Configuring the JavaScript library · Docs

The web library works without any configuration beyond the snippet. When you need to change what it collects, add options to the myjourney.init call inside the snippet.

myjourney.init("<your project token>", {
  api_host: "https://app.myjourneyanalytics.com",
  defaults: "2026-05-30",
  person_profiles: "identified_only",
  // your extra options go here
});

Keep the token, api_host and defaults exactly as the snippet in Settings → Project → General shows them. To change an option after start-up, call myjourney.set_config({ ... }).

Some behaviour is also controlled from the app, in Settings → Project. Where both exist, the sections below say which one wins.

The defaults date

The defaults option fixes the library's default behaviour to a dated set, so a library update never changes what you collect without you choosing it. With the date in the current snippet, the library:

records a pageview on page load and each time the page's path changes in a single-page app;
marks visits from localhost and 127.0.0.1 as an internal test user.

Pageviews and page leaves

Option	Default	What it does
`capture_pageview`	`'history_change'`	`true` records only the first pageview of each page load; `false` records none, so you send `$pageview` yourself.
`capture_pageleave`	`'if_capture_pageview'`	Records `$pageleave` when pageviews are being recorded. `true` or `false` to choose yourself.

Autocapture

Autocapture records clicks, changes and form submissions as $autocapture events. See Autocapture for what it records and how to exclude elements.

Option	What it does
`autocapture: false`	Turns autocapture off in this browser.
`autocapture: { url_allowlist: [...] }`	Captures only on pages whose address matches one of the strings or regular expressions.
`autocapture: { url_ignorelist: [...] }`	Never captures on matching pages.
`autocapture: { dom_event_allowlist: ["click"] }`	Limits autocapture to some of `click`, `change` and `submit`.
`autocapture: { css_selector_allowlist: [...] }`	Captures only elements that match one of the CSS selectors.
`autocapture: { element_attribute_ignorelist: [...] }`	Leaves the named attributes out of autocapture events.
`mask_all_text`	Leaves element text out of autocapture events.
`mask_all_element_attributes`	Leaves element attributes out of autocapture events.
`rageclick`	Records `$rageclick` when someone clicks the same place repeatedly. On by default; `false` turns it off.
`capture_dead_clicks`	`true` records clicks that change nothing on the page.

Turning off Enable autocapture for web in Settings → Project → Autocapture stops autocapture for the whole project, whatever the code says.

Session replay

Recording starts only when Record user sessions is on in Settings → Project → Session replay. In code:

Option	What it does
`disable_session_recording: true`	Never records in this browser. Use `myjourney.startSessionRecording()` to start recording yourself.
`session_recording: { maskAllInputs: true }`	Masks everything typed into fields.
`session_recording: { maskTextSelector: "*" }`	Masks the text of matching elements; `"*"` masks all text.
`session_recording: { blockSelector: ".payment-form" }`	Leaves matching elements out of recordings.

Masking options set in code take priority over Privacy and masking in the app. See Session replay.

Other features

Option	What it does
`capture_heatmaps`	`true` or `false` to record heatmap data from this browser, overriding the project setting.
`capture_exceptions`	`true` records uncaught errors and unhandled promise rejections as `$exception` events; `false` stops it. Left out, the project's Exception autocapture setting decides.
`disable_surveys: true`	Never loads or shows surveys in this browser.

Storage and cookies

The library keeps the visitor's ID, session and super properties in the browser.

Option	Default	What it does
`persistence`	`'localStorage+cookie'`	Where to store them: `'localStorage+cookie'`, `'localStorage'`, `'cookie'`, `'sessionStorage'` or `'memory'` (nothing kept between page loads).
`cross_subdomain_cookie`	`true`	Shares the cookie across your subdomains, such as `www.example.com` and `shop.example.com`. It is off automatically on `herokuapp.com`, `vercel.app` and `netlify.app` subdomains.
`cookie_expiration`	`365`	How many days the cookie lasts.
`secure_cookie`	`true` on HTTPS pages	Sets the cookie's `Secure` flag.

What the library stores, for your cookie policy:

Name	Holds
`mj_<project token>_mja`	The visitor's ID, session and super properties.
`__mj_opt_in_out_<project token>`	The visitor's opt-in or opt-out choice.

Option	What it does
`opt_out_capturing_by_default: true`	Captures nothing until you call `myjourney.opt_in_capturing()`.
`respect_dnt: true`	Captures nothing in browsers that send Do Not Track or Global Privacy Control.
`property_denylist: ["$referrer"]`	Removes the named properties from every event before it is sent.
`mask_personal_data_properties: true`	Masks advertising click IDs such as `gclid` and `fbclid` in captured addresses. Add your own query parameter names with `custom_personal_data_properties`.

To stop storing visitors' IP addresses for the whole project, turn on Discard client IP data in Settings → Project → Privacy.

Edit or drop events before they are sent

before_send runs on every event just before it leaves the browser. Return the event, changed or not, to send it, or null to drop it.

myjourney.init("<your project token>", {
  // ...the snippet's options...
  before_send: (event) => {
    if (event && event.properties.$current_url?.includes("/admin")) {
      return null; // never send events from admin pages
    }
    return event;
  },
});

You can pass an array of functions; they run in order, and any one returning null drops the event.

Sessions

session_idle_timeout_seconds sets how long a visitor can be idle before their next event starts a new session. The default is 1800 (30 minutes); values from 60 seconds to 10 hours are accepted. See Sessions.

Start with a known ID

bootstrap starts the library with an ID you already have, for example one your server set for the visitor:

bootstrap: { distinctID: "visitor_abc" },

Add isIdentifiedID: true when the ID is a signed-in user's ID rather than an anonymous one. Use an existing visitor ID shows how to do this only on a visitor's first page load.

Run code once the library has loaded

loaded: (myjourney) => {
  // the library is ready, for example:
  // myjourney.register({ app_version: "3.2.0" });
},

Can't find what you need? Contact support