OpenAI's GPT-6.1 Terra Model Surfaces in Microsoft Code, Signaling Near-Term Launch

OpenAI's new GPT-6.1 Terra model has emerged from a Microsoft pull request, with evaluation configuration files updated to test the unreleased model across 18 test scenarios. On October 16, 2026, Microsoft merged changes to its Entity Framework Core repository that upgraded internal evaluation configs from GPT-5.6 Terra to GPT-6.1 Terra, replacing the predecessor model as the default judge in testing routines. The discovery, first identified by AI researchers, reveals OpenAI preparing infrastructure for a model that has not yet received an official announcement or public availability.