Summary
- Copilot Studio will only support the GPT-6 Astra and GPT-5.6 Terra models when OpenAI is enabled as a sub-processor in the tenant.
- If OpenAI sub-processor use is disabled, agents configured with those models will automatically fall back to alternate models.
- Admins should review Copilot Studio agent inventory to identify affected agents, noting that unpublished model changes may not appear in inventory.
- Microsoft recommends testing fallback or replacement models and updating agent instructions/configuration as needed before the change takes effect.
Primary Service: Power Platform
Admin Impact: Medium
User Impact: Medium
Release Start: 15 Oct 2026
Release End: 15 Oct 2026
Services: Power Platform
Category: Plan for change
Tags: Highlighted
History
10/14/2026 Item Added to Message Center
Microsoft Message
Due to capacity constraints, starting on October 15, 2026, Copilot Studio will support the OpenAI models GPT-6 Astra and GPT-5.6 Terra only when OpenAI is enabled as a sub-processor.
What’s changing?
Microsoft Copilot Studio offers OpenAI models through two delivery mechanisms: Microsoft operated models through Azure OpenAI, or OpenAI operated models as a sub-processor in Microsoft Online Services. The Microsoft 365 admin center includes a control for managing whether you allow OpenAI to operate models as a sub-processor in your tenant.
On October 15, 2026, support for GPT-6 Astra and GPT-5.6 Terra in Copilot Studio will only be available when OpenAI is enabled as a sub-processor in your tenant. If OpenAI is disabled as a sub-processor, agents using the GPT-6 Astra and GPT-5.6 Terra models will use the following fallback models:
| Current model | Fallback model |
|---|---|
| GPT-6 Astra | GPT-6 Sol |
| GPT-5.6 Terra | GPT-6 Luna |
How does this affect me?
If OpenAI is enabled as a sub-processor for all users in your tenant, then none of your agents are affected and there is no action for you to take. If OpenAI is disabled as a sub-processor for some or all users in your tenant, then any agents using the GPT-6 Astra and GPT-5.6 Terra models will instead use the fallback models listed in the above table.
What action do I need to take?
We advise that you enable OpenAI as a sub-processor for all users, so there will be no changes to the models currently used by your agents. If you do not want to enable OpenAI as a sub-processor for some or all users, please take the following action:
- Access the Power Platform admin center, then navigate to Manage > Copilot Studio. Review your agents to identify those using the GPT-6 Astra or GPT-5.6 Terra models.
Please note that the model field is currently in preview: The inventory reflects published agent configurations, so unpublished model changes might not appear. Please see the admin agent inventory.
Once the affected agents have been identified, please perform the following actions:
- Notify the owners of the agents of this change.
- Test the planned fallback models, or another supported model, to ensure response accuracy, key workflows, tool and action execution, and business-critical integrations are not affected.
- Make changes as needed and adjust any agent instructions or configuration based on your test results.
For more information, please review the following documentation:
- OpenAI as a subprocessor in Microsoft Online Services
- Test your agent
- Copilot Studio model lifecycle guidance
- Copilot Studio agent inventory