LangChain Reference home pageLangChain ReferenceLangChain Reference
  • GitHub
  • Main Docs
Deep Agents
LangChain
LangGraph
Integrations
LangSmith
LangGraph
  • Web
  • Channels
  • Pregel
  • Prebuilt
  • Remote
  • Stream
LangGraph SDK
  • Ui
  • Client
  • Auth
  • React
  • Logging
  • React Ui
  • Utils
  • Server
  • Stream
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

LangGraph
WebChannelsPregelPrebuiltRemoteStream
LangGraph SDK
UiClientAuthReactLoggingReact UiUtilsServerStream
LangGraph Checkpoint
LangGraph Checkpoint MongoDB
LangGraph Checkpoint Postgres
Store
LangGraph Checkpoint Redis
ShallowStore
LangGraph Checkpoint SQLite
LangGraph Checkpoint Validation
Cli
LangGraph API
LangGraph CLI
LangGraph CUA
Utils
LangGraph Supervisor
LangGraph Swarm
Language
Theme
JavaScript@langchain/langgraphindexEventLog
Classā—Since v0.3

EventLog

Copy
class EventLog

Constructors

Properties

Methods

View source on GitHub
constructor
constructor
property
channelName: string
property
done: boolean
property
size: number
method
[asyncIterator]→ AsyncIterator<T>
method
close
method
fail
method
get→ Value
method
iterate→ AsyncIterator<T>
method
push
method
toAsyncIterable→ AsyncIterable<T>
method
toEventStream→ ReadableStream<Uint8Array<ArrayBufferLike>>
method
isInstance→ value is DeltaValue<Value, Input>
method
local→ EventLog<T>
method
remote→ EventLog<T>

A projection channel for StreamTransformers.

Implements AsyncIterable<T> so it can be iterated directly by in-process consumers via run.extensions.<key>. Channels created with StreamChannel.remote or new StreamChannel(name) are also auto-forwarded to remote clients.

Protocol channel name used for auto-forwarded events, if remote.

Mark the channel as complete after all buffered items are consumed.

Mark the channel as failed after all buffered items are consumed.

Return the current value of the channel.

Returns an async iterator starting at position startAt. Each call returns an independent cursor so multiple consumers can iterate the same channel concurrently.

Append an item to the channel. If this is a remote channel wired to a mux, the item is also injected into the main protocol event stream under channelName.

Creates an AsyncIterable backed by this channel, starting from startAt.

Creates a web ReadableStream that emits channel items as Server-Sent Events. Useful for returning a channel directly from new Response(channel.toEventStream()).

Type guard to check if a value is a DeltaValue instance.

Create an in-process-only channel. Values remain available through run.extensions.<key> but are not forwarded to remote clients.

Create a channel whose pushes are forwarded to remote clients under the given protocol channel name.