Fixing Overwritten Device ID Issue in Mixpanel Integration Code

Hi Gastón D., Please stand by as I search the Mixpanel knowledge base for an AI-powered answer. I normally take about 15 seconds or so. In case AI cannot answer your question, feel free to reach out to Mixpanel support at mixpanel.com/get-support. If you have follow-up questions for this thread, please tag me again with your question: @kapa.ai <follow-up question> 👋

Based on the information provided in the knowledge sources, it appears that your implementation is not following the recommended approach for handling device IDs in Mixpanel. Let me explain the issue and provide a solution.The problem you're experiencing, where the $device_id is being overwritten on every refresh, is likely because you're manually setting the $device_id property. Mixpanel's JavaScript SDK automatically generates and manages the $device_id for you, and you shouldn't need to set it manually.According to the Identifying Users (Simplified) documentation: "When using our Web or Mobile SDKs, Mixpanel will automatically generate a $device_id that's local to that user's device, and set that value as the distinct_id for the event. This ID will persist on all events tracked by that user on that device, until you call identify() or reset()."Instead of manually setting the $device_id, you should focus on properly identifying users when they log in. Here's a corrected version of your code that follows Mixpanel's best practices: LBKSimport mixpanel from 'mixpanel-browser';LBKStry { mixpanel.init(window.MIXPANEL_TOKEN, { debug: true, track_pageview: 'full-url', persistence: 'localStorage', persistence_name: 'session', }); } catch (error) { console.log(error); }LBKSexport const Mixpanel = mixpanel;LBKS// Call this function when a user logs in export function identifyUser(userId) { mixpanel.identify(userId); }LBKS// Call this function when a user logs out export function resetUser() { mixpanel.reset(); }LBKSIn this corrected version: 1. We remove the loaded callback and the manual $device_id setting. 2. We export functions to identify users and reset the identification when needed.When a user logs in, you would call identifyUser(userId) with their unique identifier. When they log out, call resetUser().This approach allows Mixpanel to properly manage the device ID and user identification, ensuring that events are correctly attributed to users across sessions and devices.For more detailed information on implementing user identification in Mixpanel, please refer to the Identifying Users (Simplified) documentation.

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Let me check the knowledge base for you again. One moment! 📚

I apologize for the confusion in my previous response. You're right to be concerned about a new $device_id being generated on every refresh, as this shouldn't be happening with the default Mixpanel configuration. Let's investigate this issue further.According to the Identifying Users (Simplified) documentation: "Mixpanel's SDKs will generate a $device_id and set that to distinct_id to associate these events to the same anonymous user. This ID will persist on all events tracked by that user on that device, until you call .identify() or .reset()."The $device_id should persist across page refreshes unless .reset() is being called or there's an issue with the persistence storage.Here are a few things to check: 1. Persistence: Ensure that the persistence is working correctly. You're using 'localStorage' for persistence, which is correct. Check if localStorage is available and functioning in your browser.2. Persistence Name: You've set persistence_name: 'session'. This might be causing issues. Try removing this line or changing it to a more permanent name like 'mixpanel'.3. Browser Settings: Check if your browser is set to clear localStorage on exit or if you're using any privacy extensions that might be clearing it.4. Check for .reset() calls: Ensure that mixpanel.reset() isn't being called unintentionally somewhere in your code.Here's a modified version of your code that might help diagnose the issue: LBKSimport mixpanel from 'mixpanel-browser';LBKStry { mixpanel.init(window.MIXPANEL_TOKEN, { debug: true, track_pageview: 'full-url', persistence: 'localStorage', loaded(mixpanel) { console.log('Mixpanel loaded'); console.log('Distinct ID:', mixpanel.get_distinct_id()); console.log('Device ID:', mixpanel.get_property('$device_id')); }, }); } catch (error) { console.error('Mixpanel initialization error:', error); }LBKSexport const Mixpanel = mixpanel;LBKSThis code will log the distinct_id and $device_id to the console when Mixpanel loads. If these values are changing on every refresh, there's likely an issue with persistence or an unintended reset occurring.If the problem persists after these changes, you may need to contact Mixpanel support for further assistance, as this behavior is not expected and may indicate a more complex issue with your specific setup or environment.Remember, you shouldn't need to manually set or manage the $device_id in most cases. Mixpanel should handle this automatically for you.

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