GA4 AI Monitoring — Built in Japan

CATCH SITE
PROBLEMS
BEFORE
YOUR CLIENTS DO

Ninjalens watches your clients' GA4 data 24/7 — detecting statistical anomalies, JS errors, and revenue drops — then sends AI-powered analysis straight to Slack. Under your brand.

Start 14-Day Free Trial See How It Works
14
Day Free Trial
$0
Infrastructure Cost
10
Clients per Agency Plan
24/7
Automated Monitoring
The Problem

Your clients notice problems before you do.

GA4 dashboards are overwhelming
Nobody has time to check GA4 every morning. Anomalies go unnoticed for days.
JS errors are invisible
Checkout breakages, cart errors, payment failures — silently costing your clients revenue. Existing error monitoring tools are built for developers and too complex to deploy.
Clients call you. Not the other way around.
Reactive support damages trust. Proactive detection wins long-term retainers.
#ninjalens-alerts
🥷
Ninjalens Today at 8:00 AM
🚨 Anomaly detected for client-shop.com
📊 Daily Report — Feb 26
Sessions▼ 34% vs last week (Z: -2.8)
Revenue▼ $1,240 (-41%)
JS Errors (Checkout)↑ 18 errors detected
CV Rate▼ 0.8% (was 2.1%)
🤖 AI Analysis: Checkout JS error likely blocking purchases. Immediate review recommended.
Features

Everything your agency needs
in one tool.

No BigQuery. No infrastructure. No engineers needed.

STATISTICAL ANOMALY DETECTION
Not just "down 10%" — Ninjalens uses Z-Score analysis to distinguish real anomalies from daily noise. Moving averages and week-over-week comparisons give you statistical confidence.
Z-Score + Moving Average
REAL-TIME JS ERROR DETECTION
A lightweight script detects JS errors, GTM failures, and 3rd-party breakages by page group — checkout, cart, product, homepage. Alerts fire via Slack within the hour.
Realtime API + Page Groups
AI-POWERED ANALYSIS
Gemini AI analyzes your GA4 data and tells you not just what happened — but why, and what to do next. Every daily report includes actionable recommendations.
Gemini 2.5 Flash
WHITE-LABEL REPORTS
Send Slack reports under your agency's brand name. Your clients think you built it. Charge them for the monitoring service and keep the margin — 10 licenses per Agency plan.
Agency Plan Feature
Setup

Live in 30 minutes.

No server. No code. Just a Google Spreadsheet.

01
Copy the Spreadsheet
Get your license key and make a copy of the Ninjalens Google Spreadsheet to your Drive.
02
Enter your API Keys
Add your GA4 Property ID, Gemini API key, and Slack Webhook URL to the Config sheet.
03
Add Error Tracking Script
Paste a one-line script tag to your site. Ninjalens auto-generates it from your page group settings.
04
Reports Come to You
Set your daily trigger time. Every morning, AI analysis arrives in Slack. Automatically.
Pricing

Simple, transparent pricing.

No per-event fees. No hidden costs. Your Gemini API key means you control the AI spend.

Starter
$49
/ month
1 License · 1 GA4 Property
  • Daily AI-powered Slack reports
  • Statistical anomaly detection (Z-Score)
  • Real-time JS error monitoring
  • Email notifications
  • Multi-language support (EN / JA)
  • Setup guide included
Start Free Trial
Most Popular
Agency
$499
/ month
10 Licenses · 10 GA4 Properties
  • Everything in Starter ×10
  • White-label Slack reports
  • Your brand name on every report
  • $49.9 per client — resell at your rate
  • Priority support
  • Looker Studio dashboard template
Start Free Trial

✦ 14-day free trial · No credit card required · Cancel anytime

Agency Margin Example
$499
Your monthly cost
10 client licenses
→
$200
Charge per client
as a monitoring fee
→
$1,501
Monthly margin
from 10 clients

Add it to your retainer. Bundle it with your reporting service. Your pricing, your margin.

FAQ

Common questions.

Yes — you bring your own Gemini API key. This means your data stays in your own Google ecosystem, and costs are typically under $10/month even for 10 clients. This is also a strong privacy selling point with your clients.
You receive one license key that can be activated on 10 separate Google Spreadsheets — one per client. Each client gets their own monitoring setup. With the white-label feature, reports arrive in their Slack under your agency's brand name.
None. Ninjalens runs entirely on Google Apps Script — Google's serverless infrastructure. No deployments, no downtime, no DevOps. If you can use Google Sheets, you can run Ninjalens.
Ninjalens only sends numerical GA4 metrics to Gemini — no PII, no customer names, no personal data. Your API keys and property IDs stay in your own Google Spreadsheet and are never stored on our servers.
After 14 days, your plan converts to a paid subscription via LemonSqueezy. No credit card is required to start the trial. You can cancel at any time before the trial ends.
Currently Ninjalens uses Gemini (gemini-2.5-flash) as its AI engine. Support for other models is planned for a future update. Gemini is free-tier friendly and delivers excellent analysis quality for GA4 data.
No changes to your existing GA4 configuration are needed. Ninjalens reads your GA4 data via the official Google Analytics Data API using your Property ID. For JS error detection, you add one lightweight script tag to your site — that's it.
Sessions, pageviews, active users, conversions, revenue, conversion rate, engagement rate, and top acquisition channels. For JS error monitoring, Ninjalens tracks errors by page group (home, product, cart, checkout, purchase, etc.) and by error type (own site, GTM, 3rd-party).
Yes. Ninjalens supports English and Japanese out of the box. You can switch languages in the Config sheet. Additional languages can be added to the Messages sheet by the user.
Ninjalens is built as a Google Apps Script library. Updates are applied automatically — you don't need to re-copy or redeploy anything. Your Config sheet settings are always preserved across updates.

START MONITORING.
BEFORE THEY CALL.

14-day free trial. No credit card. Setup in 30 minutes.

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