From af84b1b8c0278f4c3a2fa208ebf1efbad54953e1 Mon Sep 17 00:00:00 2001
From: Yohei Nishikubo <yohei@me.com>
Date: Wed, 25 Mar 2026 09:40:21 +0900
Subject: [PATCH] fix(Gemini): update ToolCallRequest and OpenAICompatProvider
 to handle thought signatures in extra_content

---
 nanobot/providers/base.py                    | 16 +++++++++++++++-
 nanobot/providers/openai_compat_provider.py  |  7 +++++++
 tests/agent/test_gemini_thought_signature.py |  2 +-
 tests/providers/test_litellm_kwargs.py       |  4 ++--
 4 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/nanobot/providers/base.py b/nanobot/providers/base.py
index 046458dec..1fd610b91 100644
--- a/nanobot/providers/base.py
+++ b/nanobot/providers/base.py
@@ -30,7 +30,21 @@ class ToolCallRequest:
             },
         }
         if self.provider_specific_fields:
-            tool_call["provider_specific_fields"] = self.provider_specific_fields
+            # Gemini OpenAI compatibility expects thought signatures in extra_content.google.
+            if "thought_signature" in self.provider_specific_fields:
+                tool_call["extra_content"] = {
+                    "google": {
+                        "thought_signature": self.provider_specific_fields["thought_signature"],
+                    }
+                }
+                other_fields = {
+                    k: v for k, v in self.provider_specific_fields.items()
+                    if k != "thought_signature"
+                }
+                if other_fields:
+                    tool_call["provider_specific_fields"] = other_fields
+            else:
+                tool_call["provider_specific_fields"] = self.provider_specific_fields
         if self.function_provider_specific_fields:
             tool_call["function"]["provider_specific_fields"] = self.function_provider_specific_fields
         return tool_call
diff --git a/nanobot/providers/openai_compat_provider.py b/nanobot/providers/openai_compat_provider.py
index 866e05ef8..1157e176d 100644
--- a/nanobot/providers/openai_compat_provider.py
+++ b/nanobot/providers/openai_compat_provider.py
@@ -43,6 +43,13 @@ def _coerce_dict(value: Any) -> dict[str, Any] | None:
 def _extract_tool_call_fields(tc: Any) -> tuple[dict[str, Any] | None, dict[str, Any] | None]:
     """Extract provider-specific metadata from a tool call object."""
     provider_specific_fields = _coerce_dict(_get_attr_or_item(tc, "provider_specific_fields"))
+    extra_content = _coerce_dict(_get_attr_or_item(tc, "extra_content"))
+    google_content = _coerce_dict(_get_attr_or_item(extra_content, "google")) if extra_content else None
+    if google_content:
+        provider_specific_fields = {
+            **(provider_specific_fields or {}),
+            **google_content,
+        }
     function = _get_attr_or_item(tc, "function")
     function_provider_specific_fields = _coerce_dict(
         _get_attr_or_item(function, "provider_specific_fields")
diff --git a/tests/agent/test_gemini_thought_signature.py b/tests/agent/test_gemini_thought_signature.py
index 35739602a..f4b279b65 100644
--- a/tests/agent/test_gemini_thought_signature.py
+++ b/tests/agent/test_gemini_thought_signature.py
@@ -14,6 +14,6 @@ def test_tool_call_request_serializes_provider_fields() -> None:
 
     message = tool_call.to_openai_tool_call()
 
-    assert message["provider_specific_fields"] == {"thought_signature": "signed-token"}
+    assert message["extra_content"] == {"google": {"thought_signature": "signed-token"}}
     assert message["function"]["provider_specific_fields"] == {"inner": "value"}
     assert message["function"]["arguments"] == '{"path": "todo.md"}'
diff --git a/tests/providers/test_litellm_kwargs.py b/tests/providers/test_litellm_kwargs.py
index 4d1572075..e912a7bfd 100644
--- a/tests/providers/test_litellm_kwargs.py
+++ b/tests/providers/test_litellm_kwargs.py
@@ -40,7 +40,7 @@ def _fake_tool_call_response() -> SimpleNamespace:
         id="call_123",
         index=0,
         function=function,
-        provider_specific_fields={"thought_signature": "signed-token"},
+        extra_content={"google": {"thought_signature": "signed-token"}},
     )
     message = SimpleNamespace(
         content=None,
@@ -160,7 +160,7 @@ async def test_openai_compat_preserves_provider_specific_fields_on_tool_calls()
     assert tool_call.function_provider_specific_fields == {"inner": "value"}
 
     serialized = tool_call.to_openai_tool_call()
-    assert serialized["provider_specific_fields"] == {"thought_signature": "signed-token"}
+    assert serialized["extra_content"] == {"google": {"thought_signature": "signed-token"}}
     assert serialized["function"]["provider_specific_fields"] == {"inner": "value"}