Kin FormForm state that stays out of your way

Fast. Lightweight. Framework-agnostic. 100% type-safe.

🌳

One model, one class

FieldApi for leaf inputs, nested objects and arrays alike; FormApi is just the FieldApi at the root, plus submit handling. A form is just a tree of nodes, mirroring the DOM's own Node/Document shape.

🔑

Type-safe dot paths

form.field("address.line1") or form.field("items.0.code") type-checks against your value type. DeepKey/DeepValue compute every valid path and its value type — typos are compile errors, not runtime surprises.

🧩

Build once, reuse anywhere

Build a field, group, or button component once — TextField, AddressField, SubmitButton — and mount it anywhere.

🔗

Cross-field validation, declaratively

Declare dependents on a field to re-validate siblings whenever it changes — "confirm password must match password" without wiring up manual subscriptions.

📚

Dynamic arrays

pushItem/insertItem/moveItem/swapItems/removeItem update the immutable value and re-key the field registry together, so a field's identity follows its item through a reorder.

🧪

Two validation models, your choice

Per-node validators for granular rules, or a whole-group schemaValidator adapting any Standard Schema library (zod, valibot, ...).

How it compares

	Kin Form	React Hook Form	Formik	TanStack Form
Zero dependencies	✅	✅	❌	⚠️
Type-safe nested field paths	✅	✅	❌	✅
Built-in async-validation debounce	✅	❌	❌	✅

✅ full support · ⚠️ partial or conditional · ❌ not supported

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