TypeScript

TanStack Form is written 100% in TypeScript with the highest quality generics, constraints, and interfaces to make sure the library and your projects are as type-safe as possible!

Infer form and field types#

TanStack Form works out your form's data type from its defaultValues. From there, each field name points to a value in that data shape, so field callbacks and form methods know which values belong at each path.

Don't write the full FormApi or FieldApi generic parameter lists by hand in application code. Those signatures may change as TanStack Form's type inference evolves. At component boundaries, use the adapter's *FormType, FieldWithValue<T>, AnyFieldApi, or the adapter's Any*FormApi helper, depending on what the component needs. The Splitting forms guide shows how to use each helper.

Compiler requirements#

Enable strict: true in your tsconfig.json so TypeScript can check field paths, values, and callbacks as intended. TanStack Form's types require TypeScript 5.4 or later.

Type changes between releases#

Improvements and corrections to TanStack Form's types may ship in patch releases. These changes don't affect runtime behaviour, but they may reveal a type error in application code that previously compiled.

If you need to plan for those updates, pin your TanStack Form adapter to an exact patch version and review any new type errors when upgrading. Changes to the runtime API continue to follow semantic versioning.