Fix serializability of ModelRequestParameters (#1690)

Author: dmontagu

pydantic_ai_slim/pydantic_ai/models/__init__.py

@@ -12,7 +12,6 @@
 from dataclasses import dataclass, field
 from datetime import datetime
 from functools import cache
-from typing import TYPE_CHECKING
 
 import httpx
 from typing_extensions import Literal, TypeAliasType
@@ -21,12 +20,9 @@
 from ..exceptions import UserError
 from ..messages import ModelMessage, ModelRequest, ModelResponse, ModelResponseStreamEvent
 from ..settings import ModelSettings
+from ..tools import ToolDefinition
 from ..usage import Usage
 
-if TYPE_CHECKING:
-    from ..tools import ToolDefinition
-
-
 KnownModelName = TypeAliasType(
     'KnownModelName',
     Literal[

tests/models/test_model_request_parameters.py

@@ -0,0 +1,12 @@
+from pydantic import TypeAdapter
+
+from pydantic_ai.models import ModelRequestParameters
+
+
+def test_model_request_parameters_are_serializable():
+    params = ModelRequestParameters(function_tools=[], allow_text_output=False, output_tools=[])
+    assert TypeAdapter(ModelRequestParameters).dump_python(params) == {
+        'function_tools': [],
+        'allow_text_output': False,
+        'output_tools': [],
+    }