Decimal add

decimal-add · version 1.0.0 · Numbers & math · free, no key needed

Exact decimal addition of canonicalizable decimal strings.

Use when you need to: decimal add · add decimals · exact decimal sum.

Supported

• decimal add
• add decimals
• exact decimal sum

Not supported

• ieee754
• currency rounding
• tax
• interest

Behavior

• Input decimal strings: /^-?(0|[1-9][0-9]*)(\.[0-9]+)?$/.
• Reject leading zeros, plus signs, spaces, exponents, bare ".", trailing ".", empty, and NaN/Infinity tokens.
• At most 40 digits excluding sign and decimal point. At most 18 fractional digits on input.
• Canonicalize: strip trailing fractional zeros; drop the decimal point if the fraction vanishes; normalize -0 and -0.0 to "0".
• Exact decimal arithmetic with BigInt scaled integers. No IEEE-754 intermediates. Never return JSON BigInt.
• Return canonical sum. Intermediate scale is the max of operand scales, then canonicalize.

Input

• a (string, required): min length 1; max length 44
• b (string, required): min length 1; max length 44

Output

• value (string, required)

Limits

• max digits: 40
• max scale: 18

Example

Request input:

{
  "a": "1.50",
  "b": "0.5"
}

Response:

{
  "result": {
    "value": "2"
  }
}

How to call it

MCP

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

{
  "id": "decimal-add",
  "version": "1.0.0",
  "input": {
    "a": "1.50",
    "b": "0.5"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/decimal-add/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"a":"1.50","b":"0.5"}'

The machine-readable contract is at /v1/tools/decimal-add/versions/1.0.0.

CLI

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

Get the client at /clients/cli/.

Related tools

• Decimal subtract: Exact decimal subtraction a minus b of canonicalizable decimal strings.
• Array rational sum: Sum an array of canonical rationals and return the reduced total.
• Decimal compare: Compare two decimal strings exactly after canonicalization.
• Integer add: Add two canonical signed integer strings and return their canonical sum.
• Rational add: Add two rational numbers given as numerator/denominator integer strings and return the reduced sum.
• Array integer cumulative sum: Replace an array of canonical integer strings with equal-length prefix sums.