README

Browser Log Collection

Send logs to Datadog from web browsers or other Javascript clients with the browser logs SDK.

With the browser logs SDK, you can send logs directly to Datadog from JS clients and leverage the following features:

Use the SDK as a logger. Everything is forwarded to Datadog as JSON documents.
Add context and extra custom attributes to each log sent.
Wrap and forward every frontend error automatically.
Forward frontend errors.
Record real client IP addresses and user agents.
Optimized network usage with automatic bulk posts.

Setup

Datadog client token: For security reasons, API keys cannot be used to configure the browser logs SDK, because they would be exposed client-side in the JavaScript code. To collect logs from web browsers, a client token must be used. See the client token documentation for more details.

Datadog browser logs SDK: Configure the SDK through NPM or use the CDN async or CDN sync code snippets in the head tag.

Supported browsers: The browser logs SDK supports all modern desktop and mobile browsers including IE11. See the browser support table.

Choose the right installation method

Installation method	Use case
npm (node package manager)	This method is recommended for modern web applications. The browser logs SDK gets packaged with the rest of your front-end javascript code. It has no impact on page load performance. However, the SDK might miss errors, resources and user actions triggered before the SDK is initialized. Note: it is recommended to use a matching version with RUM SDK if used.
CDN async	This method is recommended for web applications with performance targets. The browser logs SDK is loaded from our CDN asynchronously: this method ensures the SDK download does not impact page load performance. However, the SDK might miss errors, resources and user actions triggered before the SDK is initialized.
CDN sync	This method is recommended for collecting all RUM events. The browser logs SDK is loaded from our CDN synchronously: this method ensures the SDK is loaded first and collects all errors, resources and user actions. This method might impact page load performance.

NPM

After adding @datadog/browser-logs to your package.json file, initialize it with:

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.init({
  clientToken: '<DATADOG_CLIENT_TOKEN>',
  site: '<DATADOG_SITE>',
  forwardErrorsToLogs: true,
  sampleRate: 100,
})

CDN async

Load and configure the SDK in the head section of your pages.

<html>
  <head>
    <title>Example to send logs to Datadog</title>
      <script>
      (function(h,o,u,n,d) {
        h=h[d]=h[d]||{q:[],onReady:function(c){h.q.push(c)}}
        d=o.createElement(u);d.async=1;d.src=n
        n=o.getElementsByTagName(u)[0];n.parentNode.insertBefore(d,n)
      })(window,document,'script','https://www.datadoghq-browser-agent.com/datadog-logs-v4.js','DD_LOGS')
      DD_LOGS.onReady(function() {
          DD_LOGS.init({
            clientToken: 'XXX',
            site: 'datadoghq.com',
            forwardErrorsToLogs: true,
            sampleRate: 100,
          })
        })
      </script>
  </head>
</html>

Note: Early API calls must be wrapped in the DD_LOGS.onReady() callback. This ensures the code only gets executed once the SDK is properly loaded.

CDN sync

To receive all logs and errors, load and configure the SDK at the beginning of the head section for your pages.

<html>
  <head>
    <title>Example to send logs to Datadog</title>
    <script type="text/javascript" src="https://www.datadoghq-browser-agent.com/datadog-logs-v4.js"></script>
    <script>
      window.DD_LOGS &&
        DD_LOGS.init({
          clientToken: '<CLIENT_TOKEN>',
          site: '<DATADOG_SITE>',
          forwardErrorsToLogs: true,
          sampleRate: 100,
        })
    </script>
  </head>
</html>

Note: The window.DD_LOGS check is used to prevent issues if a loading failure occurs with the SDK.

TypeScript

Types are compatible with TypeScript >= 3.8.2. For earlier versions, import JS sources and use global variables to avoid any compilation issues:

import '@datadog/browser-logs/bundle/datadog-logs'

window.DD_LOGS.init({
  clientToken: '<CLIENT_TOKEN>',
  site: '<DATADOG_SITE>',
  forwardErrorsToLogs: true,
  sampleRate: 100,
})

Configuration

Initialization parameters

The following parameters are available to configure the Datadog browser logs SDK to send logs to Datadog:

Parameter	Type	Required	Default	Description
`clientToken`	String	Yes		A Datadog client token.
`site`	String	Yes	`datadoghq.com`	The Datadog site of your organization. US: `datadoghq.com`, EU: `datadoghq.eu`
`service`	String	No		The service name for your application.
`env`	String	No		The application’s environment, for example: prod, pre-prod, staging, etc.
`version`	String	No		The application’s version, for example: 1.2.3, 6c44da20, 2020.02.13, etc.
`forwardErrorsToLogs`	Boolean	No	`true`	Set to `false` to stop forwarding console.error logs, uncaught exceptions and network errors to Datadog.
`sampleRate`	Number	No	`100`	The percentage of sessions to track: `100` for all, `0` for none. Only tracked sessions send logs.
`silentMultipleInit`	Boolean	No		Prevent logging errors while having multiple init.
`proxyUrl`	Boolean	No		Optional proxy URL (ex: https://www.proxy.com/path), see the full proxy setup guide for more information.

