Claude Fable 5, the first in @AnthropicAI’s Mythos model class, is now generally available and rolling out in GitHub Copilot. It is designed for long-horizon, autonomous coding and knowledge-work tasks. Try it out in @code or the GitHub Copilot app. https://github.blog/changelog/2026-06-09-claude-fable-5-is-generally-available-for-github-copilot/…

Claude Fable 5 is generally available for GitHub Copilot

Source: https://github.blog/changelog/2026-06-09-claude-fable-5-is-generally-available-for-github-copilot/ Claude Fable 5 from Anthropic is now available in GitHub Copilot, the first model in Anthropic’s Mythos class, designed for long-horizon, autonomous coding and knowledge-work tasks. Unlike other Claude models in GitHub Copilot, Claude Fable 5 requires data retention to operate Anthropic’s safety classifiers. Continue reading for more details. In our internal benchmarks on autonomous coding workflows, Fable 5 completed equivalent work with fewer tool calls and lower token consumption than previous Opus-tier models.

This model is billed at provider list pricing under Usage Based Billing. SeeGitHub Copilot’s pricing for models and requestsfor details.

Availability in GitHub Copilot

Claude Fable 5 will be available to Copilot Pro+, Max, Business, and Enterprise users. You’ll be able to select the model in the model picker in:

• Visual Studio Code in all modes (i.e., chat, ask, edit, and agent)
• Visual Studio
• Copilot CLI
• GitHub Copilot cloud agent
• GitHub Copilot app
• github.com
• GitHub Mobile iOS and Android
• JetBrains
• Xcode
• Eclipse

Rollout will be gradual. Check back soon if you don’t see it yet.

Enabling access

Copilot Enterprise and Copilot Business plan administrators must enable the Claude Fable 5 policy in Copilot settings. The policy is off by default.

Important: Claude Fable 5 requires data retention.As part of Anthropic’s safety architecture for this model, Anthropic retains prompts and outputs for up to 30 days to operate safety classifiers that detect harmful or abusive use. After 30 days, it deletes the prompts and outputs. Retained data isnot usedto train Anthropic’s models.

This data retention appliesonly to Claude Fable 5. All other Claude models in GitHub Copilot, including Claude Opus 4.8, Sonnet 4.5, and Haiku 4.5, continue to operate under Zero Data Retention (ZDR).

For more on how Anthropic handles this data, seeAnthropic’s commercial terms and data retention policy. Enabling the Claude Fable 5 policy constitutes acknowledgement of this requirement. Leaving it off keeps Claude Fable 5 unavailable to your organization.

Learn more

To explore all models available in GitHub Copilot, see ourdocumentation on modelsand get started with Copilot.

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