fix: handle LangGraph interrupts in human tool

Co-Authored-By: Joe Moura <joao@crewai.com>

src/crewai/tools/__init__.py

@@ -1 +1,2 @@
 from .base_tool import BaseTool, tool
+from .human_tool import HumanTool

src/crewai/tools/human_tool.py

@@ -0,0 +1,35 @@
+"""Tool for handling human input using LangGraph's interrupt mechanism."""
+
+from typing import Any, Dict
+from pydantic import Field
+
+from crewai.tools import BaseTool
+
+class HumanTool(BaseTool):
+    """Tool for getting human input using LangGraph's interrupt mechanism."""
+    
+    name: str = "human"
+    description: str = "Useful to ask user to enter input."
+    result_as_answer: bool = False  # Don't use the response as final answer
+
+    def _run(self, query: str) -> str:
+        """Execute the human input tool.
+        
+        Args:
+            query: The question to ask the user
+            
+        Returns:
+            The user's response
+            
+        Raises:
+            ImportError: If LangGraph is not installed
+        """
+        try:
+            from langgraph.prebuilt.state_graphs import interrupt
+            human_response = interrupt({"query": query})
+            return human_response["data"]
+        except ImportError:
+            raise ImportError(
+                "LangGraph is required for HumanTool. "
+                "Install with `pip install langgraph`"
+            )

src/crewai/tools/tool_usage.py

@@ -182,6 +182,10 @@ class ToolUsage:
                 else:
                     result = tool.invoke(input={})
             except Exception as e:
+                # Check if this is a LangGraph interrupt that should be propagated
+                if hasattr(e, '__class__') and e.__class__.__name__ == 'Interrupt':
+                    raise e  # Propagate interrupt up
+
                 self.on_tool_error(tool=tool, tool_calling=calling, e=e)
                 self._run_attempts += 1
                 if self._run_attempts > self._max_parsing_attempts:

tests/tools/test_human_tool.py

@@ -0,0 +1,42 @@
+"""Test HumanTool functionality."""
+
+import pytest
+from unittest.mock import patch
+
+from crewai.tools import HumanTool
+
+def test_human_tool_basic():
+    """Test basic HumanTool creation and attributes."""
+    tool = HumanTool()
+    assert tool.name == "human"
+    assert "ask user to enter input" in tool.description.lower()
+    assert not tool.result_as_answer
+
+@pytest.mark.vcr(filter_headers=["authorization"])
+def test_human_tool_with_langgraph_interrupt():
+    """Test HumanTool with LangGraph interrupt handling."""
+    tool = HumanTool()
+    
+    # Test successful interrupt handling
+    with patch('langgraph.prebuilt.state_graphs.interrupt') as mock_interrupt:
+        mock_interrupt.return_value = {"data": "test response"}
+        result = tool._run("test query")
+        assert result == "test response"
+        mock_interrupt.assert_called_with({"query": "test query"})
+
+    # Test interrupt propagation
+    with patch('langgraph.prebuilt.state_graphs.interrupt') as mock_interrupt:
+        mock_interrupt.side_effect = Exception("Interrupt")
+        with pytest.raises(Exception) as exc_info:
+            tool._run("test query")
+        assert "Interrupt" in str(exc_info.value)
+
+def test_human_tool_without_langgraph():
+    """Test HumanTool behavior when LangGraph is not installed."""
+    tool = HumanTool()
+    
+    with patch.dict('sys.modules', {'langgraph': None}):
+        with pytest.raises(ImportError) as exc_info:
+            tool._run("test query")
+        assert "LangGraph is required" in str(exc_info.value)
+        assert "pip install langgraph" in str(exc_info.value)

tests/tools/test_tool_usage.py

@@ -85,6 +85,38 @@ def test_random_number_tool_schema():
     )
 
 
+def test_tool_usage_interrupt_handling():
+    """Test that tool usage properly propagates LangGraph interrupts."""
+    from unittest.mock import patch, MagicMock
+
+    class InterruptingTool(BaseTool):
+        name: str = "interrupt_test"
+        description: str = "A tool that raises LangGraph interrupts"
+
+        def _run(self, query: str) -> str:
+            raise type('Interrupt', (Exception,), {})("test interrupt")
+
+    tool = InterruptingTool()
+    tool_usage = ToolUsage(
+        tools_handler=MagicMock(),
+        tools=[tool],
+        original_tools=[tool],
+        tools_description="Sample tool for testing",
+        tools_names="interrupt_test",
+        task=MagicMock(),
+        function_calling_llm=MagicMock(),
+        agent=MagicMock(),
+        action=MagicMock(),
+    )
+
+    # Test that interrupt is propagated
+    with pytest.raises(Exception) as exc_info:
+        tool_usage.use(
+            ToolCalling(tool_name="interrupt_test", arguments={"query": "test"}, log="test"),
+            "test"
+        )
+    assert "test interrupt" in str(exc_info.value)
+
 def test_tool_usage_render():
     tool = RandomNumberTool()