Options that must have a matching configuration when using the RUM SDK:

Parameter	Type	Required	Default	Description
`trackSessionAcrossSubdomains`	Boolean	No	`false`	Preserve the session across subdomains for the same site.
`useSecureSessionCookie`	Boolean	No	`false`	Use a secure session cookie. This disables logs sent on insecure (non-HTTPS) connections.
`useCrossSiteSessionCookie`	Boolean	No	`false`	Use a secure cross-site session cookie. This allows the logs SDK to run when the site is loaded from another one (iframe). Implies `useSecureSessionCookie`.

Usage

Custom logs

After the Datadog browser logs SDK is initialized, send a custom log entry directly to Datadog with the API:

logger.debug | info | warn | error (message: string, messageContext = Context)

NPM

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.logger.info('Button clicked', { name: 'buttonName', id: 123 })

CDN async

DD_LOGS.onReady(function () {
  DD_LOGS.logger.info('Button clicked', { name: 'buttonName', id: 123 })
})

Note: Early API calls must be wrapped in the DD_LOGS.onReady() callback. This ensures the code only gets executed once the SDK is properly loaded.

CDN sync

window.DD_LOGS && DD_LOGS.logger.info('Button clicked', { name: 'buttonName', id: 123 })

Note: The window.DD_LOGS check is used to prevent issues if a loading failure occurs with the SDK.

Results

The results are the same when using NPM, CDN async or CDN sync:

{
  "status": "info",
  "session_id": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "name": "buttonName",
  "id": 123,
  "message": "Button clicked",
  "date": 1234567890000,
  "http": {
    "useragent": "Mozilla/5.0 ...",
  },
  "view": {
    "url": "https://...",
    "referrer": "https://...",
  },
  "network": {
    "client": {
      "geoip": {...}
      "ip": "xxx.xxx.xxx.xxx"
    }
  }
}

The Logs SDK adds the following information by default (more fields can be added if the RUM SDK is present):

date
view.url
view.referrer
session_id (only if a session is used)

The Datadog backend adds more fields, like:

http.useragent
network.client.ip

Status parameter

After the Datadog browser logs SDK is initialized, send a custom log entry to Datadog with the API using the status as a parameter:

log (message: string, messageContext: Context, status? = 'debug' | 'info' | 'warn' | 'error')

NPM

For NPM, use:

import { datadogLogs } from '@datadog/browser-logs';

datadogLogs.logger.log(<MESSAGE>,<JSON_ATTRIBUTES>,<STATUS>);

CDN async

For CDN async, use:

DD_LOGS.onReady(function() {
  DD_LOGS.logger.log(<MESSAGE>,<JSON_ATTRIBUTES>,<STATUS>);
})

Note: Early API calls must be wrapped in the DD_LOGS.onReady() callback. This ensures the code only gets executed once the SDK is properly loaded.

CDN sync

For CDN sync, use:

window.DD_LOGS && DD_LOGS.logger.log(<MESSAGE>,<JSON_ATTRIBUTES>,<STATUS>);

Placeholders

The placeholders in the examples above are described below:

Placeholder	Description
`<MESSAGE>`	The message of your log that is fully indexed by Datadog.
`<JSON_ATTRIBUTES>`	A valid JSON object, which includes all attributes attached to the `<MESSAGE>`.
`<STATUS>`	The status of your log; accepted status values are `debug`, `info`, `warn`, or `error`.

Advanced usage

Scrub sensitive data from your Browser logs

If your Browser logs contain sensitive information that needs redacting, configure the Browser SDK to scrub sensitive sequences by using the beforeSend callback when you initialize the Browser Log Collector.

The beforeSend callback function gives you access to each log collected by the Browser SDK before it is sent to Datadog, and lets you update any property.

