Checkpoint!
Free · play online in your browser, no download
An airport security queue sim where you shape the space, not the passengers: rope barriers, gates, lanes and a concourse mall. The developer says it was built with Claude Fable in one context window.
Official site yaodub.com, verified Nov 3, 2026. Hosted on the developer's own website (yaodub.com, Games section) and linked from the developer's Show HN post.
Where to play
Every platform this game is on. Links are checked against official sources; we never host or mirror games.
- Play free — official siteBrowserReleasedFree
Runs in a desktop browser. No download.
Browser (no download) · Official link verified Nov 3, 2026.
- View on GitHubGitHubReleased · Source code (MIT)Free
Source code repository, not a place to play.
Official link verified Nov 3, 2026.
About Checkpoint!
Checkpoint! is a free airport security queue simulation for the browser. You never control the passengers; you design the floor they walk through, with rope barriers, belt gates, checkpoint lanes and a concourse mall, and pixel travellers find their own way through it. Passengers grow frustrated while standing still and hardly at all while walking, and faster still in a crowd, so a long snaking line keeps people calm while a shapeless crowd turns angry and people walk off; the scanners work at the same speed either way. Arrivals come in waves, each sized to test the next thing you can afford. Each served passenger pays a flat $5 and each walk-off costs $25 and upsets everyone nearby; the money buys fences, gates, up to six checkpoints with lane upgrades, and six mall shops, from a coffee kiosk to duty-free, where visitors spend money, regain patience and pick up perks. Each wave's first arrival is a VIP worth a bonus, and you lose by ending a wave bankrupt or by letting too much of one wave storm off. The developer, yaodub, posted it on Hacker News in June 2026 as an experiment with Claude Fable, which had just come out, saying the whole thing came together in one context window. Free in the browser; the source is under the MIT licence.
How it was built
Partially verifiedThe developer's Show HN post (11 Jun 2026, UTC) is titled “Checkpoint! Airport security sim game built with Claude Fable” and reads: “Fable just came out and I wanted to see what it was actually capable of.” It ends: “Whole thing came together in one context window. I'm impressed.” The post does not say which Claude product the model was used in, and gives no code share. The repository and the game page do not mention AI.
Built with Claude Fable within a single context window, per the developer's post. The game is a TypeScript and Canvas app built with Vite (about 64 KB, per the developer's site); its pathfinding treats people as obstacles with costs, so walking behind someone going the same way is cheap and pushing against a line is expensive. The repository also holds scripts for simulating, sweeping and auditing waves and paths. The public repository has a single commit, dated 11 Jun 2026.
- Engine / framework
- None (TypeScript with Vite and Canvas 2D)
- Languages
- TypeScript
- Team size
- Not disclosed
- Initial build time
- Not disclosed
- Development time
- Not disclosed
- Development cost
- Not disclosed
- AI-written code
- Not disclosed
“Whole thing came together in one context window. I'm impressed.”Verification notes: AI use from the Show HN post by yaodub (11 Jun 2026, 17:24 UTC), read through the Hacker News API on 7 Nov 2026. “Built with Claude Fable … Whole thing came together in one context window” is read as Claude writing the game, with medium confidence; the post does not say in those words that Claude wrote the code, and gives no share, so none is recorded. The repository and the game page do not mention AI. Rules, prices and controls come from the README of yaodub/checkpoint and the live page, read on 7 Nov 2026; the repository's single commit (11 Jun 2026, 06:24 UTC) and the Show HN date give the release date. The game's script contacts no outside services. The developer gives no name beyond the handle and the “Yao” signature on the website. The game was not played.
Development history
Source published on GitHub in a single commit (06:24 UTC), and the game shared as a Show HN, built with Claude Fable (17:24 UTC).
Game performance
Each figure measures something different — concurrent players, owners, downloads and sales are never interchangeable and are never added together. Labels show where each number comes from.
Browser (official site)
Free in the browser, with no account.
No public metrics recorded for this listing.
Not publicly available: Concurrent players (site), Monthly revenue, Gross revenue.
GitHub
No public metrics recorded for this listing.
Not publicly available: GitHub stars.
Sales & revenue (all platforms)
Browser game — there are no downloads to count.
Reviews & rankings
Not yet reviewed by our editors.
Not currently ranked.
Sources
| Source | Type | Published | Accessed |
|---|---|---|---|
| Show HN: Checkpoint! Airport security sim game built with Claude Fable Hacker News (yaodub) | Social post | Jun 11, 2026 | Nov 3, 2026 |
| Checkpoint! — airport security queue sim yaodub | Official site | Not confirmed | Nov 3, 2026 |
| checkpoint README: Checkpoint! GitHub (yaodub) | Repository | Jun 11, 2026 | Nov 3, 2026 |
| yaodub yaodub | Official site | Not confirmed | Nov 3, 2026 |
| Official game page (language check) yaodub | Official site | Not confirmed | Nov 3, 2026 |
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