Open calculation evidence

Make important calculations provable.

A number is not enough — you need to know how it was calculated. CalcFleet executes versioned formulas and issues portable VCC receipts showing the inputs, rules, sources and outputs behind each result.

See a real VCC Try the proof test

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The problem

A result without evidence creates friction.

Companies keep the final number but lose the exact combination that produced it — the formula, its version, the inputs and the data. When the result is questioned months later, the calculation has to be reconstructed by hand.

Disputed commission

What happened
A rep contests a payout months later. The spreadsheet that produced it has since changed.
Why the current evidence fails
Screenshots and email threads can't prove which formula, tiers and inputs actually ran that quarter.
What VCC adds
A receipt that pins the exact formula version, inputs and result — reproducible on demand.

Unexplained quote

What happened
A customer asks how a price was reached. The person who built the model has left.
Why the current evidence fails
The quote is a number in a PDF; the rules and source data behind it live in nobody's memory.
What VCC adds
The evidence travels with the number: the rule, the inputs, the data vintage and the output.

AI-generated financial answer

What happened
An assistant returns a figure inside a workflow that acts on it. Later, someone has to defend it.
Why the current evidence fails
A chat transcript shows the answer, not a checkable record of how the math was actually done.
What VCC adds
CalcFleet does the calculation deterministically and issues a receipt the answer can carry.

Before & after

From scattered evidence to a receipt.

Before

Evidence scattered across tools.

  • Spreadsheet
  • Screenshot
  • Email
  • Application log
  • Manual explanation

After

Evidence the number carries with itself.

  • Versioned formula
  • Normalized inputs
  • Deterministic output
  • Signed receipt
  • Independent verification

A worked example

A commission you can defend.

A tiered commission runs as a versioned formula. The VCC records exactly what produced the payout, so the figure can be checked independently later.

Formula

tiered_commission · 1.2.0
Contract
Sales Commission 2026
Revenue
$84,300
Tier 1
5%
Tier 2
7%
Adjustment
−$250
Result$5,151

VCC receipt

Illustrative example

  • Formula resolved

    tiered_commission, version 1.2.0 — the exact rule used.

  • Inputs intact

    Revenue and tiers recorded byte-for-byte.

  • Signature valid

    Signed by the declared key, unaltered since.

  • Key active

    The signing key was in force at issue time.

  • Result reproduced

    Re-running the formula returns $5,151.

See the real commission VCC, end to end

AI interprets.
CalcFleet calculates.
VCC provides the evidence.

How it works

Define. Execute. Issue. Verify.

  1. Define

    A calculation is a versioned formula with declared rules — not a cell in someone's spreadsheet.

  2. Execute

    Run it deterministically through the web tools, the REST API or an MCP tool for AI agents.

  3. Issue

    CalcFleet issues a portable VCC receipt: the formula, version, inputs, data and output.

  4. Verify

    Anyone can check the receipt independently — signature, integrity and reproduction, separately.

Infrastructure

One engine, from formula to proof.

Read the developer docs

Open protocol

A receipt anyone can check.

VCC is an experimental open protocol — public specification, public schemas, an open-source verifier, published test vectors and documented governance. CalcFleet is its first reference implementation, not its owner.

Explore the protocol Read the specification
  • Public specification
  • Public schemas
  • Open-source verifier
  • Published test vectors
  • Documented governance
  • Status: experimental

Bring us one calculation that is difficult to explain.

We will model it as a versioned formula and show how a VCC can make the result portable and reproducible.

Start a pilot See a real VCC