← AI Calendar

About AI Calendar

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.

How it works

Each chat message is sent with a snapshot of the calendar: the current time, your timezone, and your events from 45 days before to 45 days after today. The assistant reads that snapshot to answer questions, and changes the schedule only by calling one of three tools. The browser validates every tool result against a schema before applying it, then shows a toast so you can see exactly what changed.

Who makes it

AI Calendar is built and maintained by Kaiyu Hsu as one of a set of open-source AI app templates. It is a personal project, not a company product.