GitHub has begun rolling out OpenAI’s GPT-5.6 family across GitHub Copilot, and this time it arrives in three flavors. Announced on July 9, 2026, the lineup — Sol, Terra, and Luna — is designed so you can match the model to the job, whether that’s reasoning over a sprawling codebase, handling everyday agentic coding, or getting fast, low-cost help.
Table of Contents
Three Models, Three Jobs
Rather than a single one-size-fits-all model, GPT-5.6 splits into a tiered family. GPT-5.6 Sol sits at the top with the highest reasoning ceiling, making it the pick for complex reasoning across large codebases and demanding, long-running agentic work. GPT-5.6 Terra is the balanced default — a strong all-rounder for everyday interactive and agentic coding. GPT-5.6 Luna is the lightweight, cost-efficient option for smaller, faster tasks, and it’s also the cheapest model in the family.
| Variant | Positioning | Best for |
|---|---|---|
| Sol | Highest reasoning ceiling | Complex reasoning over large codebases; long-running agentic work |
| Terra | Balanced default | Everyday interactive and agentic coding |
| Luna | Lightweight, lowest cost | Smaller, faster tasks |
Who Gets What
Availability depends on your Copilot plan. Sol is limited to Copilot Pro+, Max, Business, and Enterprise, while Terra and Luna reach a wider audience across Pro, Pro+, Max, Business, and Enterprise. All three are billed at provider list pricing under Usage-Based Billing, so costs scale with what you actually use.
Where to Use Them
Once rolled out to your account, the models appear in the model picker across a broad set of surfaces: Visual Studio Code, Visual Studio, the Copilot CLI, the GitHub Copilot cloud agent, the GitHub Copilot app, github.com, GitHub Mobile on iOS and Android, JetBrains, Xcode, and Eclipse. The rollout is gradual, so if you don’t see the models yet, they should appear soon.
Admin Action Required for Business and Enterprise
There’s one important catch for organizations. Copilot Business and Enterprise administrators must explicitly enable the GPT-5.6 policy in Copilot settings — it’s off by default. Until an admin flips that switch, users on those plans won’t see the new models regardless of the rollout schedule.
Bottom Line
The GPT-5.6 family gives Copilot users a clearer trade-off between reasoning power and cost: reach for Sol when a task demands deep reasoning, stay on Terra for daily work, and drop to Luna when speed and price matter more than raw capability. Just remember that Business and Enterprise teams need an admin to enable the models first.