To redact email addresses from your web application URLs:

NPM

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.init({
    ...,
    beforeSend: (log) => {
        // remove email from view url
        log.view.url = log.view.url.replace(/email=[^&]*/, "email=REDACTED")
    },
    ...
});

CDN Async

DD_LOGS.onReady(function() {
    DD_LOGS.init({
        ...,
        beforeSend: (log) => {
            // remove email from view url
            log.view.url = log.view.url.replace(/email=[^&]*/, "email=REDACTED")
        },
        ...
    })
})

CDN Sync

window.DD_LOGS &&
    window.DD_LOGS.init({
        ...,
        beforeSend: (log) => {
            // remove email from view url
            log.view.url = log.view.url.replace(/email=[^&]*/, "email=REDACTED")
        },
        ...
    });

The following properties are automatically collected by the SDK and could contain sensitive data:

Attribute	Type	Description
`view.url`	String	The URL of the active web page.
`view.referrer`	String	The URL of the previous web page from which a link to the currently requested page was followed.
`message`	String	The content of the log.
`error.stack`	String	The stack trace or complementary information about the error.
`http.url`	String	The HTTP URL.

Discard specific logs

The beforeSend callback function allows you to also discard a log before it is sent to Datadog.

To discard network errors if their status is 404:

NPM

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.init({
    ...,
    beforeSend: (log) => {
        // discard 404 network errors
        if (log.http && log.http.status_code === 404) {
          return false
        }
    },
    ...
});

CDN Async

DD_LOGS.onReady(function() {
    DD_LOGS.init({
        ...,
        beforeSend: (log) => {
          // discard 404 network errors
          if (log.http && log.http.status_code === 404) {
            return false
          }
        },
        ...
    })
})

CDN Sync

window.DD_LOGS &&
    window.DD_LOGS.init({
        ...,
        beforeSend: (log) => {
          // discard 404 network errors
          if (log.http && log.http.status_code === 404) {
            return false
          }
        },
        ...
    });

Define multiple loggers

The Datadog browser logs SDK contains a default logger, but it is possible to define different loggers.

Create a new logger

After the Datadog browser logs SDK is initialized, use the API createLogger to define a new logger:

createLogger (name: string, conf?: {
    level?: 'debug' | 'info' | 'warn' | 'error',
    handler?: 'http' | 'console' | 'silent',
    context?: Context
})

Note: These parameters can be set with the setLevel, setHandler, and setContext APIs.

Get a custom logger

After the creation of a logger, access it in any part of your JavaScript code with the API:

getLogger(name: string)

NPM

For example, assume there is a signupLogger, defined with all the other loggers:

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.createLogger('signupLogger', 'info', 'http', { env: 'staging' })

It can now be used in a different part of the code with:

import { datadogLogs } from '@datadog/browser-logs'

const signupLogger = datadogLogs.getLogger('signupLogger')
signupLogger.info('Test sign up completed')

CDN async

For example, assume there is a signupLogger, defined with all the other loggers:

DD_LOGS.onReady(function () {
  const signupLogger = DD_LOGS.createLogger('signupLogger', 'info', 'http', { env: 'staging' })
})

It can now be used in a different part of the code with:

DD_LOGS.onReady(function () {
  const signupLogger = DD_LOGS.getLogger('signupLogger')
  signupLogger.info('Test sign up completed')
})

Note: Early API calls must be wrapped in the DD_LOGS.onReady() callback. This ensures the code only gets executed once the SDK is properly loaded.

CDN sync

For example, assume there is a signupLogger, defined with all the other loggers:

if (window.DD_LOGS) {
  const signupLogger = DD_LOGS.createLogger('signupLogger', 'info', 'http', { env: 'staging' })
}

It can now be used in a different part of the code with:

if (window.DD_LOGS) {
  const signupLogger = DD_LOGS.getLogger('signupLogger')
  signupLogger.info('Test sign up completed')
}

Note: The window.DD_LOGS check is used to prevent issues if a loading failure occurs with the SDK.

Overwrite context

Global context

After the Datadog browser logs SDK is initialized, it is possible to:

Set the entire context for all your loggers with the setLoggerGlobalContext (context: Context) API.
Add a context to all your loggers with addLoggerGlobalContext (key: string, value: any) API.
Get the entire global context with getLoggerGlobalContext () API.

NPM

For NPM, use:

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.setLoggerGlobalContext({ env: 'staging' })

datadogLogs.addLoggerGlobalContext('referrer', document.referrer)

const context = datadogLogs.getLoggerGlobalContext() // => {env: 'staging', referrer: ...}

CDN async

For CDN async, use:

DD_LOGS.onReady(function () {
  DD_LOGS.setLoggerGlobalContext({ env: 'staging' })
})

DD_LOGS.onReady(function () {
  DD_LOGS.addLoggerGlobalContext('referrer', document.referrer)
})

DD_LOGS.onReady(function () {
  var context = DD_LOGS.getLoggerGlobalContext() // => {env: 'staging', referrer: ...}
})

Note: Early API calls must be wrapped in the DD_LOGS.onReady() callback. This ensures the code only gets executed once the SDK is properly loaded.

