Harvey AI Integrates Custom Agents Directly into Microsoft Word

Harvey AI has launched a major update to its Microsoft Word Add-In, enabling legal teams to run their custom AI agents directly within Word documents. This new functionality, announced on September 23, 2026, allows users to deploy tailored agents for tasks like contract reviews, redlining, and summarization without switching platforms.

These custom agents are built using Harvey’s Agent Builder tool, which lets teams encode their preferred legal standards, positions, and workflows. With the latest integration, these agents now operate seamlessly on open Word documents, using the document’s content as context and pulling in additional files from Harvey’s Vault if needed. For instance, a master services agreement (MSA) review agent can identify deviations in terms like liability caps or data protection clauses, returning standardized feedback in a team-specific format.

Streamlining Legal Workflows

This update builds on Harvey’s broader strategy of embedding AI into the Microsoft 365 ecosystem. Harvey’s Word Add-In already includes features like Playbooks for repeatable workflows, document redaction, and real-time drafting and editing. By introducing custom agents into Word, Harvey eliminates the need for lawyers to toggle between applications, a step that could save significant time and reduce errors in legal reviews.

Notably, suggestions made by the agents are presented as tracked changes in Word, preserving transparency and allowing users to accept, modify, or reject edits. Multiple review sessions are supported through Harvey’s threaded chat feature, ensuring continuity for complex or ongoing projects.

Legal AI Meets Microsoft 365

This release is part of Harvey’s ongoing collaboration with Microsoft, which was expanded in July 2026. The partnership aims to integrate Harvey’s legal AI capabilities across Microsoft 365 apps, including Outlook, SharePoint, and Copilot. The Word Add-In plays a central role in this initiative, providing a unified platform for drafting, editing, and managing legal documents.

Harvey’s legal AI tools are increasingly being adopted by law firms and corporate legal departments to enforce compliance and streamline routine processes. According to vendor-reported data, Playbooks embedded in the Word Add-In have reduced NDA review times by over 60%. While this figure hasn’t been independently verified, it highlights the potential efficiency gains for users adopting the platform.

Availability and Next Steps

The Custom Agents feature is now live for organizations using the Harvey for Word Add-In. Teams can install the add-in via Microsoft AppSource or through their IT departments. For detailed setup instructions, users can refer to the Harvey Help Center.

While custom workflows built outside the Agent Builder UI aren’t yet supported, the company has signaled that further updates will expand functionality. With its integration into Word, Harvey AI continues to position itself as a key player in the growing LegalTech market, which increasingly relies on AI to optimize workflows.

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