---
title: "Redeploying Claude Fable 5"
description: "Access to Claude Fable 5 and Mythos 5 was restored after US export controls had temporarily suspended both models for all users. The post says Fable 5 will return globally on July 1 across Claude Platform, Claude.ai, Claude Code, and Claude Cowork, while Mythos 5 access has resumed for some US organizations and broader partner access remains under discussion. Anthropic describes a new safety classifier intended to block the bypass reported by Amazon researchers in more than 99% of cases; blocked Fable 5 requests are sent to Opus 4.8, although the classifier increases false positives in coding and debugging. It also outlines defense-in-depth safeguards, a proposed shared industry framework for assessing jailbreaks, and expanded government collaboration on pre-release evaluation, information sharing, and joint research."
---

# Redeploying Claude Fable 5

[Anthropic](https://yomu.fyi/company/anthropic) · Jul 1, 2026

**Type:** Announcement

## Summary

Access to Claude Fable 5 and Mythos 5 was restored after US export controls had temporarily suspended both models for all users. The post says Fable 5 will return globally on July 1 across Claude Platform, Claude.ai, Claude Code, and Claude Cowork, while Mythos 5 access has resumed for some US organizations and broader partner access remains under discussion. Anthropic describes a new safety classifier intended to block the bypass reported by Amazon researchers in more than 99% of cases; blocked Fable 5 requests are sent to Opus 4.8, although the classifier increases false positives in coding and debugging. It also outlines defense-in-depth safeguards, a proposed shared industry framework for assessing jailbreaks, and expanded government collaboration on pre-release evaluation, information sharing, and joint research.

## Context

US export controls applied to Fable 5 and Mythos 5 on June 12, requiring access restrictions for foreign nationals. Because there was no reliable way to verify nationality in real time, access to both models was suspended for all users. The controls were lifted on June 30.

## Approach / What changed

Anthropic redeployed Fable 5 globally and restored Mythos 5 access for selected US organizations. It also trained a safety classifier to block the reported safeguard bypass, routes blocked Fable 5 requests to Opus 4.8, and proposes broader industry and government collaboration on evaluations, safeguards, and jailbreak assessment.

## Takeaways

- The export-control directive led to a full suspension because the systems could not reliably verify users’ nationality in real time.
- The improved classifier blocks the specific technique described in the Amazon report in more than 99% of cases, but it also flags benign coding and debugging requests more often.
- Fable 5 uses defense in depth, combining refusal training, misuse analysis, and cybersecurity classifiers with a deliberately broad safety margin.

**Tags:** [AI Security](https://yomu.fyi/topic/ai-security), [Claude](https://yomu.fyi/topic/claude)

- Source: [Anthropic](https://www.anthropic.com/news/redeploying-fable-5)
- Source URL: https://www.anthropic.com/news/redeploying-fable-5
- Ingested by Yomu: 2026-09-09T11:38:10.415Z

[Read original post](https://www.anthropic.com/news/redeploying-fable-5)