70IQ 🧠

Source: https://github.com/ijat/70IQ

A fast, fun, culture-fair IQ test. Adaptive non-verbal reasoning puzzles (matrices, sequences, mental rotation, odd-one-out, analogies), an honest estimated score with a range + percentile, slick animations, sound effects, light/dark that follows the system — and a JSON API so AI agents can take the same test.

Built with Next.js (App Router) + TypeScript + Tailwind + Motion. Deploys to Vercel with zero config.

How it scores

• Procedurally generated items (SVG for humans, text encoding for LLMs), so the bank is effectively infinite and hard to memorise. Difficulty follows the Carpenter/Just/Shell (1990) matrix rule taxonomy.
• Adaptive (CAT): 2-parameter-logistic IRT with maximum-Fisher-information item selection and EAP ability estimation (src/lib/irt.ts).
• Ability θ → IQ via 100 + 15·θ, percentile from the normal CDF. The result is shown as a range because every test has measurement error.
• It's a well-grounded estimate, not a clinical assessment.

Privacy

Everything runs and is scored in the browser. Results live only in localStorage for the history viewer — never uploaded or used for training.

Develop

npm install
npm run dev      # http://localhost:3000
npm run build    # production build

Deploy to Vercel

Push to a Git repo and import it at vercel.com/new, or:

npm i -g vercel
vercel

Optional env var: IQ_SECRET — HMAC secret used to sign the stateless LLM session tokens (any random string; defaults to a dev value).

AI agents

See /llms.txt once deployed (served at https://<your-domain>/llms.txt). Flow:

1. POST /api/iq/start { "mode": "quick" } → { session, question }
2. POST /api/iq/answer { session, answer: "B" } → next question, repeat
3. when done: true, read result (iq, range, percentile, cognitive profile)

The session is a signed, stateless token — no database required.

Project map

src/lib/irt.ts            2PL IRT + EAP + θ→IQ
src/lib/engine.ts         adaptive loop + result (shared by UI and API)
src/lib/scoring.ts        meme bands + cognitive profile
src/lib/questions/*       procedural generators (matrix, sequence, rotation, …)
src/lib/session-token.ts  signed stateless sessions for the API
src/components/*          Landing, TestRunner, ResultView, History
src/app/api/iq/*          LLM endpoints
src/app/llms.txt          agent instructions