LangChain Reference home page

GitHub
Main Docs

LangGraph

Web
Channels
Pregel
Prebuilt
Remote

React SDK

Vue SDK

Svelte SDK

Angular SDK

LangGraph SDK

Ui
Client
Auth
React
Logging
React Ui
Utils
Server

LangGraph Checkpoint

LangGraph Checkpoint MongoDB

LangGraph Checkpoint Postgres

Store

LangGraph Checkpoint Redis

Shallow
Store

LangGraph Checkpoint SQLite

LangGraph Checkpoint Validation

Cli

LangGraph API

LangGraph CLI

LangGraph CUA

Utils

LangGraph Supervisor

LangGraph Swarm

⌘I

LangChain Assistant

Ask a question to get started

Enter to send•Shift+Enter new line

Menu

Web Channels Pregel Prebuilt Remote

Ui Client Auth React Logging React Ui Utils Server

LangGraph Checkpoint

LangGraph Checkpoint MongoDB

LangGraph Checkpoint Postgres

LangGraph Checkpoint Redis

LangGraph Checkpoint SQLite

LangGraph Checkpoint Validation

LangGraph Supervisor

LangGraph Swarm

Language

Theme

JavaScript@langchain/langgraph-sdkuiUseStreamOptionsonTool

Property●Since v1.8

onTool

Callback for headless tool lifecycle events.

Copy

onTool: OnToolCallback

View source on GitHub