Category
stayInformed
Severity
normal
Major change
False
Last modified
2025-12-16 22:27:26
Summary source
Azure OpenAI (gpt-4.1)
Action by (Graph)
—
Action by (AI)
2026-01-01 00:00:00
Services
Microsoft Copilot (Microsoft 365)
Tags
Updated message, New feature, User impact, Admin impact
Master tags
—
Roadmap IDs
One-line summary
Microsoft 365 Copilot declarative agents will upgrade to GPT-5.1 with auto model selection, starting rollout in early January 2026 and enabled by default for all tenants.
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Details
Summary
Microsoft 365 Copilot declarative agents will upgrade to the GPT-5.1 model with an auto architecture, rolling out worldwide from early January to mid-January 2026. The advanced reasoning model will handle complex queries, enabled by default with no admin changes or required user action.
Body (from Message Center)
Updated December 16, 2025: We have updated the timeline. Thank you for your patience.
[Introduction]
Microsoft 365 Copilot declarative agents are upgrading to the GPT-5.1 model, which uses an “auto” architecture. The orchestrator will automatically select the best model for each scenario, either the fast “chat” model or the advanced reasoning model, based on the user prompt.
[When this will happen]General Availability (Worldwide): Rollout will begin early January 2026 (previously mid-December 2025) and is expected to complete by mid-January 2026.
[How this affects your organization]Who is affected: All tenants using Microsoft 365 Copilot declarative agents.
What will happen:
- Declarative agents will upgrade to GPT-5.1.
- The advanced reasoning model will be available for complex queries.
- No admin configuration changes are required.
- Feature will be enabled by default for all applicable tenants.
No action is required.
[Compliance considerations]No compliance considerations identified. Review as appropriate for your organization.
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"Summary": "Microsoft 365 Copilot declarative agents will upgrade to the GPT-5.1 model with an auto architecture, rolling out worldwide from early January to mid-January 2026. The advanced reasoning model will handle complex queries, enabled by default with no admin changes or required user action."
},
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"title": "(Updated) Microsoft 365 Copilot: Declarative agents model upgrade to GPT-5.1"
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