Quick answer: if GPT-5.6 appears in your GitHub Copilot model picker, use GPT-5.6 Terra as the everyday default, GPT-5.6 Sol for complex reasoning across large codebases or long-running agentic work, and GPT-5.6 Luna for smaller, faster, cost-conscious tasks.
GitHub announced on July 9, 2026 that OpenAI’s GPT-5.6 family is rolling out in GitHub Copilot. The rollout is gradual, so some users may not see the models immediately. For Copilot Business and Enterprise, administrators must enable the GPT-5.6 model policy in Copilot settings before users can access it.
GPT-5.6 Copilot model picker cheat sheet
| Model | Best use | Use it when | Availability noted by GitHub |
|---|---|---|---|
| GPT-5.6 Sol | Highest reasoning ceiling | You need deep analysis, large-codebase reasoning, difficult debugging, or demanding long-running agentic work. | Copilot Pro+, Max, Business and Enterprise |
| GPT-5.6 Terra | Balanced default | You want a strong all-round model for everyday interactive coding and agentic coding. | Copilot Pro, Pro+, Max, Business and Enterprise |
| GPT-5.6 Luna | Lightweight / cost-efficient | You need fast help for smaller tasks, simple refactors, explanations, quick tests or lower-cost assistance. | Copilot Pro, Pro+, Max, Business and Enterprise |
What changed?
- GitHub says GPT-5.6 is rolling out in three variants: Sol, Terra and Luna.
- GitHub positions Sol for complex reasoning over large codebases and long-running agentic work.
- GitHub positions Terra as the balanced default for everyday coding.
- GitHub positions Luna as the lightweight, lowest-cost option in the GPT-5.6 family.
- The models can be selected in VS Code, Visual Studio, Copilot CLI, GitHub Copilot cloud agent, GitHub Copilot app, github.com, GitHub Mobile, JetBrains, Xcode and Eclipse, according to GitHub’s changelog.
Admin checklist for Copilot Business and Enterprise
- Open your organization or enterprise Copilot settings.
- Find the model policy / AI model access controls.
- Enable access to the GPT-5.6 models if you want users to test them. GitHub says this policy is off by default for Business and Enterprise.
- Start with a small pilot group before enabling for every developer.
- Track cost and usage because GitHub says these models are billed under usage-based billing at provider list pricing.
- Tell developers when to use Sol, Terra and Luna so expensive reasoning is reserved for work that needs it.
Suggested model selection rules
Use GPT-5.6 Sol for
- Architecture reviews across many files.
- Hard bugs where the first fix may not be obvious.
- Long-running Copilot agent sessions.
- Security-sensitive code review where deeper reasoning is useful.
- Migration plans that touch several services or repositories.
Use GPT-5.6 Terra for
- Normal Copilot Chat coding help.
- Daily refactors and feature implementation.
- Unit test generation.
- Explaining code and APIs.
- Most agentic coding tasks where you do not need the highest reasoning level.
Use GPT-5.6 Luna for
- Small snippets and quick syntax help.
- Simple documentation edits.
- Short explanations.
- Low-risk code cleanup.
- Cost-conscious workflows where speed matters more than maximum reasoning.
Prompt templates to test each GPT-5.6 model
Sol test prompt:
Review this repository's authentication flow. Identify the main files involved, map the request lifecycle, find risky edge cases, and propose a staged fix plan with tests.
Terra test prompt:
Help me implement this feature with minimal changes. Explain the files to edit, write the code, and add unit tests for the expected behavior.
Luna test prompt:
Summarize what this function does, list any obvious bugs, and suggest a simpler version if needed.
Important pricing note
GitHub says GPT-5.6 models are billed at provider list pricing under usage-based billing and points users to the Copilot model pricing documentation. In the pricing documentation retrieved during this post, the GPT-5.6 rows were not visible yet, so this article does not quote exact per-token prices. Check GitHub’s live pricing page before rolling the models out broadly.
FAQ
Why do I not see GPT-5.6 in Copilot yet?
GitHub says the rollout is gradual. If you are on Business or Enterprise, an admin may also need to enable the GPT-5.6 model policy first.
Which GPT-5.6 model should I choose first?
Start with Terra for normal coding. Move to Sol when the task needs deeper reasoning or a long agentic workflow. Use Luna when the task is small, fast and cost-sensitive.
Is GPT-5.6 available on Copilot Pro?
GitHub says Terra and Luna are available to Copilot Pro, Pro+, Max, Business and Enterprise. GitHub lists Sol for Pro+, Max, Business and Enterprise.
Can agencies and development teams use this for client work?
Yes, but treat model selection as an operations policy. For teams building client software or AI workflows, a simple rule like “Terra by default, Sol by approval, Luna for quick tasks” can help balance quality and spend. Media87 can help businesses design these AI coding and automation workflows when a broader implementation plan is needed.