LangChain Reference home pageLangChain ReferenceLangChain Reference
  • GitHub
  • Main Docs
Deep Agents
LangChain
LangGraph
Integrations
LangSmith
LangChain
  • Universal
  • Hub
  • Node
  • Load
  • Serializable
  • Encoder Backed
  • File System
  • In Memory
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
  • Load
  • Serializable
  • Memory
  • Messages
  • Tool
  • Output Parsers
  • Openai Functions
  • Openai Tools
  • Outputs
  • Prompt Values
  • Prompts
  • Retrievers
  • Document Compressors
  • Runnables
  • Graph
  • Singletons
  • Stores
  • Structured Query
  • 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
  • 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
UniversalHubNodeLoadSerializableEncoder BackedFile SystemIn Memory
LangChain Core
AgentsCachesBaseDispatchWebManagerPromisesChat HistoryContextBaseLangsmithDocumentsEmbeddingsErrorsExample SelectorsIndexingBaseChat ModelsLlmsProfileLoadSerializableMemoryMessagesToolOutput ParsersOpenai FunctionsOpenai ToolsOutputsPrompt ValuesPromptsRetrieversDocument CompressorsRunnablesGraphSingletonsStoresStructured QueryToolsBaseConsoleLog StreamRun CollectorTracer LangchainStreamAsync CallerChunk ArrayContextEnvEvent Source ParseFormatFunction CallingHashJson PatchJson SchemaMathSsrfStreamTestingTiktokenTypesVectorstores
Text Splitters
MCP Adapters
Language
Theme
JavaScript@langchain/coretracersrun_collector
Moduleā—Since v1.0

tracers/run_collector

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

Classes

class
RunCollectorCallbackHandler

A callback handler that collects traced runs and makes it easy to fetch the traced run object from calls through any langchain object. For instance, it makes it easy to fetch the run ID and then do things with that, such as log feedback.

View source on GitHub