`seq.sum`

An expression node, provided by Rulealize.Plugin.Sequence.

Form

{
  "op": "seq.sum",
  "source": <expression:Sequence>,
  "as": "<name>",            // optional
  "select": <expression:Number>   // optional
}

As the specification on the plugin's main branch writes it, read again on every run.

What it does is in that plugin's specification, which ships with the plugin and changes when it releases — read it.

dotnet add package Rulealize.Plugin.Sequence