fix(bedrock/claude_platform): make unsupported-param list overridable

Add claude_platform_unsupported_params in litellm_params so operators
can clear or override the blocked-param set without a code change when
the AWS endpoint adds support. Also add mutation-safety assertions to
the messages-path tests per Greptile review feedback.

litellm/llms/bedrock/claude_platform/common_utils.py

@@ -14,7 +14,7 @@ CLAUDE_PLATFORM_BEDROCK_ROUTE = "claude_platform/"
 # must not be forwarded in the Messages API request body (together with any
 # key prefixed "aws_") — the API rejects unknown fields with
 # "Extra inputs are not permitted".
-CLAUDE_PLATFORM_NON_REQUEST_PARAMS = {
+CLAUDE_PLATFORM_ON_AWS_NON_REQUEST_PARAMS = {
     "workspace_id",
     "anthropic_workspace_id",
     "anthropic-workspace-id",
@@ -25,12 +25,15 @@ CLAUDE_PLATFORM_NON_REQUEST_PARAMS = {
 # endpoint, which rejects them with "Extra inputs are not permitted". Unlike
 # the auth params above these carry user intent, so dropping them is logged at
 # WARNING — the request succeeds but the requested feature is not applied.
-CLAUDE_PLATFORM_UNSUPPORTED_REQUEST_PARAMS = {
+CLAUDE_PLATFORM_ON_AWS_UNSUPPORTED_REQUEST_PARAMS = {
     "context_management",
 }
 
 
-def filter_claude_platform_request_body(params: dict) -> dict:
+def filter_claude_platform_request_body(
+    params: dict,
+    unsupported_override: Optional[frozenset[str]] = None,
+) -> dict:
     """Return a copy of ``params`` with fields the Claude Platform on AWS
     endpoint rejects removed.
 
@@ -41,15 +44,23 @@ def filter_claude_platform_request_body(params: dict) -> dict:
     WARNING, since those reflect user intent that will not be applied on this
     route.
 
+    ``unsupported_override``, when provided, replaces the default
+    CLAUDE_PLATFORM_ON_AWS_UNSUPPORTED_REQUEST_PARAMS set. Pass an empty frozenset
+    to disable unsupported-param filtering entirely (e.g. when the AWS
+    endpoint adds support before a litellm release).
+
     Filters a copy so callers' ``sign_request`` still sees ``aws_region_name``.
     """
-    dropped_unsupported = [
-        k for k in params if k in CLAUDE_PLATFORM_UNSUPPORTED_REQUEST_PARAMS
-    ]
+    unsupported = (
+        unsupported_override
+        if unsupported_override is not None
+        else CLAUDE_PLATFORM_ON_AWS_UNSUPPORTED_REQUEST_PARAMS
+    )
+    dropped_unsupported = [k for k in params if k in unsupported]
     if dropped_unsupported:
         verbose_logger.warning(
             "bedrock/claude_platform: dropping unsupported Messages API "
-            "param(s) %s from the request body — the Claude Platform on AWS "
+            "param(s) %s from the request body - the Claude Platform on AWS "
             "(aws-external-anthropic) endpoint does not support them and "
             "rejects unknown fields. The request will proceed without them.",
             dropped_unsupported,
@@ -57,12 +68,29 @@ def filter_claude_platform_request_body(params: dict) -> dict:
     return {
         k: v
         for k, v in params.items()
-        if k not in CLAUDE_PLATFORM_NON_REQUEST_PARAMS
-        and k not in CLAUDE_PLATFORM_UNSUPPORTED_REQUEST_PARAMS
+        if k not in CLAUDE_PLATFORM_ON_AWS_NON_REQUEST_PARAMS
+        and k not in unsupported
         and not k.startswith("aws_")
     }
 
 
+def _resolve_unsupported_override(
+    litellm_params: dict,
+) -> Optional[frozenset[str]]:
+    """Read ``claude_platform_unsupported_params`` from litellm_params.
+
+    Returns None (use default set) when the key is absent. Returns a
+    frozenset when present, allowing operators to override or clear the
+    unsupported-param list via proxy config without a code change.
+    """
+    raw = litellm_params.get("claude_platform_unsupported_params")
+    if raw is None:
+        return None
+    if isinstance(raw, (list, set, frozenset, tuple)):
+        return frozenset(raw)
+    return None
+
+
 def strip_claude_platform_route(model: str) -> str:
     if model.startswith(CLAUDE_PLATFORM_BEDROCK_ROUTE):
         return model.replace(CLAUDE_PLATFORM_BEDROCK_ROUTE, "", 1)

