diff --git a/agent/utils/model.py b/agent/utils/model.py
index d007a66b..6fc469d4 100644
--- a/agent/utils/model.py
+++ b/agent/utils/model.py
@@ -184,13 +184,18 @@ def provider_model_kwargs(
         if effort is not None:
             kwargs["effort"] = effort
     elif model_id.startswith("bedrock_converse:"):
-        budget = {"low": 4000, "medium": 8000, "high": 16000, "xhigh": 32000, "max": 60000}.get(
-            profile_effort or ""
-        )
-        if budget is not None:
-            kwargs["additional_model_request_fields"] = {
-                "thinking": {"type": "enabled", "budget_tokens": budget}
-            }
+        # Opus 4.7+ on Bedrock rejects thinking.type "enabled"/budget_tokens with a
+        # ValidationException; it requires adaptive thinking plus output_config.effort,
+        # passed through Converse's additional_model_request_fields.
+        fields: dict[str, object] = {}
+        thinking = anthropic_thinking_for(profile_effort)
+        if thinking is not None:
+            fields["thinking"] = thinking
+        effort = anthropic_effort_for(profile_effort)
+        if effort is not None:
+            fields["output_config"] = {"effort": effort}
+        if fields:
+            kwargs["additional_model_request_fields"] = fields
     elif model_id.startswith("google_genai:") and is_gemini_3_family(model_id):
         thinking_level = google_thinking_level_for(profile_effort)
         if thinking_level is not None:
diff --git a/tests/test_agent_subagent_models.py b/tests/test_agent_subagent_models.py
index 73c4aaae..7d317f88 100644
--- a/tests/test_agent_subagent_models.py
+++ b/tests/test_agent_subagent_models.py
@@ -81,7 +81,8 @@ async def test_agent_uses_profile_subagent_model_override() -> None:
     main_call = make_model.call_args_list[0]
     assert main_call.args == ("bedrock_converse:us.anthropic.claude-opus-4-8",)
     assert main_call.kwargs["additional_model_request_fields"] == {
-        "thinking": {"type": "enabled", "budget_tokens": 16000}
+        "thinking": {"type": "adaptive", "display": "summarized"},
+        "output_config": {"effort": "high"},
     }
 
     subagent_call = make_model.call_args_list[1]
@@ -153,5 +154,6 @@ async def test_agent_subagent_inherits_profile_model_override_without_explicit_p
     assert make_model.call_args_list[0].args == ("bedrock_converse:us.anthropic.claude-opus-4-8",)
     assert make_model.call_args_list[1].args == ("bedrock_converse:us.anthropic.claude-opus-4-8",)
     assert make_model.call_args_list[1].kwargs["additional_model_request_fields"] == {
-        "thinking": {"type": "enabled", "budget_tokens": 16000}
+        "thinking": {"type": "adaptive", "display": "summarized"},
+        "output_config": {"effort": "high"},
     }