# Source Map Support
Source: https://pm2.keymetrics.io/docs/usage/source-map-support/

If you use [BabelJS](https://babeljs.io/), [Typescript](http://www.typescriptlang.org/) or any other Javascript superset you may have noticed that when an exception occurs, the stacktrace is not meaningful at all. To get useful information you need to generate [source map files](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/).

Once these source map files are generated, PM2 will automatically detect them and will help you inspect errors.

## Source map

Since version 1.0.2, PM2 embeds a mechanism to support javascript source maps.

**PM2 automatically detects javascript source map files** if you start app.js, it will expect app.js.map to exist as well.

If you have a different layout, you can force source map support by starting your application:

Via CLI:

```bash
pm2 start app.js --source-map-support
```

Or via JSON file:

```javascript
module.exports = {
   name: 'babel-app',
   script: 'app.js',
   source_map_support: true
}
```

### Inspect exceptions

Exceptions are logged into your application error log file.

To check your logs to detect exceptions, you can type:

```bash
pm2 logs main
```

Otherwise, use [PM2.io](https://pm2.io/) to have a clean listing and notifications of new alerts.

### Disable source map support

If you do not want PM2 to automatically support javascript source maps you can use the option `--disable-source-map-support`.

This is supported both via CLI and via a JSON file.