---
lang: en
title: 'API docs: boot.bootstrapper._constructor_'
keywords: LoopBack 4.0, LoopBack 4, Node.js, TypeScript, OpenAPI
sidebar: lb4_sidebar
editurl: https://github.com/strongloop/loopback-next/tree/master/packages/boot
permalink: /doc/en/lb4/apidocs.boot.bootstrapper._constructor_.html
---

<!-- Do not edit this file. It is automatically generated by API Documenter. -->

[Home](./index.md) &gt; [@loopback/boot](./boot.md) &gt; [Bootstrapper](./boot.bootstrapper.md) &gt; [(constructor)](./boot.bootstrapper._constructor_.md)

## Bootstrapper.(constructor)

Constructs a new instance of the `Bootstrapper` class

<b>Signature:</b>

```typescript
constructor(app: Application & Bootable, projectRoot: string, bootOptions?: BootOptions);
```

## Parameters

|  Parameter | Type | Description |
|  --- | --- | --- |
|  app | [Application](./core.application.md) &amp; [Bootable](./boot.bootable.md) |  |
|  projectRoot | string |  |
|  bootOptions | [BootOptions](./boot.bootoptions.md) |  |