Trevor Whittingham • 1/29/2026

Add Tool Calling To A Foundation Models Session

This article explains how to add tool calling to Foundation Models sessions in Swift, allowing models to invoke Swift code and use results in responses. It covers creating a small data source (ArticleIndex actor), defining a tool with arguments and output, and integrating with SwiftUI. The focus is on keeping tools small, validating arguments, and using view models to manage sessions. Examples use Xcode 26.5 SDK and demonstrate a reading-list app where the model searches saved articles. The article emphasizes clean architecture and concurrent safety.

0 comments

#Swift #Foundation Models #Swiftui