fix(gemini): nest google extra body for sdk

providers/gemini/request.py

@@ -2,7 +2,8 @@
 
 from __future__ import annotations
 
-from typing import Any
+from copy import deepcopy
+from typing import Any, cast
 
 from loguru import logger
 
@@ -11,6 +12,24 @@ from core.anthropic.conversion import OpenAIConversionError
 from providers.exceptions import InvalidRequestError
 
 
+def _ensure_dict(container: dict[str, Any], key: str) -> dict[str, Any]:
+    value = container.get(key)
+    if isinstance(value, dict):
+        return cast(dict[str, Any], value)
+    nested: dict[str, Any] = {}
+    container[key] = nested
+    return nested
+
+
+def _apply_thinking_config(extra_body: dict[str, Any]) -> None:
+    # OpenAI's SDK merges its ``extra_body`` argument into the request JSON.
+    # Google expects its extension fields under a literal JSON ``extra_body`` key.
+    literal_extra_body = _ensure_dict(extra_body, "extra_body")
+    google_section = _ensure_dict(literal_extra_body, "google")
+    thinking_cfg = _ensure_dict(google_section, "thinking_config")
+    thinking_cfg.setdefault("include_thoughts", True)
+
+
 def build_request_body(request_data: Any, *, thinking_enabled: bool) -> dict:
     """Build OpenAI-format request body from an Anthropic request for Gemini."""
     logger.debug(
@@ -30,16 +49,12 @@ def build_request_body(request_data: Any, *, thinking_enabled: bool) -> dict:
 
     extra_body: dict[str, Any] = {}
     request_extra = getattr(request_data, "extra_body", None)
-    if request_extra:
-        extra_body.update(request_extra)
+    if isinstance(request_extra, dict):
+        extra_body.update(deepcopy(request_extra))
 
     if thinking_enabled:
         body["reasoning_effort"] = "high"
-        google_section = extra_body.setdefault("google", {})
-        if isinstance(google_section, dict):
-            thinking_cfg = google_section.setdefault("thinking_config", {})
-            if isinstance(thinking_cfg, dict):
-                thinking_cfg.setdefault("include_thoughts", True)
+        _apply_thinking_config(extra_body)
     else:
         body["reasoning_effort"] = "none"
 

tests/providers/test_gemini.py

@@ -31,6 +31,14 @@ class MockRequest:
             setattr(self, key, value)
 
 
+def _simulate_openai_sdk_wire_json(body: dict) -> dict:
+    wire = {key: value for key, value in body.items() if key != "extra_body"}
+    sdk_extra = body.get("extra_body")
+    if isinstance(sdk_extra, dict):
+        wire.update(sdk_extra)
+    return wire
+
+
 @pytest.fixture
 def gemini_config():
     return ProviderConfig(
@@ -94,11 +102,31 @@ def test_build_request_body_basic(gemini_provider):
     assert body["reasoning_effort"] == "high"
     eb = body.get("extra_body")
     assert isinstance(eb, dict)
-    gc = eb.get("google")
+    literal_extra_body = eb.get("extra_body")
+    assert isinstance(literal_extra_body, dict)
+    gc = literal_extra_body.get("google")
     assert isinstance(gc, dict)
     tc = gc.get("thinking_config")
     assert isinstance(tc, dict)
     assert tc.get("include_thoughts") is True
+    assert "google" not in eb
+
+
+def test_build_request_body_sdk_wire_json_has_literal_extra_body(gemini_provider):
+    """Regression for issue #542: SDK merge must not send top-level google."""
+    req = MockRequest()
+
+    body = gemini_provider._build_request_body(req)
+    wire_json = _simulate_openai_sdk_wire_json(body)
+
+    assert "google" not in wire_json
+    literal_extra_body = wire_json.get("extra_body")
+    assert isinstance(literal_extra_body, dict)
+    google = literal_extra_body.get("google")
+    assert isinstance(google, dict)
+    thinking_config = google.get("thinking_config")
+    assert isinstance(thinking_config, dict)
+    assert thinking_config.get("include_thoughts") is True
 
 
 def test_build_request_body_global_disable_sets_reasoning_none():
@@ -128,6 +156,39 @@ def test_build_request_body_preserves_caller_extra_body(gemini_provider):
     eb = body.get("extra_body")
     assert isinstance(eb, dict)
     assert eb.get("metadata") == {"user": "u1"}
+    literal_extra_body = eb.get("extra_body")
+    assert isinstance(literal_extra_body, dict)
+    google = literal_extra_body.get("google")
+    assert isinstance(google, dict)
+
+
+def test_build_request_body_merges_caller_nested_google(gemini_provider):
+    req = MockRequest(
+        extra_body={
+            "metadata": {"user": "u1"},
+            "extra_body": {
+                "google": {
+                    "thinking_config": {"budget_tokens": 128},
+                    "cached_content": "cachedContents/example",
+                }
+            },
+        }
+    )
+
+    body = gemini_provider._build_request_body(req)
+
+    eb = body.get("extra_body")
+    assert isinstance(eb, dict)
+    assert eb.get("metadata") == {"user": "u1"}
+    literal_extra_body = eb.get("extra_body")
+    assert isinstance(literal_extra_body, dict)
+    google = literal_extra_body.get("google")
+    assert isinstance(google, dict)
+    assert google.get("cached_content") == "cachedContents/example"
+    thinking_config = google.get("thinking_config")
+    assert isinstance(thinking_config, dict)
+    assert thinking_config.get("budget_tokens") == 128
+    assert thinking_config.get("include_thoughts") is True
 
 
 @pytest.mark.asyncio