diff --git a/nanobot/providers/anthropic_provider.py b/nanobot/providers/anthropic_provider.py
index 8c43ce562..6e24b4ba4 100644
--- a/nanobot/providers/anthropic_provider.py
+++ b/nanobot/providers/anthropic_provider.py
@@ -614,9 +614,8 @@ class AnthropicProvider(LLMProvider):
             model_name, _THINKING_DISABLE_MIN_VERSIONS
         ):
             # These models think by default, so omission would not honor an
-            # explicit request to disable thinking. Use extra_body for SDKs
-            # that predate the typed thinking parameter.
-            kwargs["extra_body"] = {"thinking": {"type": "disabled"}}
+            # explicit request to disable thinking.
+            kwargs["thinking"] = {"type": "disabled"}
         elif reasoning_effort_lower == "adaptive":
             # Adaptive thinking: model decides when and how much to think
             # Also auto-enables interleaved thinking between tool calls.
@@ -626,13 +625,8 @@ class AnthropicProvider(LLMProvider):
         elif thinking_enabled and adaptive_only:
             # Newer Claude models removed manual token budgets. Their effort
             # control is independent from the adaptive thinking mode.
-            # These fields were added as first-class SDK arguments after our
-            # minimum anthropic version; extra_body preserves wire compatibility
-            # across the declared dependency range.
-            kwargs["extra_body"] = {
-                "thinking": {"type": "adaptive"},
-                "output_config": {"effort": reasoning_effort_lower},
-            }
+            kwargs["thinking"] = {"type": "adaptive"}
+            kwargs["output_config"] = {"effort": reasoning_effort_lower}
         elif thinking_enabled:
             budget_map = {"low": 1024, "medium": 4096, "high": max(8192, max_tokens)}
             budget = budget_map.get(reasoning_effort_lower, 4096)
diff --git a/pyproject.toml b/pyproject.toml
index d2be96b23..a4056afdf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,7 +24,7 @@ license-files = [
 
 dependencies = [
     "typer>=0.20.0,<1.0.0",
-    "anthropic>=0.45.0,<1.0.0",
+    "anthropic>=0.100.0,<1.0.0",
     "pydantic>=2.12.0,<3.0.0",
     "pydantic-settings>=2.12.0,<3.0.0",
     # Feishu's lark-oapi currently requires websockets<16; core supports 15 and 16.
diff --git a/tests/providers/test_anthropic_thinking.py b/tests/providers/test_anthropic_thinking.py
index 2e962175b..de5e9ffbe 100644
--- a/tests/providers/test_anthropic_thinking.py
+++ b/tests/providers/test_anthropic_thinking.py
@@ -82,8 +82,8 @@ def test_opus_4_7_omits_temperature_adaptive() -> None:
 def test_opus_4_7_high_uses_adaptive_effort() -> None:
     kw = _build(_make_provider("claude-opus-4-7"), "high", max_tokens=4096)
     assert "temperature" not in kw
-    assert kw["extra_body"]["thinking"] == {"type": "adaptive"}
-    assert kw["extra_body"]["output_config"] == {"effort": "high"}
+    assert kw["thinking"] == {"type": "adaptive"}
+    assert kw["output_config"] == {"effort": "high"}
     assert kw["max_tokens"] == 4096
 
 
@@ -102,8 +102,8 @@ def test_opus_4_8_omits_temperature_adaptive() -> None:
 def test_opus_4_8_high_uses_adaptive_effort() -> None:
     kw = _build(_make_provider("claude-opus-4-8"), "high", max_tokens=4096)
     assert "temperature" not in kw
-    assert kw["extra_body"]["thinking"] == {"type": "adaptive"}
-    assert kw["extra_body"]["output_config"] == {"effort": "high"}
+    assert kw["thinking"] == {"type": "adaptive"}
+    assert kw["output_config"] == {"effort": "high"}
 
