Where the content comes from
Nothing in these games is hosted here. The repository holds lists — titles, artist names, article ids, emoji, quotations, ingredients — and the media is fetched from its source when a round is dealt. This page says exactly which source each game uses and what that means in practice.
All four sources are public and keyless. That is a constraint the project set itself, and it shaped the games as much as any design decision did.
iTunes Search API
Guess the Song and Guess the App. The song game uses the 30-second preview clips the API serves; the app game uses the 512-pixel icon from the same catalog.
Two things about that API shape how the games work. It indexes the store rather than the history of recorded music, so searches return karaoke versions, lullaby records, string-quartet tributes and 8-bit covers alongside the real thing, and anything matching that pattern is discarded before it can become a round. And it rate-limits by IP, answering 403 without CORS headers when you exceed it — from JavaScript that is indistinguishable from being offline — so requests go through a token bucket that allows a burst of 14 and a sustained 18 per minute.
Wikipedia and Wikimedia Commons
Seventeen of the games load images from Wikipedia's REST summary endpoint: animals, birds, insects, plants, objects, landmarks, cities, dishes, sports, cars, celebrities, logos, country maps, video game covers, board game boxes and release-year posters, plus the four portraits in the quote game. Every one of those pictures is credited under the answer once a round is over, linking to the file it came from.
Wikimedia serves only pre-rendered thumbnail widths. Probing a single file, 250, 330, 500, 1280, 1920 and 3840 pixels returned images and every other width returned HTTP 400 — so stage images ask for 1280, which is about a fifth of the bytes of a typical original, and fall back to the original for files that width was never cached for. Requests are queued at three in flight, because Wikipedia starts returning 429 at around eight.
Not everything Wikipedia hosts is free to reuse, and the distinction is visible in the URL: files under upload.wikimedia.org/wikipedia/commons are freely licensed or public domain, while files under /wikipedia/en are local uploads carried under English Wikipedia's own fair-use rationale, which covers an encyclopedia and not an ad-supported game. The logo deck is filtered on exactly that test and lost sixteen brands to it. Film posters, game covers and board game boxes are the low-resolution non-free files, used in a quiz — the same shape of use as the encyclopedia's, but fair use rather than a licence, and the piece to revisit if this were ever run commercially at scale. Logos are shown as published and unaltered apart from the reveal; naming a brand from its mark is nominative use and implies no endorsement. Photographs used for the home page card art carry their licence and author in the photo credits panel on the home page, because CC-BY and CC-BY-SA require the attribution to be visible.
YouTube
Guess the Movie plays one to fifteen seconds of a trailer through an embedded player. Guess the TV Show plays a theme tune through the same mechanism with the picture hidden, because opening titles print the show's name on screen within the first few seconds.
Both games work around the embed rather than against it. Captions are disabled, since auto-showing subtitles print the dialogue. The film game covers the player whenever it is not actively rendering video, because a paused frame hands over more of the film than the player paid for and YouTube's title bar would simply print the answer. The theme-tune game rewrites the iframe's title attribute, which the embed API otherwise sets to the name of the video — that is, to the answer.
Google Street View
Guess the Country uses Google's iframe embed, which needs no API key but only renders when it is genuinely inside an iframe. The 55 coordinates were each loaded through it and confirmed to return official Street View car imagery rather than a user-uploaded photosphere, which is a real problem otherwise: plenty of places with no car coverage still return something, often shot indoors or from a hotel balcony.
The embed prints the place name in its top-left corner, which is the answer, so that corner is covered. Google's logo, the Terms link and the imagery attribution along the bottom are left completely visible and interactive. Covering a place label is fine; hiding attribution is not.
Written by hand
Eleven games need no network at all, because their content is written into the site rather than fetched. The emoji rebuses, the film lines, the novel openings, the flat plot summaries, the advertising slogans, the language sentences, the capitals, the word definitions, the ingredient lists and the quotations are all bundled.
Those files were the slowest part of the project and the ones with the strictest rules: no invented recipes, no misattributed quotations, no slogans whose attribution was uncertain, no language sentence that a speaker would not write. Where something could not be confirmed it was left out rather than guessed at, which is why several decks are shorter than they could have been.