curl --request POST \
  --url https://api.iotools.cloud/v1/tool/divergence-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "p": "x^2*y",
  "q": "y*z",
  "r": "x*z^2",
  "x": "1",
  "y": "2",
  "z": "3"
}
'

{
  "tool": "divergence-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "divergenceValue": "13",
    "divergenceExpression": "z * (2 * x + 1) + 2 * y * x",
    "classification": "div F > 0 at this point — a net source (outward flux)",
    "steps": "F(x, y, z) = (x^2*y, y*z, x*z^2)\n∂P/∂x = 2 * y * x\n∂Q/∂y = z\n∂R/∂z = 2 * x * z\ndiv F = ∂P/∂x + ∂Q/∂y + ∂R/∂z\n      = z * (2 * x + 1) + 2 * y * x\nAt (x, y, z) = (1, 2, 3):\ndiv F = 13"
  },
  "credits_used": 5,
  "credits_remaining": null
}