Opus 4.8 Now Available in Harvey

What's New

We’ve added Opus 4.8 to the model selector in Harvey. Opus 4.8 builds on Opus 4.7 with gains in legal accuracy, output quality, and self-review behavior.

Learn more about our evaluation of this model in our blog post for Opus 4.8.

Why It Matters

Opus 4.8 delivers improvements across three areas:

• Legal accuracy: More reliable identification of case captions, parties, statutory provisions, and applicable doctrinal frameworks.
• Output calibration: Responses are better sized for the task, not over- or under-explained.
• Self-review behavior: Opus 4.8 often reviews and revises its own outputs before returning an answer, which leads to stronger performance on drafting tasks.

For most workflows, Auto mode continues to select the right model for you, but model selection is available if you want more direct control.

This update ensures Harvey adapts to different types of legal work without changing how you normally use it.

How to Use

Open Model Selector in Assistant, Vault, or Workflow Builder to select Opus 4.8 from the list of models. Admins can manage access through Access Control & Permission Management.

Important: Both models require the Model Selector; Opus 4.8 is only available with Claude permissions enabled. If you don’t see the Model Selector, contact your workspace admin or Customer Success Manager.