Alternative to https://github.com/langchain-ai/langgraph/pull/3124
Currently if a tool interrupts, the entire tool node executes again
after resuming. So tools can get executed twice if parallel tool calls
are generated. Here we allow ToolNode to accept tool calls, so we can
use the `Send` API to distribute the tool calls to multiple instances of
the tool node.
```python
from langchain_anthropic import ChatAnthropic
from langchain_core.tools import tool
from langgraph.checkpoint.memory import MemorySaver
from langgraph.prebuilt import create_react_agent
from langgraph.types import Command, Send, interrupt
@tool
def human_assistance(query: str) -> str:
"""Request assistance from a human."""
human_response = interrupt({"query": query})
return human_response["data"]
@tool
def get_weather(location: str) -> str:
"""Use this tool to get the weather."""
return "It's sunny!"
tools = [get_weather, human_assistance]
llm = ChatAnthropic(model="claude-3-5-sonnet-20240620")
agent = create_react_agent(
llm,
tools,
checkpointer=MemorySaver(),
tool_call_parallelism="parallel_tool_nodes",
)
user_input = (
"Could you please (1) request assistance for building an AI agent "
"from a human, and (2) search for the weather in Boston, MA? "
"Generate two tool calls at once."
)
config = {"configurable": {"thread_id": "1"}}
for event in agent.stream(
{"messages": [{"role": "user", "content": user_input}]},
config,
stream_mode="values",
):
event["messages"][-1].pretty_print()
```
```
...
```
```python
human_response = "You should check out LangGraph to build your agent."
human_command = Command(resume={"data": human_response})
for event in agent.stream(human_command, config, stream_mode="values"):
event["messages"][-1].pretty_print()
```
---------
Co-authored-by: Vadym Barda <vadym@langchain.dev>
- The result of these doesnt change once a node is created, and it's
fairly expensive to run, so great thing to cache
- There's a variety of errors that can come from inspecting the source
code of a function (part of what this does) so adding a catch-all
try-except block as this should be best-effort, not crash your graph
- The result of these doesnt change once a node is created, and it's fairly expensive to run, so great thing to cache
- There's a variety of errors that can come from inspecting the source code of a function (part of what this does) so adding a catch-all try-except block as this should be best-effort, not crash your graph
* Concepts page for the functional API
* How-to guides that show functional API implementations
* API reference for entrypoint, task, entrypoint.final
* Add functional API version to the workflows
---------
Co-authored-by: Vadym Barda <vadym@langchain.dev>
Co-authored-by: ccurme <chester.curme@gmail.com>
