Mass compare

mass-compare · version 1.0.0 · Units & sizes · free, no key needed

Compare two mixed-unit canonical integer mass amounts using exact nanogram BigInt values.

Use when you need to: mass compare · compare mass quantities · compare grams and pounds.

Supported

• mass compare
• compare mass quantities
• compare grams and pounds

Not supported

• sort a list of masses
• approximate or rounded compare
• locale unit names
• troy or stone units
• floating-point mass

Behavior

• left and right are objects with a canonical integer string value and a mass unit.
• Units are exactly ng, ug, mg, g, kg, t, oz, and lb; t is the metric tonne, lb is avoirdupois, oz is 1/16 lb.
• Each amount is converted to nanograms as BigInt; comparison is the numeric order of those nanogram values.
• cmp is the JSON integer -1, 0, or 1 according as left is less than, equal to, or greater than right.
• Negative amounts are allowed; -0 canonicalizes to 0.
• Unknown fields, unknown units, and non-canonical integers are rejected.

Input

• left (object, required)
• right (object, required)

Output

• cmp (one of -1, 0, 1, required)

Limits

• max digits: 1000

Example

Request input:

{
  "left": {
    "value": "1",
    "unit": "lb"
  },
  "right": {
    "value": "16",
    "unit": "oz"
  }
}

Response:

{
  "result": {
    "cmp": 0
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "mass-compare",
  "version": "1.0.0",
  "input": {
    "left": {
      "value": "1",
      "unit": "lb"
    },
    "right": {
      "value": "16",
      "unit": "oz"
    }
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/mass-compare/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"left":{"value":"1","unit":"lb"},"right":{"value":"16","unit":"oz"}}'

The machine-readable contract is at /v1/tools/mass-compare/versions/1.0.0.

CLI

node cli.mjs run mass-compare 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Mass convert: Convert a canonical integer mass amount between exact nanogram-based units as a reduced rational.
• Byte size compare: Compare two non-negative integer byte sizes by exact byte amounts.
• Mass add: Add mixed-unit canonical integer mass amounts and express the sum in a target unit as a reduced rational.
• Length compare: Compare two integer length measurements by exact nanometer amounts.
• Temperature compare: Compare two temperatures in C, F, or K by converting both to Kelvin rationals.
• Byte size add: Add non-negative integer byte-size terms in mixed IEC units and return the exact sum in a chosen unit.