Anonymous tracking for the React Native tracker

Anonymous tracking is a feature that enables anonymization of various user and session identifiers, to support user privacy when consent for tracking the identifiers isn't given.

On React Native, the following user and session identifiers can be anonymized:

• Client-side user identifiers:
  • user_id, domain_userid, network_userid, and user_ipaddress, set by you in Subject
  • userId, a device ID, set automatically in the session entity
  • For mobile only, IDFA identifiers (appleIdfa and appleIdfv for iOS, androidIdfa for Android) in the mobile entity if configured
• Client-side session identifiers:
  • previousSessionId in the session entity, set automatically by the tracker
• Server-side user identifiers:
  • network_userid and user_ipaddress, set by the Collector

User-set properties

The Collector captures the IP address from the request HTTP headers, and updates the user_ipaddress event property. However, if you set the user_ipaddress property in the Subject, that value has priority.

Similarly, if you set the network_userid property in the Subject, that value is used instead of the Collector cookie value.

Read more about anonymous tracking in the overview page.

There are several levels to the anonymization depending on which of the categories are affected.

Available anonymization options

Because of a change in architecture, the anonymous tracking options for the React Native tracker changed between version 2.x and version 4.x.

Feature	Version 4.x	Version 1.3 - 2.x
Full client-side anonymization	❌	✅
Client-side anonymization with session tracking	❌	✅
Toggle anonymous tracking at runtime	❌	✅
Server-side anonymization	✅	✅

1. Full client-side anonymization

In this case, you anonymize both client-side user identifiers and client-side session identifiers. This means disabling the session entity altogether.

Version 4.x

typescript

const tracker = await newTracker({
    namespace: 'appTracker',
    endpoint: COLLECTOR_URL,
    sessionContext: false, // Session entity won't be added to events
    platformContext: false, // Mobile entity won't be added to events

});

Identifier	Location in event	Included in event?
user_id	Atomic	✅ if set
domain_userid	Atomic	✅ if set
userId	Session entity	❌ no session entity
sessionId	Session entity	❌ no session entity
previousSessionId	Session entity	❌ no session entity
appleIdfa	Mobile (platform) entity	❌ no mobile entity
appleIdfv	Mobile (platform) entity	❌ no mobile entity
androidIdfa	Mobile (platform) entity	❌ no mobile entity
network_userid	Atomic	✅
user_ipaddress	Atomic	✅

Version 1.3 - 2.x

typescript

const tracker = createTracker(
    'appTracker',
    { endpoint: COLLECTOR_URL },
    {
        trackerConfig: {
            sessionContext: false,   // Session entity won't be added to events
            userAnonymisation: true, // Remove user identifiers from Subject and platform entity
        },
    }
);

Identifier	Location in event	Included in event?
user_id	Atomic	❌
domain_userid	Atomic	❌
userId	Session entity	❌ no session entity
sessionId	Session entity	❌ no session entity
previousSessionId	Session entity	❌ no session entity
appleIdfa	Mobile (platform) entity	❌
appleIdfv	Mobile (platform) entity	❌
androidIdfa	Mobile (platform) entity	❌
network_userid	Atomic	✅/❌ removed if you provided this in Subject
user_ipaddress	Atomic	✅/❌ removed if you provided this in Subject

2. Client-side anonymization with session tracking

This setting disables client-side user identifiers but tracks session information.

Version 4.x

Newer versions of the React Native tracker don't support client-side anonymization with session tracking. Unlike in version 2.x, you can't track the session entity with an anonymized userId.

Version 1.3 - 2.x

typescript

const tracker = createTracker(
    'appTracker',
    { endpoint: COLLECTOR_URL },
    {
        trackerConfig: {
            sessionContext: true,    // Session entity is tracked
            userAnonymisation: true, // User identifiers anonymized
        },
    }
);

With userAnonymisation: true and sessionContext: true, events include the session entity but the userId property is set to a null UUID (00000000-0000-0000-0000-000000000000). The IDFA identifiers are also removed from the platform entity.

