feat: add api_call pass-through tool and API reference resource

- Add single pass-through tool following blueprint 'escape hatch' pattern
- Add monarch://api-reference resource with available methods documentation
- Fix dependency: use monarchmoney>=0.1.15 instead of monarchmoneycommunity
- Add JSON error handling for malformed params

pyproject.toml

@@ -19,7 +19,7 @@ requires-python = ">=3.12"
 dependencies = [
     "mcp[cli]>=1.0.0",
     "fastmcp>=0.4.1",
-    "monarchmoneycommunity>=0.1.0",
+    "monarchmoney>=0.1.15",
     "gql>=4.0",
     "python-dotenv>=1.0.0",
     "pydantic>=2.0.0",

src/monarch_mcp_custom/server.py

@@ -191,6 +191,85 @@ async def refresh_accounts(reason: Optional[str] = None) -> str:
     return serialize_json(result)
 
 
+# --- API Reference Resource ---
+
+API_REFERENCE = """
+# Monarch Money API Reference
+Full method signatures: https://github.com/hammem/monarchmoney
+
+## Transaction Operations
+- get_transactions(limit=100, offset=0, start_date=None, end_date=None, search='', category_ids=[], account_ids=[])
+- get_transaction_splits(transaction_id: str)
+- update_transaction_splits(transaction_id: str, split_data: List[Dict])
+- create_transaction(date, account_id, amount, merchant_name, category_id, notes='', update_balance=False)
+- update_transaction(transaction_id, category_id=None, merchant_name=None, amount=None, date=None, notes=None)
+- delete_transaction(transaction_id: str)
+- get_transaction_details(transaction_id: str)
+
+## Categories & Tags
+- get_transaction_categories()
+- get_transaction_category_groups()
+- create_transaction_category(group_id, transaction_category_name, ...)
+- create_transaction_tag(name, color)
+- set_transaction_tags(transaction_id, tag_ids)
+- get_transaction_tags()
+
+## Accounts
+- get_accounts()
+- get_account_holdings(account_id: int)
+- create_manual_account(account_type, account_sub_type, is_in_net_worth, account_name, account_balance=0)
+- update_account(account_id, account_name=None, account_balance=None, ...)
+
+## Budget & Cashflow
+- get_budgets(start_date=None, end_date=None)
+- get_cashflow(limit=100, start_date=None, end_date=None)
+- get_recurring_transactions(start_date=None, end_date=None)
+
+## Sync
+- request_accounts_refresh(account_ids: List[str])
+- is_accounts_refresh_complete(account_ids=None)
+"""
+
+
+@mcp.resource("monarch://api-reference")
+def get_api_docs() -> str:
+    """Returns the API documentation for using the 'api_call' tool."""
+    return API_REFERENCE
+
+
+# --- Pass-through Tool ---
+
+
+@mcp.tool()
+@retry_on_auth_error()
+async def api_call(method: str, params: str = "{}") -> str:
+    """
+    Execute a raw method call to the Monarch Money API.
+    
+    Args:
+        method: The method name to call (e.g., 'get_transaction_splits', 'update_transaction_splits')
+        params: JSON string of parameters to pass to the method
+    
+    Returns:
+        JSON result from the API call
+    
+    Example:
+        api_call(method="get_transaction_categories", params="{}")
+        api_call(method="get_transaction_splits", params='{"transaction_id": "12345"}')
+        api_call(method="update_transaction_splits", params='{"transaction_id": "12345", "split_data": [{"amount": -50.00, "categoryId": "100", "merchantName": "Groceries"}]}')
+    """
+    client = await get_authenticated_client()
+    method_func = getattr(client, method, None)
+    if not method_func:
+        return serialize_json({"error": f"Method '{method}' not found"})
+    try:
+        parsed_params = json.loads(params) if params else {}
+    except json.JSONDecodeError as e:
+        return serialize_json({"error": f"Invalid JSON in params: {e}"})
+    result = await method_func(**parsed_params)
+    return serialize_json(result)
+
+
 # --- Health Check Endpoint ---