LangSmithExporter

Sends AI tracing data to LangSmith for observability.

Constructor

new LangSmithExporter(config: LangSmithExporterConfig)

LangSmithExporterConfig

interface LangSmithExporterConfig extends ClientConfig {
  logLevel?: "debug" | "info" | "warn" | "error";
  client?: Client;
}

Methods

exportEvent

async exportEvent(event: AITracingEvent): 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

AI Span Type	LangSmith Type
LLM_GENERATION	llm
LLM_CHUNK	llm
TOOL_CALL	tool
MCP_TOOL_CALL	tool
All others	chain