# Analytics for Node.js Migration Guide

If you're using the [classic version of Analytics Node.js](/docs/segment/connections/sources/catalog/libraries/server/node/classic) (named `analytics-node` on npm), [upgrade to the latest version of Analytics Node.js](/docs/segment/connections/sources/catalog/libraries/server/node/) (named `@segment/analytics-node` on npm).

1. Change the named imports.

   <br /> Before:

   ```javascript
   import Analytics from 'analytics-node'
   ```

   After:

   ```javascript
   import { Analytics } from '@segment/analytics-node'
   ```
2. Change instantiation to have an object as the first argument.

   <br /> Before:

   ```javascript
   var analytics = new Analytics('YOUR_WRITE_KEY');
   ```

   After:

   ```javascript
   const analytics = new Analytics({ writeKey: '<YOUR_WRITE_KEY>' })
   ```
3. Change flushing to [graceful shutdown](/docs/segment/connections/sources/catalog/libraries/server/node/#graceful-shutdown).

   <br /> Before:

   ```javascript
   await analytics.flush((err, batch) => {
       console.log('Flushed, and now this program can exit!');
   });
   ```

   After:

   ```javascript
   await analytics.flush({ close: true })
   ```

## Key differences between the classic and updated version

* The callback call signature changed.

  <br />Before:

  ```javascript
  (err, batch) => void
  ```

  After:

  ```javascript
  (err, ctx) => void
  ```
* The `enable` setting (for disabling analytics during tests) changed to `disable`. `enable: false` changed to `disable: true`.

### Removals

The updated Analytics Node.js removed these configuration options:

* `errorHandler` (see the docs on [error handling](/docs/segment/connections/sources/catalog/libraries/server/node/#error-handling) for more information)

The updated Analytics Node.js library removed undocumented behavior around `track` properties

Before:

```javascript
analytics.track({
 ...
 event: 'Ultimate Played',
 myProp: 'abc'
})
```

After:

```javascript
analytics.track({
 ...
 event: 'Ultimate Played',
 properties:  {
   myProp: 'abc'
 }
})
```