Server-side GTM sanity-checked end-to-end.
A server container is just a router. Without the right Client + transport URL + forwarding tags, every GA4 hit silently drops into the void. The audit walks the four checks that prove your sGTM is actually doing work.
Server-side GTM costs $30–200/month to run on Cloud Run, and a meaningful fraction of containers we audit are either misrouting traffic or doing nothing useful. The four failure modes are silent: no GA4 Client means inbound /g/collect requests 400 at the door, no transport_url means your web GA4 keeps shipping browser-direct to Google and the server container is decorative, no forwarding tags means data lands in the server and disappears, no logging means you cannot tell that any of the previous three are happening. Marketing leaders sign off on sGTM because their agency said it improves measurement under iOS/Safari. Six months later nobody can answer "are we actually getting more conversions?" — because the container has no observability and the server-side hits never made it past the front door. The audit answers that in 60 seconds.
- Detects whether your sGTM container has the GA4 Client tag installed — without it, every inbound `/g/collect` request 400s and the entire server-side stack is decorative.
- Verifies your web GA4 Configuration tag has `transport_url` set to your sGTM first-party endpoint. Missing this means the browser keeps shipping events directly to Google and your server container never sees the data.
- Counts forwarding tags in the server container — GA4, Google Ads, Meta CAPI, etc. — and flags the "Clients but no Tags" anti-pattern where the server receives data and silently drops it on the floor.
- Confirms Cloud Logging is enabled at INFO level so failed hits + dropped events leave a trace. Without logging, the next "why are conversions down?" investigation has no breadcrumbs to follow.
- Reports the four check results as a one-screen sGTM health summary — pass/fail per check, with the exact menu path and field value to fix each one. No tab-switching to Google's sGTM docs.
Web GA4 has no transport_url — server container is decorative
You are paying for a Cloud Run sGTM instance that receives zero traffic. Every browser hit ships directly to google-analytics.com instead of routing through your first-party endpoint. The Safari/iOS conversion-recovery story you bought sGTM for is not happening. Expect the same iOS-tracking-prevention attribution gap you had pre-sGTM, on top of the Cloud Run bill.
In your web GTM container → Tags → GA4 Configuration tag → Fields to set, add a field with name `transport_url` and value `https://analytics.yourdomain.com` (your first-party sGTM endpoint). Publish the web container, wait 5 minutes, then in sGTM Preview verify inbound `/g/collect` requests start arriving and are claimed by the GA4 Client. Run the audit again to confirm the check turns green.
Hire a web analyst. Or install one.
Server-side GTM is one of 10 high-stakes chores the agent covers end-to-end. Your first audit is free — and the agent keeps watching every night, so the next time server-side gtm drifts, you hear it from us before it costs you.