chore: import upstream snapshot with attribution

examples/integrations/agentcore/agents/langgraph-single-agent/tools/__init__.py

@@ -0,0 +1,8 @@
+# patterns/langgraph-single-agent/tools/__init__.py
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+from .query_data import query_data
+from .todos import AgentState, todo_tools
+
+__all__ = ["query_data", "AgentState", "todo_tools"]

examples/integrations/agentcore/agents/langgraph-single-agent/tools/db.csv

@@ -0,0 +1,16 @@
+date,category,amount,type
+2026-01-05,Food,42.50,expense
+2026-01-10,Transport,15.00,expense
+2026-01-15,Salary,3500.00,income
+2026-01-20,Entertainment,80.00,expense
+2026-01-25,Utilities,120.00,expense
+2026-02-03,Food,55.20,expense
+2026-02-08,Freelance,800.00,income
+2026-02-14,Dining,65.00,expense
+2026-02-20,Transport,22.50,expense
+2026-02-28,Salary,3500.00,income
+2026-03-05,Groceries,95.40,expense
+2026-03-10,Gym,40.00,expense
+2026-03-15,Salary,3500.00,income
+2026-03-18,Coffee,18.75,expense
+2026-03-22,Books,35.00,expense

examples/integrations/agentcore/agents/langgraph-single-agent/tools/query_data.py

@@ -0,0 +1,25 @@
+# patterns/langgraph-single-agent/tools/query_data.py
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+import csv
+from pathlib import Path
+
+from langchain.tools import tool
+
+# Read at module load time — avoids file I/O on every tool invocation.
+_csv_path = Path(__file__).parent / "db.csv"
+try:
+    with open(_csv_path) as _f:
+        _cached_data = list(csv.DictReader(_f))
+except (FileNotFoundError, OSError) as e:
+    raise RuntimeError(f"query_data: cannot load sample data from {_csv_path}") from e
+
+
+@tool
+def query_data(query: str) -> list[dict]:
+    """
+    Query the database. Accepts natural language.
+    Always call this tool before displaying a chart or graph.
+    """
+    return _cached_data

examples/integrations/agentcore/agents/langgraph-single-agent/tools/todos.py

@@ -0,0 +1,66 @@
+# patterns/langgraph-single-agent/tools/todos.py
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+import uuid
+from typing import Literal, TypedDict
+
+from langchain.agents import AgentState as BaseAgentState
+from langchain.tools import ToolRuntime, tool
+from langchain_core.messages import ToolMessage
+from langgraph.types import Command
+
+# ToolRuntime is confirmed available at langchain.tools (langchain >= 1.2).
+# If you see an ImportError, verify your langchain version is >= 0.3.
+
+
+class Todo(TypedDict):
+    id: str
+    title: str
+    description: str
+    emoji: str
+    status: Literal["pending", "completed"]
+
+
+class AgentState(BaseAgentState):
+    todos: list[Todo]
+
+
+def _assign_ids(todos: list[dict]) -> list[dict]:
+    """Assign a uuid4 to any todo that has a missing or empty 'id'."""
+    for todo in todos:
+        if not todo.get("id"):
+            todo["id"] = str(uuid.uuid4())
+    return todos
+
+
+@tool
+def manage_todos(todos: list[Todo], runtime: ToolRuntime) -> Command:
+    """
+    Manage the current todos. Replaces the entire todo list.
+    Assigns a unique UUID to any todo that is missing one.
+    """
+    _assign_ids(todos)  # type: ignore[arg-type]
+
+    return Command(
+        update={
+            "todos": todos,
+            "messages": [
+                ToolMessage(
+                    content="Successfully updated todos",
+                    tool_call_id=runtime.tool_call_id,
+                )
+            ],
+        }
+    )
+
+
+@tool
+def get_todos(runtime: ToolRuntime) -> list[Todo]:
+    """
+    Get the current todo list from agent state.
+    """
+    return runtime.state.get("todos", [])
+
+
+todo_tools = [manage_todos, get_todos]