GitHub's 18 September changelog says Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini and Grok 4.5 leave every Copilot surface on 19 October 2026. CloudNinjas restates that list and tells teams that hardcoded model names in pipelines will fail unless they switch before the cutoff.
Artificial Intelligence··Evening
The cutoff hits Chat, inline edits, Ask, Agent and completions together
GitHub says the six models will be deprecated across all GitHub Copilot experiences, including Copilot Chat, inline edits, ask and agent modes, and code completions, on 19 October 2026. CloudNinjas repeats that the retirement covers those same surfaces and that calls with old identifiers will fall back or fail once the date arrives. The changelog is the dated vendor notice; the CloudNinjas note is written for teams that embedded those names in pipelines.[1], [2]
Suggested replacements are Gemini 3.8 Flash, GPT-5.6 Sol, Luna and Grok 4.6
GitHub's table maps Gemini 3.7 Flash to Gemini 3.8 Flash, GPT-5.5 and GPT-5.4 to GPT-5.6 Sol, the two minis to GPT-5.6 Luna, and Grok 4.5 to Grok 4.6. CloudNinjas reprints the same pairing for operators updating CI and custom integrations.[1], [2]
Default enablement turns replacements on unless an admin already opted out
GitHub says that under default model enablement the suggested alternatives are automatically enabled for Copilot Enterprise and Copilot Business unless an administrator turned off the global default or disabled the model. CloudNinjas tells those admins to turn replacements on in Copilot model policies if they had switched the global default off, and to inventory hardcoded model names before 19 October.[1], [2]
