---
format: "aidr-story-markdown/v1"
id: "b6c650abd54e6aeee49af5b10cd321c955299c7f9f6e49c19c8c1a60fac06c90"
canonical_url: "https://aidr.today/b6c650ab?lang=en"
title: "Anthropic New Marshmallow Model Beats Opus 5, First Major Update Since Fable 5"
lang: "en"
requested_lang: "en"
available_langs: ["en","vi"]
translation_fallback: null
fallback_fields: []
published_at: "2026-08-23T20:44:01.000Z"
category: "Models"
topics: ["anthropic","claude","llm","benchmark"]
source_urls: ["https://huggingnews.com/ai/anthropic-new-marshmallow-model-beats-opus-5-first-major-update-since-fa-5221e5eb","https://x.com/Lentils80/status/2091586112552669649","https://x.com/MaxForAI/status/2091578019819475033","https://x.com/kimmonismus/status/2091599817084412221","https://x.com/MichaelKaiserAI/status/2091622861681107195"]
summary: "Anthropic has introduced two new internal language models to its early access program to test potential updates to its Claude AI family. Testing of claude-marshmallow-eap and claude-melon-eap indicates that Marshmallow outperforms Melon and provides a superior conversational experience to Opus 5, though neither model matches the capabilities of Fable. The EAP suffix identifies internal checkpoints used for evaluation before a public deployment. This naming convention was previously used for the Fruitcake and Honeycomb models prior to the launch of Fable 5, suggesting a forthcoming release for the Opus or Haiku lines."
---

# Anthropic New Marshmallow Model Beats Opus 5, First Major Update Since Fable 5

> [Open the canonical story](<https://aidr.today/b6c650ab?lang=en>)

**Published:** 2026-08-23T20:44:01.000Z
**Category:** Models
**Topics:** anthropic, claude, llm, benchmark

## Summary

Anthropic has introduced two new internal language models to its early access program to test potential updates to its Claude AI family\. Testing of claude\-marshmallow\-eap and claude\-melon\-eap indicates that Marshmallow outperforms Melon and provides a superior conversational experience to Opus 5, though neither model matches the capabilities of Fable\. The EAP suffix identifies internal checkpoints used for evaluation before a public deployment\. This naming convention was previously used for the Fruitcake and Honeycomb models prior to the launch of Fable 5, suggesting a forthcoming release for the Opus or Haiku lines\.

## Sources

- [Story source](<https://huggingnews.com/ai/anthropic-new-marshmallow-model-beats-opus-5-first-major-update-since-fa-5221e5eb>)
- [Story source](<https://x.com/Lentils80/status/2091586112552669649>)
- [Supporting source](<https://x.com/MaxForAI/status/2091578019819475033>)
- [Supporting source](<https://x.com/kimmonismus/status/2091599817084412221>)
- [Supporting source](<https://x.com/MichaelKaiserAI/status/2091622861681107195>)