---
title: "ModelStock"
description: "one stock of a systems model: the units of one kind in one place, read from a chain stock where the chain holds one"
section: concepts
address: /concepts/modelstock
contract: 0476e35e6e275db5
---

# ModelStock

one stock of a systems model: the units of one kind in one place, read from a chain stock where the chain holds one

[figure: ModelStock 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 | none |
| store | none |
| family | market |



## Fields


| field | type | required | note |
|---|---|---|---|
| `name` | `text` | yes |  |
| `unit` | `text` | yes |  |
| `chain_stock` | `text` | no | the chain stock whose count starts it, by name |
| `initial` | [DriverNode](/concepts/drivernode) | no | how its starting level is read when no chain stock holds it |
| `reader` | `text` | yes | who reads it; a stock with no reader is a leak |
| `waiting` | `duration` | no | how long a unit may wait on it |



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