Building Type-safe AI Applications - Nico Albanese, Vercel

Description

You can now build type-safe AI applications using agents with the Vercel AI SDK. Nico Albanese from Vercel’s AI SDK team walks through practical patterns for turning AI agents into production-ready apps. Using a real example - automating social media threads from GitHub pull requests - he shows how to set up web apps with AI SDK UI components, create API routes, and build chat interfaces. Nico tackles a core challenge in AI development: keeping tool schemas in sync. The SDK solves this by making the agent the single source of truth for types. Nico also discusses streaming tool execution updates and preliminary results to improve the user experience. Nico Albanese works on the AI SDK at Vercel, focusing on developer experience and tools for TypeScript AI developers. The Vercel AI SDK is a free, open-source TypeScript toolkit for building AI-powered products. Created by the team behind Next.js, it offers unified APIs for multiple AI providers and framework-agnostic support (React, Next, Vue, Nuxt, Svelte). 🔗 CONNECT WITH NICO ALBANESE LinkedIn: https://www.linkedin.com/in/nicoalbanese Twitter/X: https://x.com/nicoalbanese10 GitHub: https://github.com/nicoalbanese Website: https://www.nicoalbanese.com Vercel AI SDK: https://sdk.vercel.ai 📚 MASTRA RESOURCES Mastra: https://mastra.ai Learn Mastra in the world's first MCP-Based Course: https://mastra.ai/course Principles of Building AI Agents (Book): https://mastra.ai/book Patterns for Building AI Agents (New Book): https://mastra.ai/blog/patterns-book https://docs.google.com/forms/d/e/1FAIpQLSduJjc515f6RZJqtkR2ByqJZrB0iP8B7SUKnjjZE9IajH_I8w/viewform The TypeScript AI conference is the first conference for TypeScript AI developers. The inaugural event took place on November 6, 2025, in San Francisco and online. MASTRA? Mastra is an open-source TypeScript framework designed for building and shipping AI-powered applications and agents with minimal friction. It supports the full lifecycle of agent development—from prototype to production. You can integrate it with frontend and backend stacks (e.g., React, Next.js, Node) or run agents as standalone services. If you’re a JavaScript or TypeScript developer looking to build an agentic or AI-powered product without starting from first principles, Mastra provides the scaffolding, tools, and integrations to accelerate that process. 00:00 Intro 00:54 Your Agent is Ready: Application Deployment 02:00 Demo: Social Launch Agent 02:58 AI SDK UI Components 03:35 Creating the API Route Handler 03:53 Building the Frontend with useChat Hook 05:40 Tool Calls and Customizing Tool Rendering 07:23 Tool Name Changes and Schema Maintenance 08:13 Type-Safe Tool Schemas 09:00 Creating Custom UI Message Types 10:32 Integrating Type-Safe Messages into the Frontend 11:21 Streaming Updates 12:20 Preliminary Tool Results 13:03 Real-Time Tool Status Streaming 14:03 Refactoring Tool UI into Maintainable Components 15:15 Further AI SDK Capabilities