VeriCoding (Z3): evidence, proof and selling tools

Official CAIN-42 IHVRK · New to this product? Learn it first

Don't trust CAIN-42. Verify CAIN-42. This is the Independent Human Verification Resource Kit for VeriCoding (Z3): every claim its page makes, as the exact request and the answer it must give, recorded live and signed. You check it on your own machine with a short Python script that uses no CAIN-42 code.

Every claim matched when recorded

Download the kit (.zip)

Everything you can give a customer

Selling tools

Pitch, emails, call script, objection answers, one-page summary, proposal.

Evidence pack

The figures and a ready email to an auditor or security reviewer.

Answers to buyer questions

Paste into a security questionnaire: YES, PARTIAL, NO or ASK.

Figures & benchmarks

Every number from the signed record, ready for a spreadsheet.

The kit

Kit	`vericoding-20261103T224738`
Recorded	2026-11-03T22:47:38+00:00 against cainstudio.online
Claims	7
Zip SHA-256	`664a2887d4cadf484411fe18e16eeee463708154afaf846414117fe2284658c0` (also in SHA256SUMS)
Signing key fingerprint	`1cacdfc1fc2024b6bb4f8fb02c7c80f4a57f44c5adb11c507190781b5d613de3`, published on cainstudio.online · mcpgate.online · clawx.click

Verify it on your own machine

unzip cain42-ihvrk-vericoding.zip && cd cain42-ihvrk-vericoding
python3 verify.py            # offline: hashes, Ed25519 signature, recorded answers
python3 verify.py --live     # also re-send every request yourself and check the answers now

A claim that cannot be checked counts as a FAIL, never a pass. The live check is the one that depends on nothing we recorded.

The claims in this kit

#	Claim	Answer must contain
C01	Sample: A discount that can make the price negative -> Z3 proves the contract or returns a concrete counterexample.	`[false]`
C02	Sample: max3 returns c instead of the true maximum -> Z3 proves the contract or returns a concrete counterexample.	`[false]`
C03	Sample: A clamp that returns lo + 1 for low inputs -> Z3 proves the contract or returns a concrete counterexample.	`[false]`
C04	Sample: An absolute value that returns x - 1 for non-negative x -> Z3 proves the contract or returns a concrete counterexample.	`[false]`
C05	Sample: A correct clamp (Z3 proves the contract already holds) -> Z3 proves the contract or returns a concrete counterexample.	`[true]`
C06	Your function: division that can divide by zero -> Undefined behaviour is never PROVED (the 2026-11-02 fuzzer found this case).	`[false]`
C07	Your function: honest max -> A correct function proves.	`[true]`

Evidence links you can give your customers

Kit download: /proof/bundle/ihvrk-kits/cain42-ihvrk-vericoding.zip
Each file on its own: README.txt · claims.json · transcript.json · MANIFEST.json · MANIFEST.sig · kit-key.json · verify.py
Run the live demo yourself on any of the three sites: cainstudio.online · mcpgate.online · clawx.click
The product explained: /top25-vericoding.html · what it does not do: limits
Signing key on three independent domains: cainstudio.online · mcpgate.online · clawx.click
Three ready-to-send evidence pages: 1. Evidence pack · 2. Answers to buyer questions · 3. Figures & benchmarks
Every kit: all IHVRKs · machine-readable index

Send this to your customer

Don't take our word for it. Verify VeriCoding (Z3) yourself:
1. Download the official CAIN-42 IHVRK: https://cainstudio.online/proof/bundle/ihvrk-kits/cain42-ihvrk-vericoding.zip
   SHA-256: 664a2887d4cadf484411fe18e16eeee463708154afaf846414117fe2284658c0
2. Unzip it and run: python3 verify.py --live   (Python 3, standard library only, no account)
3. Check the signing key fingerprint 1cacdfc1fc2024b6bb4f8fb02c7c80f4a57f44c5adb11c507190781b5d613de3
   matches https://cainstudio.online/evidence-kit-key.json, https://mcpgate.online/evidence-kit-key.json and https://clawx.click/evidence-kit-key.json
Live demo: https://cainstudio.online/top25-vericoding-lab.html
What it does not do: https://cainstudio.online/top25-vericoding-limits.html

What this kit is, and is not

It shows what the live product answered to these inputs, and lets anyone check that again. It is not a third-party audit, a certification, or a promise about inputs not listed. The product's limits page lists what it does not do.