AI Calendar is a calendar you talk to: type "lunch with Sam tomorrow at noon" or "move my 3pm to Thursday" and an AI assistant creates, moves, and deletes events for you. It is also a free, MIT-licensed Next.js template you can fork.
AI Calendar pairs a month and week calendar with a chat assistant. Ask it a question about your schedule and it answers from your events; ask it to change something and it calls a typed tool that updates the calendar in front of you. You can also click any day or time slot to add an event by hand, and click an event to edit or delete it.
There is no sign-up and no server-side database. Events are saved in your browser's localStorage, so the calendar is yours and stays on your device. The assistant runs on eve, Vercel's agent framework, through Vercel AI Gateway; on the hosted demo you bring your own AI Gateway key.
The whole app is open source at https://github.com/kyh/ai-calendar — Next.js 16, React 19, Tailwind CSS, Base UI and eve — and is meant to be forked as a starting point for AI-native apps that act on user data through tools.