Microsoft makes GPT‑5.6 default

Microsoft has told employees working in GitHub Copilot to default to OpenAI’s GPT-5.6 Sol, according to an internal memo reviewed by CNBC. The instruction came from Jay Parikh, executive vice president of Microsoft’s CoreAI group, whose organization includes GitHub, Visual Studio and Visual Studio Code. CNBC reported on August 5 that the guidance applied to staff use of Copilot, not to customer defaults. The move came weeks after GitHub said GPT-5.6 Sol, Terra and Luna were rolling out in Copilot. ### Who inside Microsoft made the change? Jay Parikh issued the direction to staff this week, CNBC reported, telling developers to use GPT-5.6 Sol most of the time when working in GitHub Copilot. CNBC said Parikh framed the decision as part of an efficiency push tied to Microsoft’s rights stemming from its OpenAI investment. (cnbc.com) Microsoft has not announced a comparable customer-wide change for GitHub Copilot. A GitHub changelog published July 9 said customers could access multiple GPT-5.6 variants inside Copilot, with Sol positioned for more demanding coding and reasoning tasks, Terra as the balanced option and Luna as the faster, lower-cost model. (cnbc.com) ### Why would Microsoft steer staff toward one model? CNBC reported that Microsoft is trying to get employees to use AI tools more efficiently after a period in which developers were encouraged to spend freely on tokens. The memo, as described by CNBC, tied the preference for GPT-5.6 Sol to “token investment value,” meaning Microsoft saw a financial advantage in routing more internal usage to OpenAI’s flagship model. (github.blog) That cost logic sits inside a broader commercial relationship. Bloomberg reported, and other outlets summarized, that Microsoft disclosed $24.1 billion in revenue from OpenAI for the fiscal year ended June 2026. BigGo Finance said that figure represented roughly 70% of Microsoft’s AI sales, underscoring how much of Microsoft’s AI business still runs through OpenAI despite efforts to broaden its model lineup. (cnbc.com) ### Does this mean GitHub Copilot now runs only on OpenAI? GitHub’s own product materials say no. The July 9 changelog described GPT-5.6 as one family among selectable models in Copilot, with different variants aimed at different workloads rather than a single mandatory engine. (bloomberg.com) CNBC’s report also drew a line between internal policy and product behavior. The article said Microsoft staff were being nudged toward a preferred default, while still having access to other options as models and products evolve. ### Why does the OpenAI tie matter so much to Microsoft? (github.blog) Microsoft’s latest disclosures gave investors a clearer view of the relationship’s scale. Bloomberg reported that most of Microsoft’s AI revenue comes from OpenAI, while BigGo said the filing showed OpenAI contributed $24.1 billion during the fiscal year ended in June through cloud usage, model-development costs and revenue-sharing arrangements. (cnbc.com) GitHub Copilot is also a large enough product for internal defaults to matter. Microsoft said last week that Copilot had reached 50 million users, according to reports citing the company, which means even internal usage policies can signal how Microsoft wants to balance cost, performance and partner economics across a major coding platform. (bloomberg.com) ### What happens next? GitHub’s July 9 changelog said the GPT-5.6 family was rolling out across Copilot, and CNBC reported that Parikh told staff defaults would be updated as models and products change. That leaves Microsoft’s internal policy tied to future model releases and to any further changes in the company’s OpenAI partnership disclosures. (github.blog) (blockgeni.com)