 
 def test_opus_4_8_omits_temperature_none() -> None:
@@ -119,8 +119,8 @@ def test_fable_omits_temperature_adaptive() -> None:
 def test_fable_high_uses_adaptive_effort() -> None:
     kw = _build(_make_provider("claude-fable-5"), "high", max_tokens=4096)
     assert "temperature" not in kw
-    assert kw["extra_body"]["thinking"] == {"type": "adaptive"}
-    assert kw["extra_body"]["output_config"] == {"effort": "high"}
+    assert kw["thinking"] == {"type": "adaptive"}
+    assert kw["output_config"] == {"effort": "high"}
 
 
 def test_fable_omits_temperature_none() -> None:
@@ -137,22 +137,22 @@ def test_sonnet_5_omits_temperature_adaptive() -> None:
 def test_sonnet_5_high_uses_adaptive_effort() -> None:
     kw = _build(_make_provider("claude-sonnet-5"), "high", max_tokens=4096)
     assert "temperature" not in kw
-    assert kw["extra_body"]["thinking"] == {"type": "adaptive"}
-    assert kw["extra_body"]["output_config"] == {"effort": "high"}
+    assert kw["thinking"] == {"type": "adaptive"}
+    assert kw["output_config"] == {"effort": "high"}
 
 
 def test_sonnet_5_omits_temperature_none() -> None:
     kw = _build(_make_provider("anthropic/claude-sonnet-5"), "none")
     assert "temperature" not in kw
-    assert "thinking" not in kw
-    assert kw["extra_body"] == {"thinking": {"type": "disabled"}}
+    assert kw["thinking"] == {"type": "disabled"}
+    assert "output_config" not in kw
 
 
 def test_mythos_preview_omits_temperature_but_keeps_manual_budget() -> None:
     kw = _build(_make_provider("claude-mythos-preview"), "high", max_tokens=4096)
     assert "temperature" not in kw
     assert kw["thinking"] == {"type": "enabled", "budget_tokens": 8192}
-    assert "extra_body" not in kw
+    assert "output_config" not in kw
 
 
 @pytest.mark.parametrize(
@@ -165,36 +165,36 @@ def test_opus_5_omits_temperature(reasoning_effort: str | None) -> None:
 
 def test_opus_5_none_disables_default_thinking() -> None:
     kw = _build(_make_provider("claude-opus-5"), "none")
-    assert kw["extra_body"] == {"thinking": {"type": "disabled"}}
-    assert "thinking" not in kw
+    assert kw["thinking"] == {"type": "disabled"}
+    assert "output_config" not in kw
 
 
 def test_opus_5_unset_preserves_provider_default() -> None:
     kw = _build(_make_provider("claude-opus-5"), None)
     assert "thinking" not in kw
-    assert "extra_body" not in kw
+    assert "output_config" not in kw
 
 
 @pytest.mark.parametrize("reasoning_effort", ["low", "medium", "high", "xhigh", "max"])
 def test_opus_5_uses_adaptive_thinking_with_effort(reasoning_effort: str) -> None:
     kw = _build(_make_provider("claude-opus-5"), reasoning_effort, max_tokens=4096)
-    assert kw["extra_body"]["thinking"] == {"type": "adaptive"}
-    assert kw["extra_body"]["output_config"] == {"effort": reasoning_effort}
+    assert kw["thinking"] == {"type": "adaptive"}
+    assert kw["output_config"] == {"effort": reasoning_effort}
     assert kw["max_tokens"] == 4096
 
 
 def test_dated_opus_5_model_uses_family_capabilities() -> None:
     kw = _build(_make_provider("claude-opus-5-20260724"), "medium")
     assert "temperature" not in kw
-    assert kw["extra_body"]["thinking"] == {"type": "adaptive"}
-    assert kw["extra_body"]["output_config"] == {"effort": "medium"}
+    assert kw["thinking"] == {"type": "adaptive"}
+    assert kw["output_config"] == {"effort": "medium"}
 
 
 def test_dated_opus_4_model_does_not_treat_date_as_minor_version() -> None:
     kw = _build(_make_provider("claude-opus-4-20250514"), "high")
     assert kw["temperature"] == 1.0
     assert kw["thinking"] == {"type": "enabled", "budget_tokens": 8192}
-    assert "extra_body" not in kw
+    assert "output_config" not in kw
 
 
 def test_ordinary_model_sends_temperature() -> None: