From c8cc38f657372e1ed65282cd074aab84f52f0f9a Mon Sep 17 00:00:00 2001
From: Deepanshu Pal <40927968+DeepanshuPal@users.noreply.github.com>
Date: Wed, 7 Oct 2026 02:10:23 +0530
Subject: [PATCH 1/2] types: make ChatRequest serialization None-safe for tools
 without parameters

---
 ollama/_types.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/ollama/_types.py b/ollama/_types.py
index cf7264b5..5c0ff7bf 100644
--- a/ollama/_types.py
+++ b/ollama/_types.py
@@ -390,8 +390,9 @@ def serialize_model(self, nxt):
     output = nxt(self)
     if output.get('tools'):
       for tool in output['tools']:
-        if 'function' in tool and 'parameters' in tool['function'] and 'defs' in tool['function']['parameters']:
-          tool['function']['parameters']['$defs'] = tool['function']['parameters'].pop('defs')
+        parameters = (tool.get('function') or {}).get('parameters')
+        if parameters and 'defs' in parameters:
+          parameters['$defs'] = parameters.pop('defs')
     return output
 
   messages: Optional[Sequence[Union[Mapping[str, Any], Message]]] = None

From c11bce679606631460e8603e4cc1ebf3988f92e8 Mon Sep 17 00:00:00 2001
From: Deepanshu Pal <40927968+DeepanshuPal@users.noreply.github.com>
Date: Wed, 7 Oct 2026 02:11:00 +0530
Subject: [PATCH 2/2] tests: cover ChatRequest serialization with tools missing
 function or parameters

Add tests for ChatRequest serialization with tools and parameters.
---
 tests/test_type_serialization.py | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/tests/test_type_serialization.py b/tests/test_type_serialization.py
index e1af3512..319b2354 100644
--- a/tests/test_type_serialization.py
+++ b/tests/test_type_serialization.py
@@ -4,7 +4,7 @@
 
 import pytest
 
-from ollama._types import ChatRequest, CreateRequest, GenerateRequest, Image
+from ollama._types import ChatRequest, CreateRequest, GenerateRequest, Image, Tool
 
 
 def test_image_serialization_bytes():
@@ -122,3 +122,17 @@ def test_think_boolean_serialization():
   assert ChatRequest(model='test-model', think=True).model_dump(exclude_none=True)['think'] is True
   assert ChatRequest(model='test-model', think=False).model_dump(exclude_none=True)['think'] is False
   assert 'think' not in ChatRequest(model='test-model', think=None).model_dump(exclude_none=True)
+
+
+def test_chat_request_dump_with_tools_missing_function_or_parameters():
+  req = ChatRequest(model='test-model', tools=[Tool(function=Tool.Function(name='f')), Tool()])
+  assert req.model_dump()['tools'][0]['function']['name'] == 'f'
+  assert req.model_dump(exclude_none=True)['tools'][0]['function'] == {'name': 'f'}
+  assert 'tools' in req.model_dump_json()
+
+
+def test_chat_request_renames_defs_for_tool_parameters():
+  tool = Tool(function=Tool.Function(name='f', parameters=Tool.Function.Parameters(defs={'A': {'type': 'string'}})))
+  params = ChatRequest(model='test-model', tools=[tool]).model_dump()['tools'][0]['function']['parameters']
+  assert params['$defs'] == {'A': {'type': 'string'}}
+  assert 'defs' not in params