Source: https://guthlabs.ai/docs/instruments/recipe-scaler/implementation/

instrument implementation / implementation-contract

# Recipe Scaler implementation

A source-bound implementation contract for Recipe Scaler; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t2-007

**Effect**: Computation or source lookup only

## Input and validation requirements

The specification exposes two hazardous gaps: zero original yield has an undefined result and requires explicit rejection, while mixed or missing dimension-unit conventions can change a valid pan-area result from approximately 1.94 cups to 12.5 cups. Non-linear ingredient adjustments also remain heuristic rather than exact.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "mode": "yield",
    "ingredients": [
      {
        "name": "flour",
        "old_qty": 300,
        "unit": "g"
      },
      {
        "name": "milk",
        "old_qty": 240,
        "unit": "ml"
      },
      {
        "name": "eggs",
        "old_qty": 2,
        "unit": "each"
      },
      {
        "name": "salt",
        "old_qty": 5,
        "unit": "g"
      }
    ],
    "original_yield": 4,
    "target_yield": 6
  },
  "expected_outputs": {
    "scaled_ingredients": [
      {
        "name": "flour",
        "qty": 450,
        "unit": "g"
      },
      {
        "name": "milk",
        "qty": 360,
        "unit": "ml"
      },
      {
        "name": "eggs",
        "qty": 3,
        "unit": "each"
      },
      {
        "name": "salt",
        "qty": 7.5,
        "unit": "g"
      }
    ],
    "warning_flags": [
      "salt is non-linear and should be reviewed as a heuristic estimate"
    ]
  },
  "working": "Factor = target_yield/original_yield = 6/4 = 1.5. Flour: 300 × 1.5 = 450 g. Milk: 240 × 1.5 = 360 ml. Eggs: 2 × 1.5 = 3 each. Salt: 5 × 1.5 = 7.5 g."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/recipe-scaler/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/recipe-scaler/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/recipe-scaler/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche2/tranche2-results.json`