Matrix multiply

matrix-multiply · version 1.0.0 · Vectors & matrices · free, no key needed

Multiply an MxK finite-number matrix by a KxN finite-number matrix, producing an MxN matrix.

Use when you need to: matrix multiplication · matrix product · multiply two matrices.

Supported

• matrix multiplication
• matrix product
• multiply two matrices

Not supported

• elementwise multiplication (use matrix-hadamard)
• incompatible inner dimensions
• sparse matrix representation

Behavior

• Input a is an MxK matrix and b is a KxN matrix of finite JSON numbers; a columns must equal b rows. M, K, N are each from 1 to 20.
• Each entry magnitude is bounded to at most 1000000 before multiplication.
• The result is the standard MxN matrix product, result[r][c] = sum over k of a[r][k] * b[k][c], accumulated left-to-right in IEEE-754 double precision.
• A result entry of -0 is normalized to 0.

Input

• a (array of array of number, required): min items 1; max items 20
• b (array of array of number, required): min items 1; max items 20

Output

• result (array of array of number, required)

Limits

• max dim: 20
• max abs value: 1000000

Example

Request input:

{
  "a": [
    [
      1,
      2
    ],
    [
      3,
      4
    ]
  ],
  "b": [
    [
      5,
      6
    ],
    [
      7,
      8
    ]
  ]
}

Response:

{
  "result": {
    "result": [
      [
        19,
        22
      ],
      [
        43,
        50
      ]
    ]
  }
}

How to call it

MCP

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

{
  "id": "matrix-multiply",
  "version": "1.0.0",
  "input": {
    "a": [
      [
        1,
        2
      ],
      [
        3,
        4
      ]
    ],
    "b": [
      [
        5,
        6
      ],
      [
        7,
        8
      ]
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/matrix-multiply/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"a":[[1,2],[3,4]],"b":[[5,6],[7,8]]}'

The machine-readable contract is at /v1/tools/matrix-multiply/versions/1.0.0.

CLI

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

Get the client at /clients/cli/.

Related tools

• Matrix hadamard: Multiply two equal-shape finite-number matrices elementwise (Hadamard product).
• Matrix vector multiply: Multiply an MxN finite-number matrix by a length-N finite-number vector, producing a length-M vector.
• Vector outer product: Compute the outer product of two finite-number vectors, producing a matrix.
• Matrix scale: Multiply every entry of a finite-number matrix by a scalar.
• Vector dot: Compute the dot (scalar) product of two equal-length finite-number vectors.
• Vector hadamard: Multiply two equal-length finite-number vectors elementwise (Hadamard product).