Add prompt caching options to OpenAIChatModelSettings (#3678)

Author: kichanyurd

pydantic_ai_slim/pydantic_ai/models/openai.py

@@ -231,6 +231,18 @@ class OpenAIChatModelSettings(ModelSettings, total=False):
     This feature is currently only supported for some OpenAI models.
     """
 
+    openai_prompt_cache_key: str
+    """Used by OpenAI to cache responses for similar requests to optimize your cache hit rates.
+
+    See the [OpenAI Prompt Caching documentation](https://platform.openai.com/docs/guides/prompt-caching#how-it-works) for more information.
+    """
+
+    openai_prompt_cache_retention: Literal['in-memory', '24h']
+    """The retention policy for the prompt cache. Set to 24h to enable extended prompt caching, which keeps cached prefixes active for longer, up to a maximum of 24 hours.
+
+    See the [OpenAI Prompt Caching documentation](https://platform.openai.com/docs/guides/prompt-caching#how-it-works) for more information.
+    """
+
 
 @deprecated('Use `OpenAIChatModelSettings` instead.')
 class OpenAIModelSettings(OpenAIChatModelSettings, total=False):
@@ -580,6 +592,8 @@ async def _completions_create(
                 logit_bias=model_settings.get('logit_bias', OMIT),
                 logprobs=model_settings.get('openai_logprobs', OMIT),
                 top_logprobs=model_settings.get('openai_top_logprobs', OMIT),
+                prompt_cache_key=model_settings.get('openai_prompt_cache_key', OMIT),
+                prompt_cache_retention=model_settings.get('openai_prompt_cache_retention', OMIT),
                 extra_headers=extra_headers,
                 extra_body=model_settings.get('extra_body'),
             )
@@ -1423,6 +1437,8 @@ async def _responses_create(  # noqa: C901
                 user=model_settings.get('openai_user', OMIT),
                 text=text or OMIT,
                 include=include or OMIT,
+                prompt_cache_key=model_settings.get('openai_prompt_cache_key', OMIT),
+                prompt_cache_retention=model_settings.get('openai_prompt_cache_retention', OMIT),
                 extra_headers=extra_headers,
                 extra_body=model_settings.get('extra_body'),
             )