LangChain Reference home pageLangChain ReferenceLangChain Reference
  • GitHub
  • Main Docs
Deep Agents
LangChain
LangGraph
Integrations
LangSmith
LangChain
  • Browser
  • Universal
  • Hub
  • Node
  • Load
  • Serializable
  • Encoder Backed
  • File System
  • In Memory
  • Tools
LangChain Core
  • Agents
  • Caches
  • Base
  • Dispatch
  • Web
  • Manager
  • Promises
  • Chat History
  • Context
  • Base
  • Langsmith
  • Documents
  • Embeddings
  • Errors
  • Example Selectors
  • Indexing
  • Base
  • Chat Models
  • Llms
  • Profile
  • Structured Output
  • Load
  • Serializable
  • Memory
  • Messages
  • Tool
  • Output Parsers
  • Openai Functions
  • Openai Tools
  • Outputs
  • Prompt Values
  • Prompts
  • Retrievers
  • Document Compressors
  • Runnables
  • Graph
  • Singletons
  • Stores
  • Structured Query
  • Testing
  • Tools
  • Base
  • Console
  • Log Stream
  • Run Collector
  • Tracer Langchain
  • Stream
  • Async Caller
  • Chunk Array
  • Context
  • Env
  • Event Source Parse
  • Format
  • Function Calling
  • Hash
  • Json Patch
  • Json Schema
  • Math
  • Ssrf
  • Standard Schema
  • Stream
  • Testing
  • Tiktoken
  • Types
  • Vectorstores
Text Splitters
MCP Adapters
⌘I

LangChain Assistant

Ask a question to get started

Enter to send•Shift+Enter new line

Menu

LangChain
BrowserUniversalHubNodeLoadSerializableEncoder BackedFile SystemIn MemoryTools
LangChain Core
AgentsCachesBaseDispatchWebManagerPromisesChat HistoryContextBaseLangsmithDocumentsEmbeddingsErrorsExample SelectorsIndexingBaseChat ModelsLlmsProfileStructured OutputLoadSerializableMemoryMessagesToolOutput ParsersOpenai FunctionsOpenai ToolsOutputsPrompt ValuesPromptsRetrieversDocument CompressorsRunnablesGraphSingletonsStoresStructured QueryTestingToolsBaseConsoleLog StreamRun CollectorTracer LangchainStreamAsync CallerChunk ArrayContextEnvEvent Source ParseFormatFunction CallingHashJson PatchJson SchemaMathSsrfStandard SchemaStreamTestingTiktokenTypesVectorstores
Text Splitters
MCP Adapters
Language
Theme
JavaScript@langchain/corecontext
Moduleā—Since v0.3

context

Copy
import { ... } from "@langchain/core/context";

Used in Docs

  • Build a SQL assistant with on-demand skills

Functions

function
getContextVariable→ T | undefined
function
registerConfigureHook
function
setContextVariable

Type Aliases

Variables

View source on GitHub
typeAlias
ConfigureHook
variable
foo: "bar"

Get the value of a previously set context variable. Context variables are scoped to any child runnables called by the current runnable, or globally if set outside of any runnable.

Register a callback configure hook to automatically add callback handlers to all runs.

There are two ways to use this:

  1. Using a context variable:

    • Set contextVar to specify the variable name
    • Use setContextVariable() to store your handler instance
  2. Using an environment variable:

    • Set both envVar and handlerClass
    • The handler will be instantiated when the env var is set to "true".

Set a context variable. Context variables are scoped to any child runnables called by the current runnable, or globally if set outside of any runnable.