LangFuse

Creator
Creator
Seonglae ChoSeonglae Cho
Created
Created
2025 May 13 16:32
Editor
Edited
Edited
2025 Jul 16 17:43

Langfuse focuses on operational logging and monitoring of LLM applications

LangSmith is a service provided by
LangChain
that supports experimentation, evaluation, debugging, and systematic development workflows for designing and iterating on LLM-based applications.
While
LangFuse
focuses on operational logging and monitoring of LLM applications, LangSmith is a dedicated end-to-end tool for LangChain that supports the entire development cycle of LLM applications.
LangFuse Usages
 

LangSmith

  • [Project = Session] Sessions are also referred to as "Projects" in the UI
    • Trace - an execution composed of a set of runs (UI-only, no fixed scheme)
      • Run - a unit of LLM call or function
        • Message - a unit of conversation request & answer

LangFuse

  • (Session) optional trace grouping from user side
    • Trace - a unit of interaction
      • Observation - a unit of LLM call or function

MLFlow

  • Run - an execution
    • Trace
      • Span - an action
LangSmith Run = LangFuse Observation
LangSmith Trace = LangFuse Session
 
 

Rate Limit

Are there any limits to the Langfuse API? - Langfuse
While the Langfuse API is extremely open and flexible, there are some limits to ensure the stability and performance of the platform.
Are there any limits to the Langfuse API? - Langfuse
Open Source LLM Observability via OpenTelemetry - Langfuse
How to connect Langfuse with OpenTelemetry to observe LLM applications.
Open Source LLM Observability via OpenTelemetry - Langfuse
 
 

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