# Integer multiply

`integer-multiply` · version 1.0.0 · Numbers & math · free, no key needed

Multiply two canonical base-10 integer strings and return their product.

**Use when you need to: integer multiply · multiply two integers · integer product.**

## Supported

- integer multiply
- multiply two integers
- integer product

## Not supported

- integer add
- integer division
- floating point multiply
- hexadecimal integers
- scientific notation

## Behavior

- Inputs a and b are canonical base-10 integer strings, except that -0 is accepted and canonicalized to 0.
- Integers are parsed with BigInt; IEEE-754 numbers are rejected.
- The output value is the canonical integer string of the product a * b.
- Each input and the product may have at most 1000 digits excluding sign; overflow is invalid_input.
- Leading zeros, plus signs, spaces, underscores, hex, and scientific notation are rejected.

## Input

- `a` (string, required): min length 1; max length 1001
- `b` (string, required): min length 1; max length 1001

## Output

- `value` (string, required): min length 1; max length 1001

## Limits

- max digits: 1000

## Example

Request input:

```json
{
  "a": "12",
  "b": "13"
}
```

Response:

```json
{
  "result": {
    "value": "156"
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "integer-multiply",
  "version": "1.0.0",
  "input": {
    "a": "12",
    "b": "13"
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/integer-multiply/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"a":"12","b":"13"}'
```

The machine-readable contract is at [/v1/tools/integer-multiply/versions/1.0.0](/v1/tools/integer-multiply/versions/1.0.0).

### CLI

```sh
node cli.mjs run integer-multiply 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [Array integer product](/tools/array-integer-product): Multiply an array of canonical integer strings and return the canonical product.
- [Integer add](/tools/integer-add): Add two canonical signed integer strings and return their canonical sum.
- [Integer GCD](/tools/integer-gcd): Compute the non-negative greatest common divisor of two canonical integer strings.
- [Integer LCM](/tools/integer-lcm): Compute the non-negative least common multiple of two canonical integer strings.
- [Rational multiply](/tools/rational-multiply): Multiply two rational numbers given as numerator/denominator integer strings and return the reduced product.
- [Array integer GCD](/tools/array-integer-gcd): Compute the non-negative greatest common divisor of an array of canonical integer strings.