AI-Powered Office Add-ins

AI-powered Office add-ins call the OpenAI or ChatGPT APIs from inside Microsoft 365 apps, so generative AI runs where your team already works. We build them for Excel, Word, Outlook, and PowerPoint. Concrete use cases include GPT-powered formula suggestions in Excel, an AI writing assistant in the Word task pane, automated slide content and speaker notes in PowerPoint, and an email drafting assistant in Outlook. Every AI add-in we build ships production-ready, and we handle AppSource publishing so it reaches users through the Microsoft marketplace. This service is for businesses that want AI capabilities inside the tools their teams use every day rather than another standalone app, and the demand is real: OpenAI's API processes over 10 million requests per day across enterprise integrations. Connecting these models securely — Azure OpenAI endpoints, function calling, and API key management — is its own discipline, handled by our AI integration for Office add-ins service. We build these alongside our app-specific work, including Excel add-ins, Word add-ins, PowerPoint add-ins, and Outlook add-ins. AI add-ins that call OpenAI are different from Microsoft Copilot extensions, which extend Microsoft 365 Copilot itself; see our Microsoft Copilot extensions service.

An underwriting team at a specialty insurer had quietly started pasting claim summaries into a public chatbot to draft coverage position letters. The drafts were decent; the compliance exposure was not. Rather than ban the habit, the insurer asked us to give it a sanctioned home. We built a Word task pane assistant backed by Azure OpenAI in their own subscription, with the app registration and permissions handled through our Microsoft Entra setup work, so prompts never leave their tenant and every generation is logged with the file and author. Underwriters kept the drafting speed they had discovered on their own, legal got an audit trail, and the public-chatbot habit died out within weeks because the in-document version was simply closer to hand.

A custom AI build is worth it when the model needs your context: house style, policy wording, live data from your systems. If people just need general drafting help, a Copilot license per user is simpler than custom work, and if you want Microsoft 365 Copilot itself answering from your data, that is Copilot extension territory rather than an Office.js project. We scope which of the three actually fits before writing code.