LangSmithExporter

Sends Tracing data to LangSmith for observability.

Constructor

new LangSmithExporter(config: LangSmithExporterConfig)

LangSmithExporterConfig

interface LangSmithExporterConfig extends ClientConfig, BaseExporterConfig {
  client?: Client;
}

Extends both ClientConfig (from LangSmith SDK) and BaseExporterConfig:

From BaseExporterConfig: logger?: IMastraLogger, logLevel?: LogLevel | 'debug' | 'info' | 'warn' | 'error'
From ClientConfig: apiKey, apiUrl, callerOptions, hideInputs, hideOutputs, etc.

Methods

exportTracingEvent

async exportTracingEvent(event: TracingEvent): Promise<void>

Exports a tracing event to LangSmith.

shutdown

async shutdown(): Promise<void>

Ends all active spans and clears the trace map.

Usage

import { LangSmithExporter } from "@mastra/langsmith";

const exporter = new LangSmithExporter({
  apiKey: process.env.LANGSMITH_API_KEY,
  apiUrl: "https://api.smith.langchain.com",
  logLevel: "info",
});

Span Type Mapping

Span Type	LangSmith Type
`MODEL_GENERATION`	`llm`
`MODEL_CHUNK`	`llm`
`TOOL_CALL`	`tool`
`MCP_TOOL_CALL`	`tool`
All others	`chain`

Constructor​

LangSmithExporterConfig​

Methods​

exportTracingEvent​

shutdown​

Usage​

Span Type Mapping​