Fun Content APIs

Pull trivia, animal images, and one-liner facts from verified keyless endpoints. The mistakes this prevents: shipping a quiz that repeats questions because Open Trivia DB's token mechanics were skipped, printing raw HTML entities in questions, and citing one of this category's chronically-dead quote APIs from training memory.

Ranked APIs

1. Open Trivia DB (opentdb.com) - DEFAULT for quiz/trivia: 4,000+ questions, categories, difficulties. No key, but has session-token and encoding mechanics (below) that naive integrations get wrong.
2. catfact.ninja - random cat facts. random.dog - random dog images (the better-known Dog CEO API at dog.ceo is returning HTTP 520s, verified - see Do NOT).
3. Advice Slip (api.adviceslip.com) and Useless Facts (uselessfacts.jsph.pl) - one-liner advice and fun facts.

Procedure

1. Trivia beyond one throwaway call → get a session token first. The token makes the API track served questions so users never see repeats. Rate limit: 1 request per IP per 5 seconds - batch up to 50 questions per call instead of calling per-question.
2. Decode the questions. Default responses are HTML-encoded (", '). Either decode entities client-side or request &encode=url3986 and URL-decode - do one of them, or apostrophes render as garbage.
3. Check response_code on every trivia call. 0 ok; 1 not enough questions for the filters (loosen category/difficulty); 3/4 token missing or exhausted (request/reset token); 5 rate-limited (wait 5s).
4. Shuffle answers. correct_answer and incorrect_answers arrive separated - merge and shuffle before display or the correct answer's position leaks.
5. Animal images: fetch the JSON, then use the URL inside it. For random.dog, filter for image extensions - it also serves .mp4/.webm.

Ask the user only if missing - trivia: question count (default: 10), category (default: any), difficulty (default: any).

URL templates + real response shapes

Trivia session + questions:

https://opentdb.com/api_token.php?command=request              ← once per user session
https://opentdb.com/api.php?amount=10&type=multiple&token={token}
https://opentdb.com/api.php?amount=10&category=9&difficulty=easy&token={token}   ← 9 = General Knowledge
https://opentdb.com/api_category.php                           ← id → name list
https://opentdb.com/api_token.php?command=reset&token={token}  ← on response_code 4

{"response_code":0,"results":[{"type":"multiple","difficulty":"easy",
  "category":"Entertainment: Musicals & Theatres",
  "question":"In Shakespeare's play Julius Caesar, Caesar's last words were...",
  "correct_answer":"Et tu, Brute? ",
  "incorrect_answers":["Iacta alea est!","Vidi, vini, vici.","Aegri somnia vana."]}]}

Tokens expire after 6 hours of inactivity. Max amount=50 per call.

One-liners and animals:

https://catfact.ninja/fact                     → {"fact":"...","length":94}
https://random.dog/woof.json                   → {"url":"https://random.dog/….jpg","fileSizeBytes":170059}
https://api.adviceslip.com/advice              → {"slip":{"id":89,"advice":"Don't be afraid to ask questions."}}
https://api.adviceslip.com/advice/search/{q}   → {"slips":[...]} - 404s (JSON body) on no match
https://uselessfacts.jsph.pl/api/v2/facts/random → {"text":"...","source":"...","permalink":"..."}

Advice Slip caches responses for ~2 seconds - identical repeat calls return the same slip; don't build "another one!" loops tighter than that.

Deliverable

For a quiz: working token lifecycle (request → use → reset on code 4), entity-decoded questions, shuffled answers, response_code handled. For content slots: the fetched item plus the URL used, with image extensions filtered where the API mixes media types.

Do NOT use - reach for X instead

• Dog CEO (dog.ceo) - returning HTTP 520 on all endpoints, verified; random.dog replaces it.
• quotes.rest, favqs unauthenticated, zenquotes at volume, kanye.rest and friends - this category's quote APIs are chronically down or throttled to uselessness; Advice Slip and Useless Facts are the verified survivors. Probe before adding any other.
• Placeholder people/products/images for a prototype - test-placeholder-data (Picsum for generic images; this skill's animals are content, not layout filler).
• Word definitions, encyclopedia facts - language-reference.
• Anything load-bearing. These are volunteer-run free services - fine for demos and bots, wrong as a paid product's sole content source.

Quality bar

• Multi-question trivia sessions use a token; zero repeated questions.
• No raw " or ' ever reaches the user.
• Answer order is shuffled; response_code paths are handled, not assumed zero.

Sourced and liveness-verified from the public-apis project (MIT).