Genuinely one of the more approachable builds on this whole register — Google Calendar and Microsoft Graph both expose free/busy lookups in a single API call, and the rest is bounded slot math and one transactional email.
Build it
Effort: an eveningRunning cost: $0/mo to start
Why CanICodeThis says Build it
Google Calendar and Microsoft Graph both expose free/busy lookups in a single request — the core logic is under a hundred lines
Slot math (timezones, buffers, working hours) is fiddly but bounded — a few test cases covering DST and cross-timezone bookings get it right
Email confirmation is one transactional-mail call, and the invite itself is a standard .ics attachment
The parts that'll cause problems
Round-robin routing across a whole sales team is where a real scheduling product earns its per-seat price
Polished embeds and the trust of a domain people already recognize don't come with a fresh build
Someone else being on the hook when a double-booking bug costs a real meeting is worth something too
How I'd build this
frontend
Astro
calendar
Google Calendar API
email
Resend
hosting
Cloudflare Pages
MVP scope
A public booking page showing available slots pulled from calendar free/busy
Timezone-aware slot selection with buffers
Email confirmation with a calendar invite attached
Postpone to v2
Round-robin routing across a team
Custom branding and embeds
Payment collection for paid consultations
What it actually costs to build
AI agent — with a subscription (Claude Pro/Max, Cursor, etc.)
$0 marginal
AI agent — pay-per-use API, no subscription
$16–$27 one-time
Hosting, once it's running
$0/mo (free tier)
Domain name, if you want your own
~$12/yr
Existing tools solving a similar problem typically run $6.95–$12/mo — see how they compare below.
The build prompt
Genuinely one of the more approachable builds on this whole register:
1. Pull free/busy data from Google Calendar's API — a single request gives you the core availability logic.
2. Show available slots with timezone conversion and configurable buffers — fiddly but bounded, a handful of test cases covering DST and cross-timezone bookings get it right.
3. Send an email confirmation with a .ics calendar invite attached when someone books.
Single person, no team routing. That's a real, working booking page. Out of scope: round-robin routing across a whole sales team, genuinely where a real scheduling product earns its per-seat price, and payment collection for paid consultations, a real, separate Stripe integration.
