---
title: "DriverNode"
description: "one node of a value driver tree: a leaf that a party states, or a formula over its children"
section: concepts
address: /concepts/drivernode
contract: 0476e35e6e275db5
---

# DriverNode

one node of a value driver tree: a leaf that a party states, or a formula over its children

[figure: DriverNode is a value at none scope. The drawing shows its fields and the objects that they point at.]

| property | value |
|---|---|
| kind | value |
| scope | none |
| key | one node of a driver tree |
| store | none |
| family | market |



## Fields


| field | type | required | note |
|---|---|---|---|
| `driver` | [KindOfMeasure](/concepts/kindofmeasure) | yes | the value driver this node produces, a kind of measure of the economics family |
| `operator` | `one of leaf \| add \| subtract \| multiply \| divide \| minimum \| maximum \| constant \| share of \| per period \| clamp` | yes | leaf for a stated, read or benchmarked input; the rest are the closed operators the one evaluator computes |
| `children` | [DriverNode](/concepts/drivernode) | no | the operands, in order; empty for a leaf |
| `constant` | `json` | no | the value of a constant node, with the dimension below |
| `dimension` | `text` | yes | the dimension the node produces, which the evaluator checks follows from its children |
| `stated_by` | `one of the buyer \| a benchmark \| the record \| a formula` | yes | who supplies the number: the buyer states it, a benchmark carries it, the record holds it, or the formula computes it |
| `question` | `text` | no | for a driver the buyer states: the question in the buyer's own words |
| `bounds` | [Interval](/concepts/interval) | no | the floor and the ceiling a stated value may not cross |



## Routes that use it
No route takes or returns DriverNode directly. The record holds it, and the objects that point at it reach it.