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langfuse-langchain

v3.39.2

Published

LEGACY Langfuse v3 integration for LangChain (maintenance mode). For new projects use the current CallbackHandler from @langfuse/langchain: npm install @langfuse/langchain @langfuse/otel

Vulnerabilities

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Links

Git

Maintainers

bezbacbezbacmdeichmannmdeichmannmarliessophiemarliessophiehassiebhassiebmarcklingenmarcklingenwochingewochinge

Keywords

langfuselegacydeprecatedlangchainllmobservability

Readme

GitHub Banner

Langfuse JS/TS

MIT License npm package GitHub Repo stars Discord YC W23

[!IMPORTANT] This package is not the latest Langfuse JS/TS SDK. langfuse-langchain is the deprecated v3 LangChain integration. Do not use it for new instrumentation.

Latest setup: npm install @langfuse/langchain @langfuse/otel @opentelemetry/sdk-node and use CallbackHandler from @langfuse/langchain. Docs: https://langfuse.com/integrations/frameworks/langchain — Upgrade: v3 → v4, v4 → v5.

Query traces with Observations API v2 (GET /api/public/v2/observations, API reference), not GET /api/public/traces / api.traceList.

Data freshness: the only real-time path is OpenTelemetry ingestion (@langfuse/otel, or any OTel exporter sending x-langfuse-ingestion-version: 4) combined with the Observations API v2 and Metrics API v2. All other GET APIs from all SDK packages can be up to 10 minutes behind.

This is the JS/TS client for the Langfuse Langchain integration.

Documentation

  • Docs: https://langfuse.com/docs/integrations/langchain
  • Reference: https://js.reference.langfuse.com/modules/langfuse_langchain.html

Environments

Supported

  • Node.js >=20
  • Web
  • Edge: Vercel, Cloudflare Workers, etc.

Installation

npm i langfuse-langchain
# or
yarn add langfuse-langchain
# or
pnpm i langfuse-langchain