feat(provider): support native tools in API conversion

_convert_tools_to_anthropic now passes through native tool format
(bash_20250124, etc.) while still converting function tools.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

nanobot/providers/anthropic_oauth.py

@@ -201,19 +201,29 @@ class AnthropicOAuthProvider(LLMProvider):
         self,
         tools: list[dict[str, Any]] | None
     ) -> list[dict[str, Any]] | None:
-        """Convert OpenAI-format tools to Anthropic format."""
+        """Convert tools to Anthropic API format.
+
+        Supports both function tools (custom) and native tools (Anthropic).
+        Function tools are converted to Anthropic format.
+        Native tools are passed through unchanged.
+        """
         if not tools:
             return None
 
         anthropic_tools = []
         for tool in tools:
             if tool.get("type") == "function":
+                # Convert function tool format
                 func = tool["function"]
                 anthropic_tools.append({
                     "name": func["name"],
                     "description": func.get("description", ""),
                     "input_schema": func.get("parameters", {"type": "object", "properties": {}})
                 })
+            else:
+                # Pass through native tool format as-is
+                # (bash_20250124, text_editor_20250728, computer_20251124, etc.)
+                anthropic_tools.append(tool)
 
         return anthropic_tools if anthropic_tools else None
 

tests/test_anthropic_oauth_native_tools.py

@@ -0,0 +1,74 @@
+"""Tests for native tool support in AnthropicOAuthProvider."""
+
+from nanobot.providers.anthropic_oauth import AnthropicOAuthProvider
+
+
+def test_convert_tools_passes_through_native_tools():
+    """Test that native tool format is passed through unchanged."""
+    provider = AnthropicOAuthProvider(oauth_token="test", thinking_budget=0)
+
+    tools = [
+        {
+            "type": "bash_20250124",
+            "name": "bash"
+        }
+    ]
+
+    result = provider._convert_tools_to_anthropic(tools)
+    assert len(result) == 1
+    assert result[0]["type"] == "bash_20250124"
+    assert result[0]["name"] == "bash"
+
+
+def test_convert_tools_handles_mixed_tool_types():
+    """Test conversion of both function and native tools."""
+    provider = AnthropicOAuthProvider(oauth_token="test", thinking_budget=0)
+
+    tools = [
+        {
+            "type": "function",
+            "function": {
+                "name": "custom_tool",
+                "description": "A custom tool",
+                "parameters": {"type": "object", "properties": {"arg": {"type": "string"}}}
+            }
+        },
+        {
+            "type": "bash_20250124",
+            "name": "bash"
+        }
+    ]
+
+    result = provider._convert_tools_to_anthropic(tools)
+    assert len(result) == 2
+
+    # Function tool gets converted
+    assert result[0]["name"] == "custom_tool"
+    assert result[0]["description"] == "A custom tool"
+    assert "input_schema" in result[0]
+
+    # Native tool passed through
+    assert result[1]["type"] == "bash_20250124"
+    assert result[1]["name"] == "bash"
+
+
+def test_convert_tools_preserves_function_tool_conversion():
+    """Test that existing function tool conversion still works."""
+    provider = AnthropicOAuthProvider(oauth_token="test", thinking_budget=0)
+
+    tools = [
+        {
+            "type": "function",
+            "function": {
+                "name": "test",
+                "description": "desc",
+                "parameters": {"type": "object"}
+            }
+        }
+    ]
+
+    result = provider._convert_tools_to_anthropic(tools)
+    assert len(result) == 1
+    assert result[0]["name"] == "test"
+    assert result[0]["description"] == "desc"
+    assert result[0]["input_schema"] == {"type": "object"}