refactor(caching): tighten anthropic messages cache types and drop comments

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/caching/caching_handler.py

@@ -18,6 +18,7 @@ import asyncio
 import datetime
 import inspect
 import time
+from collections.abc import AsyncIterator
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -1058,14 +1059,6 @@ class LLMCachingHandler:
         )
 
     def wrap_streaming_result_for_cache(self, result: Any, call_type: str) -> Any:
-        """
-        Tee a streaming result so it still reaches the cache.
-
-        Streaming responses are returned to the caller before ``async_set_cache``
-        runs. Chat/text completion streams are teed inside ``CustomStreamWrapper``
-        and Responses API streams inside their own iterator; Anthropic Messages
-        streams have no such hook, so they are wrapped here.
-        """
         if call_type not in (
             CallTypes.anthropic_messages.value,
             CallTypes.aanthropic_messages.value,
@@ -1075,7 +1068,7 @@ class LLMCachingHandler:
             original_function=self.original_function, kwargs=self.request_kwargs
         ):
             return result
-        if not hasattr(result, "__anext__"):
+        if not isinstance(result, AsyncIterator):
             return result
         from litellm.llms.anthropic.experimental_pass_through.messages.response_cache import (
             AnthropicMessagesStreamCacheWriter,

litellm/litellm_core_utils/model_param_helper.py

@@ -174,13 +174,8 @@ class ModelParamHelper:
     def _get_litellm_supported_anthropic_messages_kwargs() -> set[str]:
         """
         Get the litellm supported Anthropic /v1/messages kwargs
-
-        This follows the Anthropic Messages API spec. `system`, `top_k` and
-        `stop_sequences` have no OpenAI equivalent, so without them the cache key
-        for a /v1/messages request ignores them and collides across requests that
-        differ only by system prompt.
         """
-        return set(getattr(AnthropicMessagesRequest, "__annotations__", {}).keys())
+        return set(AnthropicMessagesRequest.__annotations__.keys())
 
     @staticmethod
     def _get_exclude_kwargs() -> Set[str]:

litellm/llms/anthropic/experimental_pass_through/messages/response_cache.py

@@ -1,13 +1,3 @@
-"""
-Response caching for Anthropic Messages (`/v1/messages`) requests.
-
-Non-streaming responses are plain dicts and are stored by the generic caching
-handler. Streaming responses are returned to the caller before
-``LLMCachingHandler.async_set_cache`` runs, so they are teed here instead: the
-SSE events are buffered while they are forwarded and persisted verbatim once the
-stream completes, and a hit replays exactly what the provider sent.
-"""
-
 from collections.abc import AsyncIterator
 from typing import TYPE_CHECKING, Any, cast
 
@@ -38,14 +28,6 @@ def _decode(chunk: bytes | str) -> str:
 
 
 class AnthropicMessagesStreamCacheWriter:
-    """
-    Forwards a `/v1/messages` SSE stream unchanged while buffering it, then
-    writes the collected events to the response cache on normal completion.
-
-    Only a stream that ran to a ``message_stop`` without a provider ``error``
-    event is written, so partial or failed responses cannot be replayed.
-    """
-
     def __init__(
         self,
         stream: AsyncIterator[bytes | str],
@@ -105,11 +87,6 @@ class AnthropicMessagesStreamCacheWriter:
 
 
 class CachedAnthropicMessagesStreamIterator(BaseAnthropicMessagesStreamingIterator):
-    """
-    Replays cached `/v1/messages` SSE events and logs the request as a cache hit
-    once the replay finishes, mirroring what the live stream logs at end of stream.
-    """
-
     def __init__(
         self,
         events: list[str],
@@ -146,11 +123,6 @@ def convert_cached_anthropic_messages_result(
     logging_obj: LiteLLMLoggingObj,
     kwargs: dict[str, Any],
 ) -> AnthropicMessagesResponse | CachedAnthropicMessagesStreamIterator:
-    """
-    Turn a cached `/v1/messages` entry back into what the caller expects: an
-    SSE replay iterator for a streamed entry, otherwise the response itself
-    (``AnthropicMessagesResponse`` is a TypedDict, i.e. a dict at runtime).
-    """
     events = get_cached_stream_events(cached_result)
     if events is not None:
         return CachedAnthropicMessagesStreamIterator(