﻿---
title: Configuring the agent
description: There are multiple ways to configure the Node.js agent. In order of precedence: APM Agent Central Configuration via Kibana. (supported options are marked...
url: https://www.elastic.co/elastic/docs-builder/docs/2841/reference/apm/agents/nodejs/configuring-agent
products:
  - APM Agent
  - APM Node.js Agent
applies_to:
  - Serverless Observability projects: Generally available
  - Elastic Stack: Generally available
  - Application Performance Monitoring Agent for Node.js: Generally available
---

# Configuring the agent
There are multiple ways to configure the Node.js agent. In order of precedence:
1. APM Agent Central Configuration via Kibana. (supported options are marked with [![dynamic config](https://www.elastic.co/elastic/docs-builder/docs/2841/reference/apm/agents/nodejs/images/dynamic-config.svg) ](#dynamic-configuration))
2. Environment variables.
3. If calling the `apm.start()` function, supply a [configurations object](#agent-configuration-object) as the first argument.
4. Via the [agent configuration file](#agent-configuration-file).

For information on the available configuration properties and the expected names of environment variables, see the [Configuration options](https://www.elastic.co/elastic/docs-builder/docs/2841/reference/apm/agents/nodejs/configuration) documentation.

## Dynamic configuration

Configuration options marked with the ![dynamic config](https://www.elastic.co/elastic/docs-builder/docs/2841/reference/apm/agents/nodejs/images/dynamic-config.svg) badge can be changed at runtime when set from a supported source.
The Node.js Agent supports [Central configuration](https://docs-v3-preview.elastic.dev/elastic/docs-builder/docs/2841/solutions/observability/apm/apm-agents/central-configuration), which allows you to fine-tune certain configurations via the APM app in Kibana. This feature is enabled in the Agent by default, with [`centralConfig`](/elastic/docs-builder/docs/2841/reference/apm/agents/nodejs/configuration#central-config).

## Agent configuration object

To use the optional `options` argument, pass it into the `apm.start()` method:
```js
var apm = require('elastic-apm-node').start({
  // add configuration options here
})
```

This example shows how to configure the agent to only be active in production:
```js
// Add this to the VERY top of the first file loaded in your app
require('elastic-apm-node').start({
  // Override service name from package.json
  // Allowed characters: a-z, A-Z, 0-9, -, _, and space
  serviceName: '',

  // Use if APM Server requires a token
  secretToken: '',

  // Use if APM Server uses API keys for authentication
  apiKey: '',

  // Set custom APM Server URL (default: http://127.0.0.1:8200)
  serverUrl: '',

  // Only activate the agent if it's running in production
  active: process.env.NODE_ENV === 'production'
})
```


## Agent configuration file

The Node.js agent looks for a file named `elastic-apm-node.js` in the current working directory. You can specify a custom path for this file with the [`configFile`](/elastic/docs-builder/docs/2841/reference/apm/agents/nodejs/configuration#config-file) configuration option.