New · proof layer
VCC — Verifiable
Calculation Certificates.
A VCC turns a calculation into a cryptographic receipt that proves what was calculated, how, and with which data — and that anyone can check, even offline, without trusting this site.
What a VCC proves
- who issued the certificate (Ed25519 signature + published keys)
- which formula and version ran (manifest digest)
- which validated inputs were used
- which outputs were produced, with declared units and rounding
- which versioned datasets were consumed
- that nothing changed after signing (content-addressed statement)
- when possible, that re-running the formula reproduces the outputs
What it deliberately does not prove
- that the inputs are true
- that the formula is legally or economically appropriate for your purpose
- that the result is advice, a decision, or a professional opinion
- regulatory compliance of any kind
- that a valid signature equals an independent audit
That is why verification reports four separate axes — authentic, intact, reproducible, trusted — and never a single “verified” stamp.
How it works
From calculation to checkable proof.
Deterministic execution — your validated inputs run through a pure, versioned formula.
Canonical statement — inputs, outputs, formula digest and datasets — one unambiguous JSON (RFC 8785).
Content-addressed id — the certificate id is the hash of its own content: change a byte, change the id.
Signature — Ed25519 over a DSSE envelope, with the issuer keys published at a well-known URL.
Independent verification — anyone re-checks signature and integrity offline; formulas in the open registry can be re-run and diffed.
For AI agents
An agent that quotes a number can attach proof of where it came from — formula, version, inputs — instead of asking you to trust the transcript.
For software
Log the certificate, not a screenshot. Any pipeline can re-verify results years later, offline, byte for byte.
For compliance-minded teams
Integrity and reproducibility become checkable properties. What a VCC does not prove is stated just as clearly.
Rollout status — honest edition
VCC is live as a pilot on 3 formulas (personal-loan, compound-interest, home-affordability), behind an explicit certify flag on the API and MCP. The certificate format, test vectors and threat model are public in the repository docs; the rest of the fleet migrates formula by formula.
A certificate demonstrates the integrity, provenance and — when available — the technical reproducibility of a calculation. It does not prove that inputs are true, that a formula fits a specific purpose, or that a result constitutes professional advice or a regulatory certification.