Uploaded October 2025 | Updated September 2026, 1 day ago
As the landscape of AI applications has rapidly evolved with multimodal models and sophisticated tool calls, a new foundation is required for building modern applications. In this talk, Lars Grammel ( https://x.com/lgrammel ) from the Vercel AI SDK team will introduce AI SDK 5, a major rewrite designed to meet these challenges. Lars will explain why this breaking change was necessary, moving away from an incremental approach that struggled with diverging provider APIs. He will detail the architecture of AI SDK 5, focusing on its three core pillars: a revamped provider specification, a fully type-safe UI and chat layer, and new controls for creating sophisticated agentic tool-calling loops.
What you'll discover:
➡️ The "Why" behind AI SDK 5: Understand the challenges of incremental development that led to a major rewrite.
➡️ New Provider architecture: Learn about the v2 provider spec that supports ordered, multimodal outputs and provider-executed tools.
➡️ End-to-end type safety: See how typed metadata, data parts, and tool calls enable building complex, maintainable UI components.
➡️ Building agentic loops: Discover new controls like the `prepare` step and `stopWhen` conditions for managing multi-step tool-calling agents.
➡️ Enhanced chat capabilities: Explore the more powerful and flexible chat components with swappable transports and UI framework independence.
➡️ The future of AI SDK: Get a sneak peek at upcoming features, including improved telemetry and image editing capabilities.
See you at other Callstack events ✨ clstk.com/42u9oCh
Check out more AI content from Callstack 📚 clstk.com/3I2xWv1
Follow Callstack on X 🐦 https://x.com/callstackio
As the landscape of AI applications has rapidly evolved with multimodal models and sophisticated tool calls, a new foundation is required for building modern applications. In this talk, Lars Grammel ( https://x.com/lgrammel ) from the Vercel AI SDK team will introduce AI SDK 5, a major rewrite designed to meet these challenges. Lars will explain why this breaking change was necessary, moving away from an incremental approach that struggled with diverging provider APIs. He will detail the architecture of AI SDK 5, focusing on its three core pillars: a revamped provider specification, a fully type-safe UI and chat layer, and new controls for creating sophisticated agentic tool-calling loops.
What you'll discover:
➡️ The "Why" behind AI SDK 5: Understand the challenges of incremental development that led to a major rewrite.
➡️ New Provider architecture: Learn about the v2 provider spec that supports ordered, multimodal outputs and provider-executed tools.
➡️ End-to-end type safety: See how typed metadata, data parts, and tool calls enable building complex, maintainable UI components.
➡️ Building agentic loops: Discover new controls like the `prepare` step and `stopWhen` conditions for managing multi-step tool-calling agents.
➡️ Enhanced chat capabilities: Explore the more powerful and flexible chat components with swappable transports and UI framework independence.
➡️ The future of AI SDK: Get a sneak peek at upcoming features, including improved telemetry and image editing capabilities.
See you at other Callstack events ✨ clstk.com/42u9oCh
Check out more AI content from Callstack 📚 clstk.com/3I2xWv1
Follow Callstack on X 🐦 https://x.com/callstackio
