Independent verification

Check a LEXUN result without trusting LEXUN.

Every forecast the platform produces can be exported as a sealed receipt, or as a full .lexun package containing the frozen inputs, the random seed, the model version and the audit record. Paste one below and this page will check it — in your browser, using the same engine code the platform runs, with nothing sent to us or to anyone else.

Three separate questions, answered separately. A verifier that collapses everything into one green tick is hiding something, because these can disagree. This page tells you which of the three passed: whether the seal matches the contents, whether the audit record is unaltered, and whether an independent re-run of the model reproduces the same number.

Paste a receipt or a package

Receipt JSON, or a whole .lexun package

Read locally by your browser. Not uploaded.

The sample is not a stored file — pressing “Load a live sample” runs the real runway engine in your browser right now and packages the result, so what you verify is produced by the shipping code.

What each check actually proves

Check	Proves	Does not prove
Seal	The receipt says exactly what it said when it was written. One changed digit anywhere — a probability, a date, the resolution criterion — changes the SHA-256 hash.	When it was written, or who wrote it. There is no timestamping authority and no signature, because there are no accounts.
Audit record	Each event in the record still carries its original contents, and in the full record on the device each event is chained to the one before it by hash, so no entry can be quietly altered in the middle.	That nothing was ever deleted. A hash chain cannot prove the absence of something that was removed from the end, and the owner of the device can always start a fresh record.
Independent re-run	The number is real. Your browser runs the named model at the named seed over the frozen inputs and reaches the same probability, digit for digit.	That the inputs were true. The model is reproducible; the assumptions fed into it are the user's, and the package labels which fields were facts and which were assumptions.

Why this page exists

The comparable products in this category publish accuracy figures and no method. We think that is the wrong way round: a number you cannot check is a marketing claim, and a method you can check is a product. So the verification is not a diagram of a process we run internally — it is this page, running on your machine, on a file you hold.

The honest limits are stated above and repeated in the receipt itself. It is a content hash and an audit chain: tamper-evident, not tamper-proof. That distinction matters, so we print it rather than hiding behind the word "cryptographic". More on the whole approach on the defensibility page, the Trust Centre and the reproduction guide.