools()
     tools = tools_result.tools
+    
+    # Filter out disabled tools
+    disabled_tools = getattr(app.state, "disabled_tools", [])
+    if disabled_tools:
+        original_count = len(tools)
+        tools = [tool for tool in tools if tool.name not in disabled_tools]
+        filtered_count = original_count - len(tools)
+        if filtered_count > 0:
+            logger.info(f"Filtered out {filtered_count} tool(s) for server '{app.title}': {disabled_tools}")
 
     for tool in tools:
         endpoint_name = tool.name

src/mcpo/tests/test_hot_reload.py

@@ -42,6 +42,19 @@ def test_validate_server_config_missing_url():
         validate_server_config("test_server", config)
 
 
+def test_validate_server_config_disabled_tools_valid():
+    """Test validation of server configuration with a valid disabledTools."""
+    config = {"command": "echo", "args": ["hello"], "disabledTools": ["search-web"]}
+    validate_server_config("test_server", config)
+
+
+def test_validate_server_config_disabled_tools_invalid():
+    """Test validation fails for an invalid disabledTools."""
+    config = {"command": "echo", "args": ["hello"], "disabledTools": "not-a-list"}
+    with pytest.raises(ValueError, match="'disabledTools' must be a list"):
+        validate_server_config("test_server", config)
+
+
 def test_load_config_valid():
     """Test loading a valid config file."""
     config_data = {