Formity - Open source package

Overview

Forms are everywhere on the web, but building truly dynamic multi-step forms in React has always been a challenge. While existing libraries make simple forms manageable, they quickly fall apart when the flow needs to adapt based on user input. That's where Formity comes in—a library designed to make creating interactive, conditional, multi-step forms not only possible but seamless.

The Problem

React developers have long relied on popular libraries like React Hook Form, Formik, and TanStack Form to handle form state and validation. These tools work well for basic forms, but they're not built for flows that change in real-time—where one answer can affect the next step, skip an entire section, or even loop through a set of questions.

Building that kind of experience usually requires a lot of custom logic, scattered state management, and fragile conditionals that become harder to maintain as the form grows. There was no clear solution for handling complex form logic in a clean, reusable way—let alone one that also made the forms look great.

What I Built

To address the limitations of existing tools, I built Formity, a form engine designed from the ground up for dynamic, logic-driven flows. Rather than treating a form as a static list of steps, Formity models it as a living process—one that can branch, loop, and respond to user input in real time. Developers can define conditions, variables, and loops directly within the form structure, allowing for complex behaviors to emerge naturally, without resorting to scattered logic across components.

To complete the experience, I created Formity UI, which brings together a fully styled UI kit and an AI-powered form builder. The UI kit includes ready-made components inspired by Typeform's conversational design, while the AI form builder turns natural language prompts into fully structured multi-step forms that work seamlessly with the kit. Together, they make it effortless to go from idea to implementation in minutes.

Results

Formity has significantly reduced the effort required to build complex forms in React. What used to take days of planning, coding, and testing can now be done in a fraction of the time. Developers get full control over the form logic while enjoying a smooth, type-safe development experience thanks to robust TypeScript support. The addition of Formity UI also means teams can ship clean, interactive forms with minimal effort.

Takeaway

Formity fills a critical gap in the React ecosystem by offering a dynamic, logic-driven approach to building multi-step forms. It enables developers to go beyond static flows and create truly interactive user experiences—without the typical overhead. With its blend of form logic, UI components, and AI-assisted creation, Formity brings power and simplicity together in a way that didn't exist before.