Update custom handoff tool doc (#211)

Closes
#199

Thank you for raising the issue! It does look like the example was
missing it.

Author: hinthornw

.gitignore

@@ -1,5 +1,6 @@
 # Pyenv
 .python-version
+.ipynb_checkpoints/
 
 # Byte-compiled / optimized / DLL files
 __pycache__/

Makefile

@@ -28,7 +28,7 @@ lint_diff format_diff: PYTHON_FILES=$(shell git diff --relative=. --name-only --
 lint lint_diff:
 	[ "$(PYTHON_FILES)" = "" ] ||	uv run ruff format $(PYTHON_FILES) --diff
 	[ "$(PYTHON_FILES)" = "" ] ||	uv run ruff check $(PYTHON_FILES) --diff
-	[ "$(PYTHON_FILES)" = "" ] || uv run mypy $(PYTHON_FILES)
+	[ "$(PYTHON_FILES)" = "" ] || uvx ty check $(PYTHON_FILES)
 
 format format_diff:
 	[ "$(PYTHON_FILES)" = "" ] || uv run ruff check --fix $(PYTHON_FILES)

README.md

@@ -229,6 +229,7 @@ from langchain_core.tools import tool, BaseTool, InjectedToolCallId
 from langchain_core.messages import ToolMessage
 from langgraph.types import Command
 from langgraph.prebuilt import InjectedState
+from langgraph_supervisor.handoff import METADATA_KEY_HANDOFF_DESTINATION
 
 def create_custom_handoff_tool(*, agent_name: str, name: str | None, description: str | None) -> BaseTool:
 
@@ -261,6 +262,7 @@ def create_custom_handoff_tool(*, agent_name: str, name: str | None, description
             },
         )
 
+    handoff_to_agent.metadata = {METADATA_KEY_HANDOFF_DESTINATION: agent_name}
     return handoff_to_agent
 ```
 

langgraph_supervisor/supervisor.py

@@ -57,7 +57,7 @@ def _supports_disable_parallel_tool_calls(model: LanguageModelLike) -> bool:
 
 
 def _make_call_agent(
-    agent: Pregel,
+    agent: Pregel[Any],
     output_mode: OutputMode,
     add_handoff_back_messages: bool,
     supervisor_name: str,
@@ -181,7 +181,7 @@ def _prepare_tool_node(
         if input_tool_node is not None:
             tool_node = ToolNode(
                 all_tools,
-                name=input_tool_node.name,
+                name=str(input_tool_node.name),
                 tags=list(input_tool_node.tags) if input_tool_node.tags else None,
                 handle_tool_errors=input_tool_node.handle_tool_errors,
                 messages_key=input_tool_node.messages_key,

pyproject.toml

@@ -60,3 +60,10 @@ warn_return_any = true
 warn_unused_configs = true
 disallow_untyped_defs = true
 check_untyped_defs = true
+
+[tool.ty.rules]
+no-matching-overload = "ignore" 
+call-non-callable = "ignore"
+unresolved-import = "ignore"
+[tool.ty.src]
+exclude = ["tests"]

tests/test_supervisor.py

@@ -1,4 +1,5 @@
 """Tests for the supervisor module."""
+# mypy: ignore-errors
 
 from collections.abc import Callable, Sequence
 from typing import Any, Optional, cast

tests/test_supervisor_functional_api.py

@@ -1,4 +1,5 @@
 """Tests for the supervisor module using functional API."""
+# mypy: ignore-errors
 
 from typing import Any, Dict, List