GitHub Copilot retires Claude Opus 4.8, Opus 5 and GPT-5.6 Terra on Nov 16

GitHub announced on October 15 that three models will leave GitHub Copilot on November 16, 2026: Claude Opus 4.8, Claude Opus 5, and GPT-5.6 Terra. The cutoff covers every Copilot experience: Chat, inline edits, ask and agent modes, and code completions.

#What happened

Per GitHub's changelog, the deprecation takes effect November 16, 2026. Claude Opus 4.8 stays available only for individual Copilot subscribers on annual plans; team and enterprise seats lose all three. GitHub's suggested alternatives: Claude Opus 5.5 replaces both Opus models, and GPT-6.1 Sol or GPT-6 Luna replaces GPT-5.6 Terra. For Business and Enterprise customers, the alternatives are enabled automatically unless an admin turned off the global default. GitHub's own note: "Please update your workflows and integrations to use the supported models before this date."

#Why it matters

This is the largest single-day model cut GitHub has made to Copilot, and it lands while rivals are expanding: OpenAI's Codex CLI moved 0.161 to 0.163 in October with GPT-6.1 Sol as the default, Cursor 0.45 shipped cross-repo mapping, and Meta and Reflection AI released open-weight coding models. Any workflow or CI job that pins one of the three retiring model names by ID should be migrated now.

Verified Oct 20, 2026.