Review · Benchmark 1: SlotKeeper
Replit built a working booking app; the free deploy lasts 29 days


Live app at slot-keeper-booking-app--ownersenderrepl.replit.app, captured Oct 25, 2026, opening with “Find your own rhythm.” Slot dates and spots left are today's, not the test day's. Replit's free deploy stops about 29 days after Oct 24, 2026.
From the test day
Select any screenshot to open it full size.
Design: polish 4, mobile 4, clarity 3.5 (raw 11.5 of 15), one reviewer.
§01 Verdict
On its free plan, Replit Agent finished building in about 13 minutes and the app was live about 23 minutes after we sent the prompt, with no fix prompts. It passed all 10 checks with 5 minor bugs. Owner sign-in used Replit's built-in Clerk sign-in instead of an in-app form. Score: 83.625/100.
§02 How it went
- We submitted the prompt at 04:03 ET. The agent reported "Worked for 13 minutes" and finished at about 04:16, with about 10 progress messages and 1 checkpoint.
- It fixed its own TypeScript build error. The preview pane kept showing a React version-mismatch overlay, but the published site was fine.
- We clicked Publish at 04:21; the app was live at about 04:26.
- No human interventions, no clarifying questions, no fix prompts.
- Deploy
- In-tool Publish to a working public URL; Replit set up Postgres and sign-in with no extra steps.
- Cost
- $0. The free published app expires in 29 days.
- Stack
- PostgreSQL; owner sign-in through Replit-managed Clerk (email and password, Google, email code). The first signed-in account claims the owner role.
- Model
- Not recorded
- App URL
- slot-keeper-booking-app--ownersenderrepl.replit.app (Replit Agent's app, opens in a new tab) (recorded on Oct 24, 2026; test data only. Free deploy expires about 29 days after Oct 24, 2026.)
§03 Checklist
- Landing page lists the 3 seeded slots with spots left.PASS
- Booking with a valid name and email succeeds, a confirmation shows, and spots go down by 1.PASS
- A missing name or invalid email is rejected with a clear message.Browser pop-ups only.PASS
- Data persists after a hard refresh (redeploy not tested).After a hard refresh. Redeploy not re-tested.PASS (refresh)
- A full slot (capacity 1, after one booking) shows "Join waitlist" and assigns a waitlist position.PASS
- The same email can't double-book the same slot.Rejected, with a raw HTTP 409 message.PASS
- The owner can sign up and log in, and logged-out /admin redirects to login.Owner sign-in through Clerk at /sign-in; logged-out /admin redirects.PASS
- The owner can create, edit and delete a slot.Delete asks for confirmation.PASS
- Cancelling a booking promotes the first waitlisted person automatically.PASS
- Stats line counts are correct, and it all works on the public deployed URL.PASS
§04 What broke
- MINOR
Form errors show only as the browser's own pop-ups.
To reproduce: Submit the booking form with an empty name or the email "abc".
- MINOR
A repeat booking shows the raw message "HTTP 409 : This email already has a reservation for this slot."
To reproduce: Book the same slot twice with the same email.
- MINOR
The confirmation page has no booking ID.
To reproduce: Book any slot.
- MINOR
The "Made with Replit" badge overlaps the bottom of the screen on mobile.
To reproduce: Open the site at 390 px width.
- MINOR
One temporary 503 error after claiming the owner role; a retry worked.
Repro steps not recorded.
§05 Caveats
NoteTime is measured to the live URL (8 of 15). Counting the agent's 13-minute finish as the first working version would give 12 of 15 and a total of 87.625, which would rank Replit above Lovable (87.25, or 86.25 under review).
NoteDesign is a single tester's estimate.
NoteOwner login uses Replit's ready-made sign-in (Clerk), not the in-app email and password form the prompt asked for. No points were taken off for that.
NotePersistence after a redeploy and the second-owner security probe weren't tested.
NoteThe free published app stops running after 29 days unless upgraded.
All open questions: corrections log →
§06 Compare
Quick compare:vs Bolt.newvs Base44vs v0vs Lovablevs ChatGPT Codexvs Cursor
Visit Replit Agent (plain link, no affiliate code)
Lab notes by email
New results, retests and corrections, sent when there's something real to report. Nothing else.
Delivered with Kit's free plan. Unsubscribe from any email.



