# Setup

### 1. Find an extension.

For this guide, we will use a custom function. You can find one on your own, or use our [Extension Finder](https://coolstone.dev/dubnium/extensions/).

{% code title="createHelloWorld.js" lineNumbers="true" %}

```javascript
(db) => {
if(!db) throw new Error("This extension requires database permissions")
db.create('hello', `Hello, World!`)
}
```

{% endcode %}

### 2. Define permissons

{% code lineNumbers="true" %}

```javascript
const { extensionPermissions } = require('dubnium')
const permissions = new extensionPermissions(true, false, [ 'edit' ]) 
```

{% endcode %}

<table><thead><tr><th>Parameter</th><th>About</th><th data-type="checkbox">Required</th></tr></thead><tbody><tr><td>record</td><td>Allow access to the Record when extending the record editor API</td><td>true</td></tr><tr><td>database</td><td>Allow access to the entire database when extending the database.</td><td>true</td></tr><tr><td>filterList</td><td>An array of function names to omit from an extension.</td><td>false</td></tr></tbody></table>

### 3. Add to Dubnium

{% code lineNumbers="true" %}

```javascript
db.extend('name', require('./extension'), permissions)
```

{% endcode %}

{% code lineNumbers="true" %}

```javascript
db.get('tag').extend('name', require('./extension'), permissions)
```

{% endcode %}

### 4. Use the extension

{% code lineNumbers="true" %}

```javascript
db.name()
```

{% endcode %}

### Full Example

{% code title="createHelloWorld.js" lineNumbers="true" %}

```javascript
db.extend('createHelloWorld', (db) => {
if(!db) throw new Error("This extension requires database permissions")
db.create('hello', `Hello, World!`)
}, new extensionPermissions(false, true))

db.createHelloWorld()
```

{% endcode %}