Identifier	Location in event	Included in event?
user_id	Atomic	❌
domain_userid	Atomic	❌
userId	Session entity	❌ null UUID
sessionId	Session entity	✅
previousSessionId	Session entity	❌
appleIdfa	Mobile (platform) entity	❌
appleIdfv	Mobile (platform) entity	❌
androidIdfa	Mobile (platform) entity	❌
network_userid	Atomic	✅/❌ removed if you provided this in Subject
user_ipaddress	Atomic	✅/❌ removed if you provided this in Subject

Toggling anonymous tracking

When anonymous tracking is enabled or disabled using tracker.setUserAnonymisation(true | false), the tracker starts a new session. This results in a new sessionId.

3. Server-side anonymization

Server-side anonymization affects user identifiers set by the Collector: the network_userid property (set in the server-side cookie) and the user IP address. Use the serverAnonymization flag to prevent the Collector from setting these values.

Spelling

The new API uses the US English spelling "anonymization", rather than the British English "anonymisation" seen in the older API.

Version 4.x

typescript

const tracker = await newTracker({
    namespace: 'appTracker',
    endpoint: COLLECTOR_URL,
    serverAnonymization: true,
});

Version 1.3 - 2.x

typescript

const tracker = createTracker(
    'appTracker',
    { endpoint: COLLECTOR_URL },
    {
        emitterConfig: {
            serverAnonymisation: true,
        },
    }
);

Setting this flag adds an SP-Anonymous HTTP header to requests sent to the Collector. The Snowplow pipeline then anonymizes the network_userid and user_ipaddress identifiers.

Identifier	Location in event	Included in event?
user_id	Atomic	✅ if set
domain_userid	Atomic	✅ if set
userId	Session entity	✅
sessionId	Session entity	✅
previousSessionId	Session entity	✅
appleIdfa	Mobile (platform) entity	✅ if set
appleIdfv	Mobile (platform) entity	✅ if set
androidIdfa	Mobile (platform) entity	✅ if set
network_userid	Atomic	❌/✅ still present if you provided this in Subject
user_ipaddress	Atomic	❌/✅ still present if you provided this in Subject

4. Full anonymization

Full anonymization combines client-side and server-side anonymization to remove all user and session identifiers from events.

Version 4.x

Avoid configuring unwanted identifiers for full anonymization in version 4.x of the React Native tracker.

typescript

const tracker = await newTracker({
    namespace: 'appTracker',
    endpoint: COLLECTOR_URL,
    sessionContext: false,     // No session entity
    serverAnonymization: true, // Collector won't set network_userid or capture IP
    },
});

Identifier	Location in event	Included in event?
user_id	Atomic	✅ if set
domain_userid	Atomic	✅ if set
userId	Session entity	❌ no session entity
sessionId	Session entity	❌ no session entity
previousSessionId	Session entity	❌ no session entity
appleIdfa	Mobile (platform) entity	✅ if set
appleIdfv	Mobile (platform) entity	✅ if set
androidIdfa	Mobile (platform) entity	✅ if set
network_userid	Atomic	❌/✅ still present if you provided this in Subject
user_ipaddress	Atomic	❌/✅ still present if you provided this in Subject

Version 1.3 - 2.x

typescript

const tracker = createTracker(
    'appTracker',
    { endpoint: COLLECTOR_URL },
    {
        trackerConfig: {
            sessionContext: false,     // Session entity won't be added to events
            userAnonymisation: true,   // Remove user identifiers from Subject and platform entity
        },
        emitterConfig: {
            serverAnonymisation: true, // Collector won't set network_userid or capture IP
        },
    }
);

Identifier	Location in event	Included in event?
user_id	Atomic	❌
domain_userid	Atomic	❌
userId	Session entity	❌ no session entity
sessionId	Session entity	❌ no session entity
previousSessionId	Session entity	❌ no session entity
appleIdfa	Mobile (platform) entity	❌
appleIdfv	Mobile (platform) entity	❌
androidIdfa	Mobile (platform) entity	❌
network_userid	Atomic	❌
user_ipaddress	Atomic	❌