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LangGraph

Web
Channels
Pregel
Prebuilt
Remote
Stream

Overview
Getting started
useStream
Selectors
Interrupts & headless tools
Subagents & subgraphs
Fork & edit from a checkpoint
Submission queue
Multimodal media
Transports
provideStream & context
Type safety
Migrating to v1

LangGraph SDK

Client
Auth
React
Logging
React Ui
Server

LangGraph Checkpoint

LangGraph Checkpoint MongoDB

LangGraph Checkpoint Postgres

LangGraph Checkpoint Redis

Shallow
Store

LangGraph Checkpoint SQLite

LangGraph Checkpoint Validation

Cli

LangGraph API

LangGraph CLI

LangGraph CUA

Utils

LangGraph Supervisor

LangGraph Swarm

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Web Channels Pregel Prebuilt Remote Stream

Overview Getting started useStream Selectors Interrupts & headless tools Subagents & subgraphs Fork & edit from a checkpoint Submission queue Multimodal media Transports provideStream & context Type safety Migrating to v1

Client Auth React Logging React Ui 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/svelteUseAgentStreamOptionsonTool

Property●Since v1.2

onTool

Callback for headless tool lifecycle events.

Copy

onTool: OnToolCallback

View source on GitHub