01 / CANDIDATE
A system produces a structured claim.
For example: an extracted total, a constrained calculation, or a recovered sequence rule.
EXACT-OR-REFUSE EVIDENCE GATE
Check a machine claim.
Check a machine claim.
See exactly what it can prove.
Confidence is not evidence. Chiron checks the claims it can prove exactly, refutes what is false, and leaves everything outside that boundary explicitly uncertified.
Try a public, live licensed-engine check below — or use the sequence lab to see held-out proof in action.
live licensed engine
Check a claim from an AI output
Chiron extracts supported, exactly checkable claims and reports each one as VERIFIED, REFUTED, or REFUSED. Free-form remainder is never silently approved.
This calls the public demo endpoint. Do not send confidential or personal data.
Sequence lab — recover a rule, then test it on withheld terms
booting the engine…
Pick Fibonacci to watch it verify, or Primes to watch it refuse — the refusal is the point.
Why a refusal is the feature
A pass is useful only when the system can also say “not proven.”
01
It checks, not guesses
For supported claims, verdicts are exact. For sequences, a rule is stamped only when it predicts held-out terms it never saw — ==, not a tolerance.
02
It exposes the boundary
Fed the primes, it can recover a formula and still decline to stamp it. In claim checking, free-form remainder stays explicitly uncertified.
03
Its public proof is testable
The current frozen external eval has 22 stamped outputs, all 22 externally correct, 0 false stamps, and 12 refusals. Run it yourself →
What this becomes in a real workflow
Turn a supported check into a release condition.
Chiron is not an audit platform or a general answer judge. It is the small, inspectable gate a workflow can place around one independently checkable output.
02 / EXACT CHECK
Chiron checks only the supported boundary.
It verifies exact evidence, refutes a false supported claim, or leaves the rest explicitly uncertified.
03 / RECORD
Keep the verdict and coverage.
A machine-readable evidence record shows VERIFIED, REFUTED, or REFUSED and what was not covered.
04 / ROUTE
Release only what earned it.
A supported verified result can satisfy a defined gate. A refuted or refused result routes to the named human or wider review process.
How sure can you be — before paying?
Three depths of proof. Each says what it does and doesn't show.
The restraint is the brand — nothing here claims more than it proves.
10 SECONDS
This page
Try a non-sensitive claim with the live checker, or a sequence with the browser demo core.
Shows: the stated contract on one limited test input. The browser core is deliberately weaker than the licensed engine.
2 MINUTES
Grade it yourself
python3 eval/grade.py
The licensed engine's frozen outputs, graded live against oeis.org — data the author doesn't control.
Shows: 22 stamped / 22 externally correct / 0 false stamps / 12 refusals in the current frozen external eval. eval/ →
LIVE · THE REAL ENGINE
Hit the licensed engine
python3 eval/remote.py --url \
https://chiron-engine.onrender.com \
collapse "1 1 2 3 5 8 13 21"
The real engine over HTTP — certificate out, source never serialized, rate-limited.
Shows: the endpoint's contract on a limited input. It may refuse, rate-limit, or issue no certificate. endpoint →
Need this gate inside your workflow?Commercial access includes the full deterministic engine for organizational use, from $100/month.
What runs where, precisely
The claim checker and “licensed engine” sequence mode call the public HTTP demo. The browser sequence core is prototype/browser_core.py, fetched verbatim and run by CPython-in-WebAssembly. It is strictly weaker by design: five hypothesis families and a more conservative evidence rule. It refuses Catalan, factorials, and Tribonacci — which the licensed engine stamps (see eval/ and BATTERIES.md). The shared contract is narrower and more important: do not stamp what cannot be exactly supported.
Prove the discipline itself — run the architecture prototype's 26-gate battery, in this tab
prototype/primus_prototype.py enforces the membrane, the deterministic seal, the adjacency law — and a certifier stub that structurally cannot say VERIFIED (that's gate 26). This fetches the real file and runs its battery here.