---
title: "RateBound"
description: "rate, politeness and cost as typed values with dimensions"
section: concepts
address: /concepts/ratebound
contract: 0476e35e6e275db5
---

# RateBound

rate, politeness and cost as typed values with dimensions

[figure: RateBound 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 | registers |



## Fields


| field | type | required | note |
|---|---|---|---|
| `calls` | `count` | yes |  |
| `per` | `duration` | yes |  |
| `politeness_budget` | `count` | yes | the calls that the host may make on the way within each period of the rate (per), at most the rate's calls, so that the host decides when to read within it and never reads at the source's ceiling; 0 sets no bound beyond the rate itself. It is a parameter of the source family, counted in calls per unit of time and enforced at the call under the lease (07 §2.1; 18 §2.1 and its parameters table) |
| `cost_per_call` | `money` | no |  |
| `ceiling_measured` | `count` | no | the measured ceiling of the rate |



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