Fix params type: accept Any (string, dict, or None) for flexibility

server.py

@@ -1,6 +1,7 @@
 import os
 import json
 import logging
+from typing import Any
 import httpx
 from fastmcp import FastMCP
 from starlette.applications import Starlette
@@ -183,7 +184,7 @@ async def list_collection_documents(
 
 
 @mcp.tool()
-async def outline_api_call(method: str, params: str = "") -> str:
+async def outline_api_call(method: str, params: Any = None) -> str:
     """Execute a raw Outline API call for any endpoint.
 
     Use the 'outline://api-reference' resource to discover available methods
@@ -191,20 +192,33 @@ async def outline_api_call(method: str, params: str = "") -> str:
 
     Args:
         method: API method name (e.g., 'documents.create', 'users.list')
-        params: JSON string of parameters to send in request body
+        params: Parameters as JSON string or dict (optional)
 
     Returns:
         JSON string with raw API response
 
     Examples:
         - method='documents.create', params='{"title": "New Doc", "collectionId": "uuid"}'
-        - method='users.list', params='{"limit": 10}'
+        - method='users.list', params={"limit": 10}
         - method='documents.delete', params='{"id": "document-uuid"}'
     """
+    # Handle params being string, dict, or None/empty
+    if params is None or params == "" or params == {}:
+        parsed_params = {}
+    elif isinstance(params, dict):
+        parsed_params = params
+    elif isinstance(params, str):
         try:
-        parsed_params = json.loads(params) if params and params.strip() else {}
+            parsed_params = json.loads(params) if params.strip() else {}
         except json.JSONDecodeError as e:
             return json.dumps({"ok": False, "error": f"Invalid JSON params: {str(e)}"})
+    else:
+        return json.dumps(
+            {
+                "ok": False,
+                "error": f"params must be string or dict, got {type(params).__name__}",
+            }
+        )
 
     result = await outline_client.call(method, parsed_params)
     return json.dumps(result, indent=2)