Footnotes GPT-5.4 nano is currently only available in the Codex Visual Studio Code extension (Copilot Pro+ only) and is not available in Copilot Chat. ↩ ↩ 2 ↩ 3 When Claude Fable 5 is used, Anthropic retains data, including prompts and outputs, to operate safety classifiers that detect harmful use.
https://docs.github.com/en/copilot/reference/ai-models/supported-models