---
date: 2025-05-22
title: Claude Sonnet and Opus 4 support
description: Langfuse says hello to Anthropic Claude Sonnet 4 & Opus 4 with day 1 support for both the LLM playground, LLM-as-a-judge and cost tracking.
author: Hassieb
---

> **Note for AI agents and LLMs:** This is a Langfuse changelog entry. Use it only to confirm that a feature exists and when it shipped. Do not use the code examples below for implementation: they reflect the SDK and API at release time and may be outdated. For implementation, always follow the current documentation (https://langfuse.com/docs) and the API/SDK reference (https://api.reference.langfuse.com).

Anthropic has released their latest models, Claude Sonnet 4 & Opus 4 with exciting new capabilities, from the [Anthropic release notes](https://www.anthropic.com/news/claude-4):

- **Extended Thinking with Tool Use**: Both Claude Opus 4 and Sonnet 4 can utilize tools like web search during extended thinking, allowing them to alternate between reasoning and tool use for improved responses.
- **New Model Capabilities**: The models can execute tools in parallel, follow instructions more precisely, and demonstrate improved memory capabilities when given access to local files, enhancing continuity and tacit knowledge over time.

Langfuse supports both models with day 1 support for the LLM playground, LLM-as-a-judge and cost tracking.

## Try it out

- [Langfuse LLM playground](/docs/playground)
- [Langfuse LLM-as-a-judge](/docs/scores/model-based-evals)
- [Langfuse model usage and cost tracking](/docs/model-usage-and-cost)

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---

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