📅 Scheduling · $12/mo

Can I vibe code Calendly?

Share your availability; let people book time with you.

🟡Kinda — with gapsest. a weekend

The booking page itself is easy: show open slots, take a booking, write a calendar event. What's genuinely hard is the correctness — real-time two-way sync with Google/Outlook, timezone edge cases, double-booking prevention, and reschedule/cancel flows. You can build a personal version in a weekend, but matching Calendly's reliability across calendars is where the real work hides.

The one-shot prompt
Build a personal Calendly alternative: a public booking page where visitors schedule time with me. Requirements: connect to my Google Calendar via OAuth and read free/busy so I'm never double-booked; let me configure event types (duration, buffer, daily limits, and the weekly hours I'm bookable) in a config file; show available slots converted to the visitor's detected timezone; on booking, create the calendar event with a Google Meet link and email both parties a confirmation with reschedule/cancel links. Handle DST carefully, prevent race-condition double-bookings with a database lock, and use Next.js App Router deployable to Vercel. Call out any timezone edge cases I should test.
Paste into Claude Code, Codex, or your agent of choice — then steer. Learn the moves in Prompt Engineering.
What you build

A public booking page that reads your free/busy from Google Calendar, offers open slots in the visitor's timezone, and writes the event on confirmation.

What you give up
  • Battle-tested two-way sync across Google, Outlook, and iCloud
  • Team scheduling, round-robin, and routing forms
  • Reminders, buffers, and payment collection without building each one
  • Timezone and DST edge cases they've handled for a decade
Why people still pay

Scheduling looks trivial and is not — the moat is a thousand handled edge cases and reliable calendar sync. Getting that wrong means a missed meeting, so people happily pay to never think about it.

reliabilityintegrations
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Actually build it

A prompt is the first move, not the whole game. Course 01 teaches you to take a prompt like this one to a shipped, working app — reviewing, correcting, and steering the agent the whole way.

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