We tried to make it as simple as possible to report the data you need to analyze your app usage and improve it.

This module is compatible with Python 3+.

To start using this module, sign up and get an app ID on


$ pip install nucleus-python

Basic usage

Add the following code to import Nucleus and init the analytics.

Don't use the import ... from syntax as you won't be able to set the module options like app_id.

import nucleus

nucleus.app_id = 'your app id'

	'version': '0.5.0', # Set app version (Nucleus cannot detect it)
	'userId': 'richard_hendrix'


Only use app_started() once per session, if you are using Nucleus in several files call app_started() the earliest possible.

Sign up and get a tracking ID for your app here.


You can init Nucleus with options:

nucleus.report_interval = 20 # interval (in seconds) between server com
nucleus.disable_tracking = False # completely disable tracking
nucleus.debug = False # Show internal logs to help debug
nucleus.auto_user_id = False # Assign the user an ID

Identify users

You can track specific users actions on the 'User Explorer' section of your dashboard by assigning an user ID.

It can be any value as long as it is a string.


Alternatively, set the auto_user_id option of the module to True to automatically assign the user an ID based on his username and hostname.

Modify automatic data

You can overwrite some properties or fill data that wasn't detected.

You have to do it before calling app_started() for this to work

It is a good idea to set your app version directly as Nucleus cannot detect it for the moment.

	'version': '0.5.0',
	'locale': 'en_US'

Track custom data

You can also add custom data along with the automatic data.

Those will be visible in your user dashboard if you previously set an user ID.

The module will remember past properties so you can use nucleus.set_props multiple times without overwriting past props.

Properties can either numbers, strings or booleans. Nested properties or arrays aren't supported at the moment.

	"age": 34,
	"name": 'Richard Hendricks',
	"job": 'CEO'

To overwrite past properties, set the second parameter to True.

	"age": 23
}, True)


To catch errors with Nucleus, simply add the tracking code to an exception and pass the exception as the unique parameter.

Nucleus will extract the relevant informations and show them in your dashboard.

except Exception as e:

Add this at the outermost level of your code to handle any otherwise uncaught exceptions before terminating.

The advantage of except Exception over the bare except is that there are a few exceptions that it wont catch, most obviously KeyboardInterrupt and SystemExit.


After initializing Nucleus, you can send your own custom events.


They are a couple event names that are reserved by Nucleus: init, error: and nucleus:.

You shouldn't report events containing these strings.

Tracking with data

You can add extra information to tracked events, as an object.

Properties can either numbers, strings or booleans.

Nested properties or arrays aren't supported at the moment.


nucleus.track("PLAYED_TRACK", data = {
	"trackName": 'My Awesome Song',
	"duration": 120

Toggle tracking

This will completely disable any communication with Nucleus' servers.

To opt-out your users from tracking:


and to opt back in:


This doesn't persist after restarts so you have to handle saving the setting.

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