fix: support Gemini JSON schema tools (#463)

* fix: support Gemini JSON schema tools

* fix: harden Dograh Gemini adapter wiring

* fix: route Gemini Live tool schemas through parameters_json_schema

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Abhishek Kumar <abhishek@a6k.me>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

api/tests/test_gemini_json_schema_adapter.py

@@ -0,0 +1,160 @@
+from unittest.mock import patch
+
+from google.genai.types import GenerateContentConfig, LiveConnectConfig
+from pipecat.adapters.schemas.function_schema import FunctionSchema
+from pipecat.adapters.schemas.tools_schema import ToolsSchema
+
+from api.services.configuration.registry import ServiceProviders
+from api.services.pipecat.gemini_json_schema_adapter import (
+    DograhGeminiJSONSchemaAdapter,
+)
+from api.services.pipecat.realtime.gemini_live import DograhGeminiLiveLLMService
+from api.services.pipecat.realtime.gemini_live_vertex import (
+    DograhGeminiLiveVertexLLMService,
+)
+from api.services.pipecat.service_factory import (
+    DograhGoogleLLMService,
+    DograhGoogleVertexLLMService,
+    create_llm_service_from_provider,
+)
+
+
+def test_gemini_tools_use_json_schema_parameters_for_external_schemas():
+    function_schema = FunctionSchema(
+        name="customer_lookup",
+        description="Look up a customer by email.",
+        properties={
+            "customerEmail": {
+                "description": "Customer email address",
+                "anyOf": [
+                    {"anyOf": [{"not": {}}]},
+                    {"const": ""},
+                ],
+            },
+            "metadata": {
+                "type": "object",
+                "additionalProperties": {"type": "string"},
+            },
+        },
+        required=["customerEmail"],
+    )
+
+    tools = DograhGeminiJSONSchemaAdapter().to_provider_tools_format(
+        ToolsSchema(standard_tools=[function_schema])
+    )
+
+    declaration = tools[0]["function_declarations"][0]
+    assert "parameters" not in declaration
+    assert (
+        declaration["parameters_json_schema"]["properties"]["customerEmail"]["anyOf"][
+            0
+        ]["anyOf"][0]["not"]
+        == {}
+    )
+    assert (
+        declaration["parameters_json_schema"]["properties"]["customerEmail"]["anyOf"][
+            1
+        ]["const"]
+        == ""
+    )
+    assert declaration["parameters_json_schema"]["properties"]["metadata"][
+        "additionalProperties"
+    ] == {"type": "string"}
+
+    GenerateContentConfig(tools=tools)
+
+
+def test_gemini_tools_use_json_schema_parameters_for_no_argument_tools():
+    function_schema = FunctionSchema(
+        name="refresh_context",
+        description="Refresh the current context.",
+        properties={},
+        required=[],
+    )
+
+    tools = DograhGeminiJSONSchemaAdapter().to_provider_tools_format(
+        ToolsSchema(standard_tools=[function_schema])
+    )
+
+    declaration = tools[0]["function_declarations"][0]
+    assert "parameters" not in declaration
+    assert declaration["parameters_json_schema"] == {
+        "type": "object",
+        "properties": {},
+        "required": [],
+    }
+
+    GenerateContentConfig(tools=tools)
+
+
+def test_google_service_classes_use_dograh_gemini_adapter_class():
+    assert DograhGoogleLLMService.adapter_class is DograhGeminiJSONSchemaAdapter
+    assert DograhGoogleVertexLLMService.adapter_class is DograhGeminiJSONSchemaAdapter
+
+
+def test_google_llm_service_factory_uses_dograh_service_class():
+    with patch(
+        "api.services.pipecat.service_factory.DograhGoogleLLMService",
+    ) as mock_service:
+        result = create_llm_service_from_provider(
+            provider=ServiceProviders.GOOGLE.value,
+            model="gemini-2.5-flash",
+            api_key="test-api-key",
+        )
+
+    assert result is mock_service.return_value
+    assert mock_service.call_args.kwargs["api_key"] == "test-api-key"
+    assert mock_service.call_args.kwargs["settings"].model == "gemini-2.5-flash"
+
+
+def test_google_vertex_llm_service_factory_uses_dograh_service_class():
+    with patch(
+        "api.services.pipecat.service_factory.DograhGoogleVertexLLMService",
+    ) as mock_service:
+        result = create_llm_service_from_provider(
+            provider=ServiceProviders.GOOGLE_VERTEX.value,
+            model="gemini-2.5-pro",
+            api_key=None,
+            project_id="demo-project",
+            location="us-central1",
+            credentials='{"type":"service_account"}',
+        )
+
+    assert result is mock_service.return_value
+    assert mock_service.call_args.kwargs["project_id"] == "demo-project"
+    assert mock_service.call_args.kwargs["location"] == "us-central1"
+    assert mock_service.call_args.kwargs["settings"].model == "gemini-2.5-pro"
+
+
+def test_gemini_live_service_classes_use_dograh_gemini_adapter_class():
+    assert DograhGeminiLiveLLMService.adapter_class is DograhGeminiJSONSchemaAdapter
+    # Vertex Live inherits adapter_class from DograhGeminiLiveLLMService via MRO.
+    assert (
+        DograhGeminiLiveVertexLLMService.adapter_class is DograhGeminiJSONSchemaAdapter
+    )
+
+
+def test_gemini_live_config_accepts_json_schema_tools():
+    function_schema = FunctionSchema(
+        name="customer_lookup",
+        description="Look up a customer by email.",
+        properties={
+            "customerEmail": {
+                "description": "Customer email address",
+                "anyOf": [{"not": {}}, {"const": ""}],
+            },
+        },
+        required=["customerEmail"],
+    )
+
+    tools = DograhGeminiJSONSchemaAdapter().to_provider_tools_format(
+        ToolsSchema(standard_tools=[function_schema])
+    )
+
+    declaration = tools[0]["function_declarations"][0]
+    assert "parameters" not in declaration
+    assert "parameters_json_schema" in declaration
+
+    # Gemini Live validates tools through LiveConnectConfig rather than
+    # GenerateContentConfig; it must also accept the raw JSON Schema payload.
+    LiveConnectConfig(tools=tools)

api/tests/test_google_vertex_llm_service_factory.py

@@ -34,7 +34,7 @@ class TestGoogleVertexLLMConfiguration:
 class TestGoogleVertexLLMServiceFactory:
     def test_create_llm_service_from_provider_uses_vertex_service(self):
         with patch(
-            "api.services.pipecat.service_factory.GoogleVertexLLMService"
+            "api.services.pipecat.service_factory.DograhGoogleVertexLLMService"
         ) as mock_service:
             create_llm_service_from_provider(
                 provider=ServiceProviders.GOOGLE_VERTEX.value,
@@ -65,7 +65,7 @@ class TestGoogleVertexLLMServiceFactory:
         )
 
         with patch(
-            "api.services.pipecat.service_factory.GoogleVertexLLMService"
+            "api.services.pipecat.service_factory.DograhGoogleVertexLLMService"
         ) as mock_service:
             create_llm_service(user_config)