Express

Lightrun for Express¶

To use Lightrun with a Express application:

In your project's folder, install the node agent by running npm install lightrun.
Import Lightrun at the start of your application file (for example, app.js) by adding the following code:
```
require('lightrun').start({
     lightrunSecret: '<LIGHTRUN_SECRET>'
});
```
Run the application as you normally would; for example, node index.js or npm start.

Getting Company Details

To get your <LIGHTRUN_SECRET> key, log into the Management Portal and inspect the Set Up An Agent section, under Getting Started.

Running the agent in TypeScript applications¶

Important

As part of Lightrun’s commitment to align with industry standards, we strongly advise using the TypeScript Compiler (tsc) and not ts-node in production environments. This choice not only ensures a more efficient memory footprint but also avoids generating unnecessary type information.

It's essential to note that when utilizing Lightrun for TypeScript in a production setting, you must include sourcemap files on the server where your production software is deployed. This step is crucial for seamless debugging and troubleshooting.

Instructions

Insert the following code at the start of your application file (for example, index.ts or app.ts).
```
import * as lightrun from 'lightrun';

lightrun.start({
    lightrunSecret: '<LIGHTRUN_SECRET>',
    filename: <full_path_to_metadata_file>
});
```
Info

The filename parameter is optional. See here for details on constructing the metadata file.
In the compilerOptions section of the tsconfig.json file, set the parameter "sourceMap" to "true".
From a terminal, run the application.
```
node index.js
```

Last update: July 1, 2025