The protocol
A number should be able to carry its evidence.
VCC is an experimental open protocol for portable, reproducible calculation receipts. It defines one chain — from the formula that runs to the receipt you can verify offline — and CalcFleet is its first reference implementation.
Why
Organizations keep the final number but lose the exact combination that produced it: the formula version, the normalized inputs, the source data, the rounding, the runtime, the issuer and the time. When the number is questioned months later, the calculation has to be rebuilt by hand from spreadsheets, logs, emails and old code. VCC preserves that evidence at the moment of calculation, so a receipt carries the formula, version, inputs, data, numeric rules, output, issuer and proof — and much of the reconstruction becomes a structured, automatable verification instead of an investigation.
What the protocol defines
One chain, five stages. Each stage is a fact the receipt records — not a feature bolted on afterwards.
- 1
Formula Library
Defines and versions the calculation rule. A formula is pinned by a deterministic package manifest, so “which formula, which version” is a fact, not a memory.
- 2
Execution
Runs the versioned formula on validated inputs — through a web tool, the REST API or MCP. The engine is deterministic: the same inputs and version produce the same outputs.
- 3
Issuance
Records the evidence as a VCC: the formula and version, the normalized inputs, the outputs with their units and rounding, the datasets, the issuer and the time — signed, so nothing can change after the fact.
- 4
Verification
Checks the receipt independently — authenticity, integrity and, when the formula resolves, reproduction. The result is never a single “verified” badge; each axis is reported on its own.
- 5
Governance
Keeps the protocol implementable by anyone: open licensing, a neutrality requirement, a decision process, and adoption gates so public claims only escalate when they are earned.
What a receipt records
The specification defines the pieces a VCC can carry. In plain language: the data model (what is in the statement), the assurance model (the axes a verifier reports separately), numeric profiles (how values are typed and rounded), formula packages and dataset manifests (how “which rule” and “which data” are pinned), the proof envelope (the signature), privacy profiles, the trust model, conformance and governance.
Where it stands
Public claims escalate only when objective gates are met. We are at the first one, and we say so.
- ExperimentalCurrent“experimental open protocol”
- Interoperable“interoperable open protocol”
- Pilot-ready“being piloted in real business workflows”
- Standardization candidate“candidate for broader standardization”
We do not use “standard” as a fait accompli. See governance for the full gate criteria and the decision process behind them.
A VCC proves the integrity, provenance and — when reproducible — the technical repeatability of a deterministic calculation. It does not assert that the inputs are true, that a formula fits a particular purpose, or that a result constitutes professional advice or a regulatory certification.