tanstack-form

Build type-safe forms with synchronous and asynchronous validation using a headless form state manager that provides fine-grained reactivity. It supports debounced async checks, deep TypeScript field path safety, and schema adapters like Zod without locking you into a specific UI library.

Handle cross-field revalidation for dependent inputs by attaching listeners that trigger validation on related fields when one changes. This ensures fields like password and confirm password stay consistent as the user types, maintaining correct meta state via onChange and onBlur handlers.

Yes, you can validate form fields asynchronously using Zod schema adapters. The system supports validators that return undefined for valid inputs, integrates zod-form-adapter for schema-based rules, and allows debounced asynchronous checks like username availability directly within the form state.

Add and remove dynamic array fields by configuring array fields with mode="array". This approach manages dynamic lists of items, such as a list of contacts, while preserving deep TypeScript field path safety and maintaining correct validation state across the added or removed items.

Headless form state management works with server-side validation by integrating with server actions in frameworks like Next.js. It wires onBlur and onChange handlers to maintain correct meta state on the client, seamlessly bridging frontend reactivity with backend validation responses.