diff --git a/src/mcpo/tests/test_main.py b/src/mcpo/tests/test_main.py
index e0b8cb3..a7cfe5f 100644
--- a/src/mcpo/tests/test_main.py
+++ b/src/mcpo/tests/test_main.py
@@ -1,6 +1,6 @@
 import pytest
 from pydantic import BaseModel, Field
-from typing import Any, List, Dict
+from typing import Any, List, Dict, Union
 
 from mcpo.utils.main import _process_schema_property
 
@@ -64,6 +64,17 @@ def test_process_simple_number():
     assert result_field.default == expected_field.default
 
 
+def test_process_null():
+    schema = {"type": "null"}
+    expected_type = None
+    expected_field = Field(default=..., description="")
+    result_type, result_field = _process_schema_property(
+        _model_cache, schema, "test", "prop", True
+    )
+    assert result_type == expected_type
+    assert result_field.default == expected_field.default
+
+
 def test_process_unknown_type():
     schema = {"type": "unknown"}
     expected_type = Any
@@ -226,8 +237,11 @@ def test_model_caching():
     assert len(_model_cache) == 2  # Only two unique models created
 
 
-def test_multi_type_property():
-    schema = {"type": ["string", "number"], "description": "A property with multiple types"}
+def test_multi_type_property_with_list():
+    schema = {
+        "type": ["string", "number"],
+        "description": "A property with multiple types",
+    }
     expected_field = Field(default=..., description="A property with multiple types")
     result_type, result_field = _process_schema_property(
         _model_cache, schema, "test", "multi_type", True
@@ -243,3 +257,56 @@ def test_multi_type_property():
     # Check field properties
     assert result_field.default == expected_field.default
     assert result_field.description == expected_field.description
+
+
+def test_multi_type_property_with_any_of():
+    schema = {
+        "anyOf": [
+            {
+                "type": "object",
+                "properties": {
+                    "name": {
+                        "type": "string",
+                        "description": "The name of the function to call",
+                    },
+                    "arguments": {
+                        "type": "string",
+                        "description": "The arguments to pass to the function, as a JSON string",
+                        "default": "{}",
+                    },
+                },
+                "required": ["name"],
+            },
+            {
+                "type": "object",
+                "properties": {
+                    "function_id": {
+                        "type": "int",
+                        "description": "The id of the function to call",
+                    },
+                },
+                "required": ["function_id"],
+            },
+            {
+                "type": "string",
+                "enum": ["auto", "none"],
+                "description": "Control function calling behavior",
+            },
+        ],
+        "description": "A property with multiple types",
+    }
+    result_type, result_field = _process_schema_property(
+        _model_cache, schema, "test", "multi_type", True
+    )
+
+    # Check if the resulting type is a Union
+    assert result_type.__origin__ == Union
+
+    # Check if the Union has the correct number of types
+    assert len(result_type.__args__) == 3
+    assert len(result_type.__args__[0].model_fields) == 2
+    assert len(result_type.__args__[1].model_fields) == 1
+    assert result_type.__args__[2] is str
+
+    # assert result_field parameter config
+    assert result_field.description == "A property with multiple types"
diff --git a/src/mcpo/utils/main.py b/src/mcpo/utils/main.py
index f828150..e15fe7d 100644
--- a/src/mcpo/utils/main.py
+++ b/src/mcpo/utils/main.py
@@ -2,16 +2,19 @@ import json
 from typing import Any, Dict, ForwardRef, List, Optional, Type, Union
 
 from fastapi import HTTPException
+
 from mcp import ClientSession, types
-from mcp.shared.exceptions import McpError
 from mcp.types import (
-    INTERNAL_ERROR,
-    INVALID_PARAMS,
+    CallToolResult,
+    PARSE_ERROR,
     INVALID_REQUEST,
     METHOD_NOT_FOUND,
-    PARSE_ERROR,
-    CallToolResult,
+    INVALID_PARAMS,
+    INTERNAL_ERROR,
 )
+
+from mcp.shared.exceptions import McpError
+
 from pydantic import Field, create_model
 from pydantic.fields import FieldInfo
 
@@ -72,6 +75,21 @@ def _process_schema_property(
     default_value = ... if is_required else prop_schema.get("default", None)
     pydantic_field = Field(default=default_value, description=prop_desc)
 
+    # Handle the case where prop_type is missing but 'anyOf' key exists
+    # In this case, use data type from 'anyOf' to determine the type hint
+    if "anyOf" in prop_schema:
+        type_hints = []
+        for i, schema_option in enumerate(prop_schema["anyOf"]):
+            type_hint, _ = _process_schema_property(
+                _model_cache,
+                schema_option,
+                f"{model_name_prefix}_{prop_name}",
+                f"choice_{i}",
+                False,
+            )
+            type_hints.append(type_hint)
+        return Union[tuple(type_hints)], pydantic_field
+
     # Handle the case where prop_type is a list of types, e.g. ['string', 'number']
     if isinstance(prop_type, list):
         # Create a Union of all the types
@@ -147,6 +165,8 @@ def _process_schema_property(
         return bool, pydantic_field
     elif prop_type == "number":
         return float, pydantic_field
+    elif prop_type == "null":
+        return None, pydantic_field
     else:
         return Any, pydantic_field