What does the error errTooManyIds mean in the Identify event?

Hi Felipe E., 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> 👋

I’m sorry, but the knowledge sources provided don’t mention an error named errTooManyIds for the Identify event. They do note related limits and behaviors—like the 500-ID-per-identity-cluster limit in Original ID Merge, which, when exceeded, prevents further IDs from being merged into that user’s cluster—but no specific error code by that name is documented. [On Original; FAQ (Original)]If you’re seeing errTooManyIds, it may indicate you’ve reached an identity limit (e.g., 500 IDs per cluster on Original ID Merge). I recommend checking which ID Merge API your project uses and reviewing the cluster size or recent identity merges. If needed, contact Mixpanel Support with an example user and timestamp. [FAQ (Identity); Mechanism (Original)]

ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.

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

Short answer: You’re likely hitting the 500-IDs-per-identity-cluster limit in the Original ID Merge API. When a cluster reaches 500 distinct IDs (e.g., repeated resets generating new device IDs), further merges/identify attempts can fail.How to avoid/fix: - Reduce unnecessary reset() calls - Only call reset() when there’s a definite intent to switch to a different user (e.g., user clicks “Sign up” vs “Log in”), to avoid generating a new anonymous device ID each time. [Best practices (Original); Example flows (Original)] - Audit your identity flows - Ensure identify(<user_id> ) is called at registration/login and when reopening in a logged-in state; avoid creating profiles for anonymous users. [Best practices (Original)] - Check if users are sharing devices - If many different users share one device and you call reset() on each logout, you can eventually hit the 500-ID limit. Consider minimizing resets where possible if you don’t truly need multi-user device support. [On Original] - Investigate hot shard/ID issues - Verify you’re not accidentally identifying everyone with a static string (e.g., 'user_id'), which would incorrectly cluster identities. [Hot shard – changing your implementation] - If already at the limit - Once a cluster reaches 500 IDs, new IDs can’t be merged into it and will appear as duplicate users (“orphaned”). You’d need to prevent further resets and consider longer-term options (e.g., a new project using Simplified ID Merge, which removes the 500-ID cap but only allows one $user_id per cluster). [On Original; Identity overview]Note: The docs don’t mention an error named errTooManyIds explicitly, but the behavior matches the documented 500-ID cluster cap on the Original API. [FAQ (Identity)]

ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.