$ show OfficeDev/Office-Add-in-samples
This is a large collection of over 1000 sample projects and templates for developing Microsoft Office Add-ins (Excel, Word, Outlook, PowerPoint, OneNote). The repository demonstrates a wide range of features: task panes, custom functions, authentication/SSO (MSAL, nested app auth, OAuth), Microsoft Graph integration, Blazor WebAssembly add-ins, shared runtime, event-based activation for Outlook, ribbon customization, keyboard shortcuts, offline storage, and legacy VSTO/COM samples. The codebase spans multiple technology stacks including JavaScript/TypeScript with webpack, ASP.NET Core MVC, Node.js, and Blazor. While many samples are functional and serve as good learning resources, the repository suffers from massive duplication of localization files (outlook_strings.js in dozens of languages) and outdated dependencies (jQuery 1.9.1, AngularJS, VSTO). The overall code quality is typical of sample collections – functional but not production-grade – with isolated reusable patterns for authentication and Graph API interaction.
The LLM identified 4 files worth highlighting for reuse:
A reusable TypeScript module that makes authenticated calls to Microsoft Graph API with support for Continuous Access Evaluation (CAE). It handles token acquisition via an AccountManager, constructs requests with proper headers, and on 401 errors retries after processing a claims challenge. This pattern can be extracted and used in any Office Add-in or web app needing resilient Graph API access.
A Node.js module that validates JWT tokens from Azure AD by fetching the OpenID configuration and JWKS keys. It performs issuer and audience checks, replaces the common issuer with the tenant-specific issuer, and attaches auth info to the request. This is a self-contained middleware pattern for any backend needing to validate Azure AD tokens.
Implements a fallback authentication dialog using MSAL when Nested App Authentication (NAA) is not available. It creates a nestable public client application, acquires tokens silently with popup fallback, and uses Office dialog API to communicate the result. This pattern is essential for handling cross-platform auth in Office Add-ins and can be reused directly.
A Blazor WebAssembly component that demonstrates bidirectional JavaScript interop with Office.js. Uses JSHost.ImportAsync to import a SharedUtils module, JSInvokable methods to call back from Office, and IJSRuntime to invoke Office APIs for creating slides. This pattern is reusable for any Blazor-based Office Add-in needing to interact with the host application.