CDN sync

For CDN sync, use:

window.DD_LOGS && DD_LOGS.setLoggerGlobalContext({ env: 'staging' })

window.DD_LOGS && DD_LOGS.addLoggerGlobalContext('referrer', document.referrer)

var context = window.DD_LOGS && DD_LOGS.getLoggerGlobalContext() // => {env: 'staging', referrer: ...}

Note: The window.DD_LOGS check is used to prevent issues if a loading failure occurs with the SDK.

Logger context

After a logger is created, it is possible to:

Set the entire context for your logger with the setContext (context: Context) API.
Add a context to your logger with addContext (key: string, value: any) API:

NPM

For NPM, use:

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.setContext("{'env': 'staging'}")

datadogLogs.addContext('referrer', document.referrer)

CDN async

For CDN async, use:

DD_LOGS.onReady(function () {
  DD_LOGS.setContext("{'env': 'staging'}")
})

DD_LOGS.onReady(function () {
  DD_LOGS.addContext('referrer', document.referrer)
})

Note: Early API calls must be wrapped in the DD_LOGS.onReady() callback. This ensures the code only gets executed once the SDK is properly loaded.

CDN sync

For CDN sync, use:

window.DD_LOGS && DD_LOGS.setContext("{'env': 'staging'}")

window.DD_LOGS && DD_LOGS.addContext('referrer', document.referrer)

Note: The window.DD_LOGS check is used to prevent issues if a loading failure occurs with the SDK.

Filter by status

After the Datadog browser logs SDK is initialized, the minimal log level for your logger is set with the API:

setLevel (level?: 'debug' | 'info' | 'warn' | 'error')

Only logs with a status equal to or higher than the specified level are sent.

NPM

For NPM, use:

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.logger.setLevel('<LEVEL>')

CDN async

For CDN async, use:

DD_LOGS.onReady(function () {
  DD_LOGS.logger.setLevel('<LEVEL>')
})

Note: Early API calls must be wrapped in the DD_LOGS.onReady() callback. This ensures the code only gets executed once the SDK is properly loaded.

CDN sync

For CDN sync, use:

window.DD_LOGS && DD_LOGS.logger.setLevel('<LEVEL>')

Note: The window.DD_LOGS check is used to prevent issues if a loading failure occurs with the SDK.

Change the destination

By default, loggers created by the Datadog browser logs SDK are sending logs to Datadog. After the Datadog browser logs SDK is initialized, it is possible to configure the logger to:

send logs to the console and Datadog (http)
send logs to the console only
not send logs at all (silent)

setHandler (handler?: 'http' | 'console' | 'silent' | Array<handler>)

NPM

For NPM, use:

import { datadogLogs } from '@datadog/browser-logs'

datadogLogs.logger.setHandler('<HANDLER>')
datadogLogs.logger.setHandler(['<HANDLER1>', '<HANDLER2>'])

CDN async

For CDN async, use:

DD_LOGS.onReady(function () {
  DD_LOGS.logger.setHandler('<HANDLER>')
  DD_LOGS.logger.setHandler(['<HANDLER1>', '<HANDLER2>'])
})

Note: Early API calls must be wrapped in the DD_LOGS.onReady() callback. This ensures the code only gets executed once the SDK is properly loaded.

CDN sync

For CDN sync, use:

window.DD_LOGS && DD_LOGS.logger.setHandler('<HANDLER>')
window.DD_LOGS && DD_LOGS.logger.setHandler(['<HANDLER1>', '<HANDLER2>'])

Note: The window.DD_LOGS check is used to prevent issues if a loading failure occurs with the SDK.

Usage no npm install needed!

README

Browser Log Collection

Setup

Choose the right installation method

NPM

CDN async

CDN sync

TypeScript

Configuration

Initialization parameters

Usage

Custom logs

NPM

CDN async

CDN sync

Results

Status parameter

NPM

CDN async

CDN sync

Placeholders

Advanced usage

Scrub sensitive data from your Browser logs

NPM

CDN Async

CDN Sync

Discard specific logs

NPM

CDN Async

CDN Sync

Define multiple loggers

Create a new logger

Get a custom logger

NPM

CDN async

CDN sync

Overwrite context

Global context

NPM

CDN async

CDN sync

Logger context

NPM

CDN async

CDN sync

Filter by status

NPM

CDN async

CDN sync

Change the destination

NPM

CDN async

CDN sync