Event Tracking Broken (core event stopped firing), Amplitude

Event Tracking Broken (core event stopped firing) for Amplitude stores. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it.

Metrics type: Key Metrics • Category: Analytics

At a glance

Event Tracking Broken (core event stopped firing) is a real-time alert card in Nerve Centre that fires when one of your essential Amplitude events, such as a purchase or add-to-cart, records zero occurrences for more than an hour during normal trading. A core event going completely silent is one of the most expensive blind spots a merchant can have, because it means a critical part of the customer journey is no longer being measured even if it is still happening. The card counts how many core events are currently in this broken state so you can restore instrumentation before reporting and funnels go dark.

What it counts	The count of active alerts where a core Amplitude event has recorded zero occurrences for more than one hour during normal trading.
Sample type	Real-time alert evaluation against Amplitude core event counts, refreshed continuously in Nerve Centre.
Why it matters	A silent core event silently corrupts every funnel, conversion, and retention metric that depends on it. Catching it fast protects the integrity of your whole analytics layer.
Reading the value	A value above zero means at least one core event has stopped firing. Open the alert to see which event went silent and exactly when it last fired.
Currency	count
Time window	RT
Alert trigger	core event count = 0 for >1h
Sentiment key	amp_alert_tracking_broken
Roles	owner, marketing

Calculation

Nerve Centre watches the count of each event you designate as core in Amplitude. When a core event records zero occurrences for more than one hour during a period when it would normally be firing, the alert triggers and is added to the active count shown on this card. The card value is the number of core events currently in the broken state. See the At a glance summary above for what the card tracks and the worked example below for a typical reading.

Worked example

A representative reading of Event Tracking Broken (core event stopped firing) for a typical merchant on Amplitude. The store treats purchase and add_to_cart as core events. On 21 Mar 26 at 09:15 the purchase event count drops to zero while add-to-cart, page views, and sessions all keep flowing normally. By 10:20 it has stayed at zero for over an hour, so the alert fires and the card reads 1. Because everything else is healthy, the team rules out a site outage and Vortex Mind traces the silence to a release that renamed the purchase event on the thank-you page, so events were still firing but under a name Amplitude no longer recognised as core. Ask Viq is used to ask, in plain English, when purchase last fired and how many orders the platform recorded in the same gap, which quantifies the tracking blind spot before the event name is corrected.

Sibling cards merchants should reference together

Card	Why merchants reach for it
amp_core_events_firing	Confirms which core events are currently firing and which are not.
amp_alert_event_volume_drop	Shows whether overall volume dropped or just one event went silent.
amp_event_taxonomy_drift	Surfaces renamed or unexpected events that can cause a core event to vanish.
amp_event_volume	Gives the total event context around the silent core event.
amp_health_score	Summarises overall instrumentation health behind the alert.

Reconciling against Amplitude

Where to look in Amplitude’s own dashboard:

Open Event Segmentation, chart the affected core event by hour, and look for the point where the count drops to zero. Amplitude’s own anomaly detection and Alerts can also be configured to watch for an event reaching zero; compare what Nerve Centre flagged against Amplitude’s event trend and any native alert in the same window. Confirm the exact event name and the trading hours match the Vortex IQ profile before concluding the readings disagree.

Why the Vortex IQ value may legitimately differ:

Reason	Direction	What to do
Period boundary. Nerve Centre uses a rolling one-hour silence window; Amplitude charts may aggregate by day.	Variable	Chart the event by hour to align.
Time zone. Amplitude uses the project time zone; Vortex IQ aligns to the merchant reporting time zone.	Marginal	Confirm time zone match.
Filter and event scope. A renamed or re-cased event may still be firing under a different name not flagged as core.	Variable	Verify the exact core event name and casing.

Cross-connector reconciliation: when this fires, complement the Amplitude event view with your ecommerce platform’s own order or cart records for the same hour to confirm whether the action is still happening untracked. For divergence investigations, use Vortex Mind.

Known limitations / merchant FAQs

Q: How quickly does this alert fire after an event goes silent? The condition requires more than one hour of zero counts during normal trading, so the alert surfaces shortly after that hour elapses on the next Nerve Centre refresh. The one-hour buffer prevents false alarms from brief quiet spells.

Q: Why did the alert not fire even though my event looks broken in Amplitude? Often the event name or casing differs between what is flagged as core in the Vortex IQ profile and what Amplitude is receiving, or the silence fell inside genuinely quiet trading hours. Verify the exact core event name and the trading-hours window.

Q: My event still shows volume but the alert fired anyway. Why? A renamed event can keep total volume looking healthy while the specific core event Vortex IQ watches reads zero. Check the taxonomy drift card to spot a rename, then update the core event mapping.

Q: Can I customise which events are core and the silence threshold? Yes, the set of core events and the one-hour silence window are configurable per profile in the Alert Rules tab. Define core events to match the actions that actually drive your business rather than relying on the generic default.

---

Tracked live in Vortex IQ Nerve Centre

Event Tracking Broken (core event stopped firing) is one of hundreds of KPI pulses Vortex IQ tracks across Amplitude and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English.

Start for free or book a demo to see this metric running on your own data.