Session Capture Broken (replay count collapsed), FullStory

Session Capture Broken (replay count collapsed) for FullStory 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: Nerve Centre

At a glance

Session Capture Broken (replay count collapsed) is the data-integrity alarm for the FullStory connector itself. It fires when captured session volume falls more than a quarter below the 7-day baseline, the signature of the FullStory snippet failing to load rather than a real traffic drop. This is the alert that protects every other FullStory card: if capture has collapsed, the frustration and conversion numbers are reading a partial site and cannot be trusted until the snippet is fixed.

What it counts	Real-time alerts raised when captured session volume drops more than 25% below the 7-day baseline, indicating a likely capture failure.
Sample type	Backend API data from FullStory, evaluated continuously against the alert rule.
Why it matters	A capture collapse silently blinds every other FullStory metric. Catching it fast prevents teams from acting on, or being reassured by, numbers built on missing data.
Reading the value	Each entry is a fired alert. Cross-check against traffic from analytics: if traffic held but capture fell, the snippet is broken somewhere.
Currency	count
Time window	RT
Alert trigger	session count down >25% vs 7D baseline
Sentiment key	fs_alert_tracking_broken
Roles	owner, marketing

Calculation

Calculated automatically from your FullStory data. Vortex IQ compares current captured-session volume against the trailing 7-day baseline and raises an alert when it falls more than 25% below, which typically signals a snippet or capture failure rather than a demand change. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.

Worked example

A representative reading of Session Capture Broken (replay count collapsed) for a typical merchant on FullStory. Suppose an alert fires on a Wednesday morning. Captured sessions are down 40% against the 7-day baseline, yet ad clicks and analytics sessions are flat. That mismatch is conclusive: traffic is fine, capture is broken. The cause turns out to be a tag-manager publish that dropped the FullStory container from product templates. Restoring it brings capture back. Without this alert, days of frustration data would have quietly gone missing. For deeper investigation, use Vortex Mind to compare capture against traffic; for natural-language exploration, ask Ask Viq whether tracking is broken.

Sibling cards merchants should reference together

Card	Why merchants reach for it
fs_session_count	The captured-session count this alert watches.
fs_replay_capture_coverage	The coverage ratio that confirms the gap.
fs_health_score	Drops when capture health fails.
ful_sessions	The analytics session count to cross-check against.

Reconciling against the vendor’s own dashboard

Where to look in FullStory’s own dashboard:

FullStory shows captured session volume in session search and surfaces capture diagnostics in settings. To reconcile, compare the Vortex IQ baseline window against FullStory’s own volume trend over the same dates.

Why the Vortex IQ value may legitimately differ:

Reason	Direction	What to do
Baseline window. A 7-day baseline behaves differently from a longer FullStory trend view.	Variable	Align the baseline window.
Genuine traffic drop. A real demand fall can trip the alert even though capture is fine.	Variable	Cross-check against analytics traffic.
Sampling change. A change to the capture sampling rate lowers volume without a defect.	Lower	Confirm the sampling rate.

Cross-connector reconciliation: complement with capture coverage and the analytics session count. For divergence investigations, use Vortex Mind.

Known limitations / merchant FAQs

Q: How often does Session Capture Broken update? It evaluates in near real time against the alert rule, so entries appear as the drop is detected rather than on the standard refresh cadence.

Q: Could this fire when nothing is broken? Yes, a genuine traffic slump or a planned sampling change can trip it. That is why the first step is always to cross-check captured volume against your analytics traffic for the same period.

Q: Why does my FullStory dashboard show a different trend? The most common reasons are the baseline window, a real traffic change, and sampling settings. Align these before assuming a real divergence.

Q: Can I customise the alert threshold? Yes, the 25% drop alert threshold and baseline window are configurable per profile in the Alert Rules tab. Tune them to your traffic variability.

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Tracked live in Vortex IQ Nerve Centre

Session Capture Broken (replay count collapsed) is one of hundreds of KPI pulses Vortex IQ tracks across FullStory 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.