---
type: email
from: Marc Klingen <marc@updates.langfuse.com>
subject: Langfuse September Update: AI Filters, Experiment Runner SDK & Price Drop
received: 2026-03-06 07:55:17
date_header: Thu, 2 Oct 2025 13:58:07 +0000
priority: normal
status: awaiting_approval
uid: 31776
---

## Email Content

**From:** Marc Klingen <marc@updates.langfuse.com>
**Subject:** Langfuse September Update: AI Filters, Experiment Runner SDK & Price Drop
**Date:** Thu, 2 Oct 2025 13:58:07 +0000

### Body (preview)

Hi Ubaidurrehman Usman,

September was a big month. We shipped a new Experiment Runner SDK, introduced our first AI feature, rolled out structured outputs

for prompt experiments, graduated our TypeScript SDK v4 to GA, and a 50% price drop for the Core plan.

Quick highlights below. Links go straight to docs so you can dive in fast.

 





Experiment Runner SDK



https://langfuse.com/docs/evaluation/experiments/experiments-via-sdk#experiment-runner-sdk



We've added a new high-level SDK abstraction that makes running experiments on datasets a breeze. It comes with automatic tracing,

concurrent execution, and flexible evaluation built in.

This is now the recommended way to run experiments on local or Langfuse-hosted datasets with our Python and JS/TS SDKs.

→ Learn more in the docs [https://langfuse.com/docs/evaluation/experiments/experiments-via-sdk#experiment-runner-sdk]

 





Natural Language Filtering for Traces



https://langfuse.com/changelog/2025-09-30-natural-language-filters



You can now filter your traces and observations using plain English. Just describe what you're looking for, and Langfuse will

construct the right filters for you.

You can then refine them manually if needed. This is our first AI feature in Langfuse, with more to follow!

→ See how it works [https://langfuse.com/changelog/2025-09-30-natural-language-filters]

 





Structured Output Support for Prompt Experiments



https://langfuse.com/changelog/2025-09-30-structured-output-experiments



Ensure your LLM responses conform to a specific JSON schema in your Prompt Experiments. Enforcing a structured output makes it

much easier to evaluate outputs consistently and process results programmatically.

→ Read the changelog [https://langfuse.com/changelog/2025-09-30-structured-output-experiments]

 





TypeScript SDK v4 (GA)



https://www.youtube.com/watch?v=BjEXs13KyV4



We’ve taken JS/TypeScript tracing up a notch: The Langfuse JS/TypeScript SDK v4

[https://langfuse.com/d

---

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