litellm/llms/bedrock/claude_platform/messages_transformation.py

@@ -10,6 +10,7 @@ from litellm.types.router import GenericLiteLLMParams
 
 from .common_utils import (
     BedrockClaudePlatformMixin,
+    _resolve_unsupported_override,
     filter_claude_platform_request_body,
     strip_claude_platform_route,
 )
@@ -66,13 +67,11 @@ class BedrockClaudePlatformMessagesConfig(
         litellm_params: GenericLiteLLMParams,
         headers: dict,
     ) -> Dict:
-        # Strip auth/routing config (workspace_id, aws_*) and Messages API
-        # fields the AWS endpoint does not support (e.g. context_management)
-        # from the body — the API rejects unknown fields with "Extra inputs
-        # are not permitted".
+        unsupported_override = _resolve_unsupported_override(litellm_params)
         anthropic_messages_optional_request_params = (
             filter_claude_platform_request_body(
-                anthropic_messages_optional_request_params
+                anthropic_messages_optional_request_params,
+                unsupported_override=unsupported_override,
             )
         )
         return super().transform_anthropic_messages_request(

litellm/llms/bedrock/claude_platform/transformation.py

@@ -7,6 +7,7 @@ from litellm.types.llms.openai import AllMessageValues
 
 from .common_utils import (
     BedrockClaudePlatformMixin,
+    _resolve_unsupported_override,
     filter_claude_platform_request_body,
 )
 
@@ -93,12 +94,10 @@ class BedrockClaudePlatformConfig(BedrockClaudePlatformMixin, AnthropicConfig):
         litellm_params: dict,
         headers: dict,
     ) -> dict:
-        # Strip auth/routing config (workspace_id, aws_*) and Messages API
-        # fields the AWS endpoint does not support (e.g. context_management)
-        # from the body — the API rejects unknown fields with "Extra inputs
-        # are not permitted". Filters a copy so sign_request still sees
-        # aws_region_name.
-        optional_params = filter_claude_platform_request_body(optional_params)
+        unsupported_override = _resolve_unsupported_override(litellm_params)
+        optional_params = filter_claude_platform_request_body(
+            optional_params, unsupported_override=unsupported_override
+        )
         return super().transform_request(
             model=model,
             messages=messages,

tests/test_litellm/llms/bedrock/test_claude_platform_provider.py

@@ -361,14 +361,15 @@ def test_claude_platform_messages_strips_auth_params_from_request_body():
     )
     assert config is not None
 
+    input_params = {
+        "workspace_id": "wrkspc_test",
+        "aws_region_name": "us-west-2",
+        "max_tokens": 10,
+    }
     request_body = config.transform_anthropic_messages_request(
         model="claude_platform/claude-sonnet-4-6",
         messages=[{"role": "user", "content": "hello"}],
-        anthropic_messages_optional_request_params={
-            "workspace_id": "wrkspc_test",
-            "aws_region_name": "us-west-2",
-            "max_tokens": 10,
-        },
+        anthropic_messages_optional_request_params=input_params,
         litellm_params={},
         headers={},
     )
@@ -376,6 +377,8 @@ def test_claude_platform_messages_strips_auth_params_from_request_body():
     assert "workspace_id" not in request_body
     assert "aws_region_name" not in request_body
     assert request_body["max_tokens"] == 10
+    assert input_params["aws_region_name"] == "us-west-2"
+    assert input_params["workspace_id"] == "wrkspc_test"
 
 
 def test_claude_platform_strips_unsupported_context_management_param(caplog):
@@ -433,19 +436,48 @@ def test_claude_platform_messages_strips_unsupported_context_management_param():
     )
     assert config is not None
 
+    input_params = {
+        "context_management": {"edits": [{"type": "clear_tool_uses_20250919"}]},
+        "max_tokens": 10,
+    }
     request_body = config.transform_anthropic_messages_request(
         model="claude_platform/claude-sonnet-4-6",
         messages=[{"role": "user", "content": "hello"}],
-        anthropic_messages_optional_request_params={
-            "context_management": {"edits": [{"type": "clear_tool_uses_20250919"}]},
-            "max_tokens": 10,
-        },
+        anthropic_messages_optional_request_params=input_params,
         litellm_params={},
         headers={},
     )
 
     assert "context_management" not in request_body
     assert request_body["max_tokens"] == 10
+    assert "context_management" in input_params
+
+
+def test_claude_platform_unsupported_override_allows_context_management():
+    """
+    Operators can pass claude_platform_unsupported_params=[] in litellm_params
+    to stop filtering context_management once the AWS endpoint supports it.
+    """
+    from litellm.llms.bedrock.claude_platform.transformation import (
+        BedrockClaudePlatformConfig,
+    )
+
+    config = BedrockClaudePlatformConfig()
+    optional_params = {
+        "context_management": {"edits": [{"type": "clear_tool_uses_20250919"}]},
+        "max_tokens": 10,
+    }
+
+    request_body = config.transform_request(
+        model="claude-sonnet-4-6",
+        messages=[{"role": "user", "content": "hello"}],
+        optional_params=optional_params,
+        litellm_params={"claude_platform_unsupported_params": []},
+        headers={},
+    )
+
+    assert request_body["max_tokens"] == 10
+    assert "context_management" in request_body
 
 
 def test_chat_completion_claude_platform_sigv4_body_has_no_auth_params():