Claude Code 2.1.306, Copilot Model Retirements and Codex 0.164 Alphas: October 21 Roundup

It is a quieter day than yesterday's roundup, but two things matter: Claude Code moved from 2.1.304 to 2.1.306, and GitHub's Copilot model retirements took effect on October 19. Codex only shipped alpha builds and OpenCode has no release newer than 1.19.3, so those two get short notes below.

Claude Code 2.1.305 and 2.1.306: sandbox and reliability fixes

According to the Claude Code changelog, version 2.1.305 adds a sandbox.allowNestedUserNamespaces setting for sandboxed Linux commands that need user namespaces. The notes warn it can bypass the sandbox's file protections, so enable it only where a tool genuinely requires it. It also adds a variable for unattended retry mode to notice when usage limits lift, makes requests retry without tool search when a provider rejects it, and fixes a batch of issues in worktrees, /usage, screen reader mode and Remote Control.

Version 2.1.306 is a fix release: claude -p in cloud sessions no longer reports "Not logged in" when started without the session's environment variables, an API error is no longer replaced by a misleading "prompt is too long" message, and sessions with many MCP tools avoid an unneeded compaction. Version 2.1.303 only lists bug fixes and reliability improvements.

GitHub Copilot: older models retired

GitHub's October 19 deprecation notice lists the retired models and suggested replacements: Gemini 3.7 Flash to Gemini 3.8 Flash, GPT-5.5 and GPT-5.4 to GPT-6.1 Sol, GPT-5.4 mini and GPT-5 mini to GPT-6 Luna, and Grok 4.5 to Grok 4.7. The change covers most Copilot experiences, including chat, inline edits, ask and agent modes, and completions. GitHub first announced it on September 18.

Enterprise admins may need to enable the replacement models in their model policies before they appear in the model picker; the new model policy API can help automate that. More retirements are scheduled, see the mid-November deprecation notice.

Codex and OpenCode: no new stable releases

The Codex releases page still marks 0.163.0 (October 15) as the latest stable build; 0.164.0 alphas were being cut through October 20 without release notes. On OpenCode's releases page, the newest version is still 1.19.3 from October 16. Both are covered in yesterday's roundup.

What to do this week

• Claude Code users: update to 2.1.306, and leave nested user namespaces off unless a sandboxed command needs them.
• Copilot users and admins: check that nothing pins a retired model and that replacements are enabled in policy.
• Codex users: stay on 0.163.0 rather than alpha builds for production work.

References

Claude Code CHANGELOG · Codex releases · OpenCode releases · GitHub Copilot changelog