Langfuse Core

[!IMPORTANT] This SDK is deprecated. The Langfuse TypeScript SDK was completely rewritten and released as v4 in August 2025. Please refer to the TypeScript SDK documentation for migration instructions.

This is the core package for the Langfuse JS/TS client libraries. It is not meant to be used directly.

Reference: https://js.reference.langfuse.com/modules/langfuse_core.html

Client Libraries

Package	NPM	Environments
langfuse		Node >= 18, Web, Edge
langfuse-node		Node < 18
langfuse-langchain		Node >= 20, Web, Edge