diff --git a/app/converters/anthropic_to_bedrock.py b/app/converters/anthropic_to_bedrock.py
index a2e9c39..3f4473d 100644
--- a/app/converters/anthropic_to_bedrock.py
+++ b/app/converters/anthropic_to_bedrock.py
@@ -141,7 +141,7 @@ def convert_request(
                     additional_fields.update(thinking_config)
 
         # Add anthropic_beta features for Claude models (from client-provided headers)
-        # Rules loaded from DynamoDB (blocklist → filter, mapping → translate, else → passthrough)
+        # Rules loaded from DynamoDB (blocklist → filter, mapping → translate, else → drop)
         if self._is_claude_model() and anthropic_beta:
             from app.db.beta_header_cache import BetaHeaderConfigCache
             cache = BetaHeaderConfigCache.instance()
@@ -159,8 +159,8 @@ def convert_request(
                     bedrock_beta.extend(mapped)
                     print(f"[CONVERTER] Mapped beta header '{beta_value}' → {mapped}")
                 else:
-                    bedrock_beta.append(beta_value)
-                    print(f"[CONVERTER] Passing through beta header: {beta_value}")
+                    # Drop unknown beta flags — Bedrock rejects unrecognized Anthropic-specific values
+                    print(f"[CONVERTER] Dropping unknown beta header (not supported by Bedrock): {beta_value}")
 
             if bedrock_beta:
                 additional_fields["anthropic_beta"] = bedrock_beta
diff --git a/app/core/config.py b/app/core/config.py
index b891a0c..8e4f1bf 100644
--- a/app/core/config.py
+++ b/app/core/config.py
@@ -222,7 +222,13 @@ class Settings(BaseSettings):
         default=[
             "prompt-caching-scope-2026-01-05",
             "redact-thinking-2026-02-12",
-            "advisor-tool-2026-03-01"
+            "advisor-tool-2026-03-01",
+            # Claude Code client headers — Anthropic-specific, not supported by Bedrock
+            "claude-code-20250219",
+            "context-1m-2025-08-07",
+            "interleaved-thinking-2025-05-14",
+            "context-management-2025-06-27",
+            "effort-2025-11-24",
         ],
         alias="BETA_HEADERS_BLOCKLIST",
         description="Beta headers that should NOT be passed to Bedrock (unsupported)",
diff --git a/app/services/bedrock_service.py b/app/services/bedrock_service.py
index 95fee37..db75aca 100644
--- a/app/services/bedrock_service.py
+++ b/app/services/bedrock_service.py
@@ -510,13 +510,9 @@ def _convert_to_anthropic_native_request(
         if request.metadata:
             native_request["metadata"] = request.metadata.model_dump() if hasattr(request.metadata, "model_dump") else request.metadata
 
-        # Add output_config if present (e.g., effort level)
-        if request.output_config:
-            native_request["output_config"] = request.output_config
+        # output_config (effort level) is not supported by Bedrock — drop it
 
-        # Add context_management if present (e.g., compact-2026-01-12 beta)
-        if request.context_management:
-            native_request["context_management"] = request.context_management
+        # context_management (compact-2026-01-12 beta) is not supported by Bedrock — drop it
 
         # Auto-inject advanced-tool-use beta header if tools contain defer_loading
         # but the client didn't send the required beta header.
@@ -554,8 +550,8 @@ def _convert_to_anthropic_native_request(
                     bedrock_beta.extend(mapped)
                     print(f"[BEDROCK NATIVE] Mapped beta header '{beta_value}' → {mapped}")
                 else:
-                    bedrock_beta.append(beta_value)
-                    print(f"[BEDROCK NATIVE] Passing through beta header: {beta_value}")
+                    # Drop unknown beta flags — Bedrock rejects unrecognized Anthropic-specific values
+                    print(f"[BEDROCK NATIVE] Dropping unknown beta header (not supported by Bedrock): {beta_value}")
 
         if bedrock_beta:
             native_request["anthropic_beta"] = bedrock_beta