fix(anthropic): auto-inject compact beta header for context_management

get_anthropic_beta_list() did not detect context_management in
optional_params, so Bedrock InvokeModel requests with compaction
never received the required "compact-2026-01-12" in anthropic_beta.
Bedrock rejects context_management without the beta header with
"Extra inputs are not permitted".

The direct Anthropic path already handled this via
_ensure_context_management_beta_header (HTTP headers), but the
Bedrock path builds its beta list from get_anthropic_beta_list()
which feeds the request body's anthropic_beta array.

Fixes #27532

litellm/llms/anthropic/common_utils.py

@@ -14,6 +14,7 @@ from litellm.litellm_core_utils.prompt_templates.common_utils import (
 from litellm.llms.base_llm.base_utils import BaseLLMModelInfo, BaseTokenCounter
 from litellm.llms.base_llm.chat.transformation import BaseLLMException
 from litellm.types.llms.anthropic import (
+    ANTHROPIC_BETA_HEADER_VALUES,
     ANTHROPIC_HOSTED_TOOLS,
     ANTHROPIC_OAUTH_BETA_HEADER,
     ANTHROPIC_OAUTH_TOKEN_PREFIX,
@@ -417,6 +418,20 @@ class AnthropicModelInfo(BaseLLMModelInfo):
         if mcp_server_used:
             betas.append("mcp-client-2025-04-04")
 
+        if optional_params:
+            context_management = optional_params.get("context_management")
+            if isinstance(context_management, dict) and "edits" in context_management:
+                for edit in context_management.get("edits", []):
+                    edit_type = edit.get("type", "")
+                    if edit_type in ("compact_20260112", "compaction"):
+                        betas.append(
+                            ANTHROPIC_BETA_HEADER_VALUES.COMPACT_2026_01_12.value
+                        )
+                    else:
+                        betas.append(
+                            ANTHROPIC_BETA_HEADER_VALUES.CONTEXT_MANAGEMENT_2025_06_27.value
+                        )
+
         return list(set(betas))
 
     def get_anthropic_headers(

tests/test_litellm/llms/anthropic/test_anthropic_common_utils.py

@@ -1280,3 +1280,51 @@ class TestAnthropicThinkingSignatureSelfHeal:
         config.transform_anthropic_messages_request_on_http_error(err, data)
         assert "thinking" not in data
         assert data["messages"] == []
+
+
+class TestGetAnthropicBetaListContextManagement:
+    """
+    Regression tests for https://github.com/BerriAI/litellm/issues/27532
+    get_anthropic_beta_list must include compact/context-management betas
+    when context_management is in optional_params, so Bedrock InvokeModel
+    receives the required anthropic_beta field.
+    """
+
+    def test_compact_edit_adds_compact_beta(self):
+        from litellm.llms.anthropic.common_utils import AnthropicModelInfo
+
+        info = AnthropicModelInfo()
+        betas = info.get_anthropic_beta_list(
+            model="claude-sonnet-4-6",
+            optional_params={
+                "context_management": {
+                    "edits": [{"type": "compact_20260112"}],
+                }
+            },
+        )
+        assert "compact-2026-01-12" in betas
+
+    def test_non_compact_edit_adds_context_management_beta(self):
+        from litellm.llms.anthropic.common_utils import AnthropicModelInfo
+
+        info = AnthropicModelInfo()
+        betas = info.get_anthropic_beta_list(
+            model="claude-sonnet-4-6",
+            optional_params={
+                "context_management": {
+                    "edits": [{"type": "summarize"}],
+                }
+            },
+        )
+        assert "context-management-2025-06-27" in betas
+
+    def test_no_context_management_no_extra_betas(self):
+        from litellm.llms.anthropic.common_utils import AnthropicModelInfo
+
+        info = AnthropicModelInfo()
+        betas = info.get_anthropic_beta_list(
+            model="claude-sonnet-4-6",
+            optional_params={"max_tokens": 100},
+        )
+        assert "compact-2026-01-12" not in betas
+        assert "context-management-2025-06-27" not in betas