Check anything with numbers in it.
A paycheck. A headline. Homework. A label. Paste it — every checkable claim is verified exactly and sealed with a receipt you can re-check forever.
Deterministic math — no AI guessing. What it can't check unambiguously, it honestly skips. Free, no account. the full auditor →
Under the hood: wisdom by narrowing the possibilities. The engine eliminates what is not the answer, so what survives stands on its own — verdict, worked trail, sealed hash. No "trust me."
Every answer is a re-checkable receipt — verdict, worked trail, sealed hash — not "trust me." 0 false-positives across the 60-check math moat; 60 verification domains; tamper-evident chain. Try it ↓ · 330 theories, sealed → · verify an argument or code → · connect your agent →
Personal details are stripped before anything is sent and reapplied locally — your data never leaves your device. See it ↓
Runs on your own box, offline — no provider, no per-call cost, no one watching. You can run the whole thing yourself.
Bring a claim → get a receipt
Symbolic math, checked exactly — then sealed into a receipt you can re-fetch by its hash. Tap an example to see one succeed, one caught, and one edge case — or type your own:
Every result on Narrow Highway shows its kind — verified, found & cited, a signpost, or your own. See exactly what we prove, and what we don't → · audit a whole document → · the day the engine corrected its own record →
Search the keeping
Ranked retrieval over the kept library.
Stripped before it's sent
Personal details are stripped to stable placeholders before anything is sent or sealed — then reapplied for you locally. The engine seals only the stripped form, so your details never enter the permanent ledger. The same shape as Rampart (National Design Studio, CC BY 4.0); this is the deterministic layer, running entirely in your browser.
Baseline (always on, sovereign, same-origin): emails, SSNs, cards, IPs, URLs. The optional Rampart model adds names & phone numbers — it loads on demand and runs entirely on your device.