I Built an Ontology Firewall for Microsoft Copilot in 48 Hours — Here’s the Production Code

Last Updated on March 4, 2026 by Editorial Team Author(s): Pankaj Kumar Originally published on Towards AI. Most Copilot deployments are one bad agent action away from a serious production failure. This is the architecture that prevents it. 📌 GitHub Repository: cloudbadal007/copilot-ontology-firewall The Copilot had read a SharePoint document titled “Pre-Approved Vendor List — Draft” and interpreted “Pre-Approved” as authorization to proceed. The word “Draft” was in the filename. The agent never checked it.This article details the construction of an Ontology Firewall specifically designed for Microsoft Copilot, highlighting the risks inherent to deployments that lack proper safeguards. Through a recounting of a real incident involving an unauthorized multimillion-dollar contract approval, the article outlines the importance of a robust semantic layer in AI operations. It also provides a build guide, broken down into sequential stages, for creating and deploying the Ontology Firewall, emphasizing its necessity for maintaining compliance and operational integrity in enterprise settings. Read the full blog for free on Medium. Join thousands of data leaders on the AI newsletter. Join over 80,000 subscribers and keep up to date with the latest developments in AI. From research to projects and ideas. If you are building an AI startup, an AI-related product, or a service, we invite you to consider becoming a sponsor. Published via Towards AI