Announcing Claude Opus 4.5 in Microsoft Copilot Studio

Based on the Microsoft Copilot blog post from November 24, 2025, here is the information regarding the announcement of Claude Opus 4.5 in Copilot Studio:

Announcing Claude Opus 4.5 in Microsoft Copilot Studio

This update marks the integration of Anthropic’s most powerful model into the Copilot Studio platform, providing developers with advanced reasoning and long-context capabilities for building complex agents.

Real-time User Journey

The user journey for Claude Opus 4.5 centers on high-complexity, multi-step problem solving:

1. Complexity Identification: A developer identifies a business process that requires deep reasoning over vast amounts of data (e.g., analyzing a 200-page legal contract alongside historical case files).
2. Model Selection: Within Copilot Studio, the developer selects Claude Opus 4.5 as the reasoning engine for their agent.
3. Interaction: The end-user provides a high-level goal, such as “Identify all conflicting clauses in these five documents and suggest a reconciliation strategy based on our internal compliance handbook.”
4. Long-Context Reasoning: The agent utilizes the model’s massive context window to ingest all documents simultaneously, maintaining the “thread” across long, multi-step logic paths.
5. Execution: The agent produces a highly nuanced output, citing specific sections of the context provided, and can trigger follow-up actions like drafting an email to the legal team.

Step-by-Step: How to Enable

As an experimental model, Claude Opus 4.5 requires administrative permission to use:

• Step 1: Admin Opt-in: A Microsoft 365 Administrator must log in to the Microsoft 365 Admin Center.
• Step 2: External Model Settings: Navigate to the settings for external AI models and explicitly opt-in to Anthropic models (if not already done).
• Step 3: Access Copilot Studio: Once opted in, go to Microsoft Copilot Studio.
• Step 4: Create/Open an Agent: Open an existing agent or create a new one.
• Step 5: Select Model: Go to Settings > Generative AI. Under the model selection dropdown, choose Claude Opus 4.5 (Experimental).
• Step 6: Test: Use the “Test your agent” pane to validate how the new model performs with your specific prompts and knowledge base.

Infographic: Claude Opus 4.5 Core Strengths

The following table highlights why Claude Opus 4.5 is positioned as the “premium” choice for complex agents:

Feature	Capability	Benefit for Agents
Sharper Reasoning	Advanced logical deduction.	Solves “impossible” problems that stump smaller models.
Long-Context	Handles massive datasets.	Reads hundreds of pages in a single turn without losing focus.
Multi-Step Tasks	Stronger instruction following.	Executes complex sequences of actions with high accuracy.
Model Choice	Multi-vendor flexibility.	Allows developers to use Agent Evaluations to pick the best model for the job.

References

Announcing Claude Opus 4.5 in Microsoft Copilot Studio