sGTM Preview Header config lets you see all incoming server-side requests in the sGTM debugger, not just those from the web container. Review and debug requests from CRMs, backend systems, mobile apps, APIs, and webhooks to check how your server GTM setup processes the data and whether the expected tags fire.
sGTM Preview Header config is available on Stape Free plans and higher. You can find it in the Power-ups tab in your Stape account.
Open your Stape account → Choose your recent sGTM container → Click Power-ups → Find sGTM Preview Header config and click Use.

sGTM Preview Header config stores your current X-Gtm-Server-Preview value in Stape for a test session. Stape uses this value to send incoming test requests to your open sGTM preview session, so they appear in the debugger.
You can also limit testing by webhook path or IP address. This lets you send selected test requests to preview while regular traffic continues to your sGTM container as usual.
X-Gtm-Server-Preview header in each backend system, app, API, or webhook tool. This also helps when an external tool does not let you add custom HTTP headers.sGTM Preview Header config shows requests from CRMs, order systems, payment tools, and apps in the sGTM debugger. Inspect the incoming data and fix setup issues before publishing your changes.
One of the ways to use server-side tracking is sending data directly from your server endpoint to the server GTM container. This guide will show how you can send requests to the GTM server container with webhooks and how to see and test webhook data in the server Google Tag Manager container. We’ll also go over some common scenarios where it makes sense technically and practically speaking.
Track offline conversions by sending CRM data to Facebook Conversions API via webhooks. Easily set up with GTM server containers for accurate attribution. The most popular way of integrating Facebook Conversions API is using the Google Tag Manager server container. But there are other ways to do that: using Zapier, direct integration, integration with the CRM using webhooks, and much more.
Learn how to debug server-side tracking with Stape’s tools, including sGTM Debugger, logs, and monitoring, to ensure accurate and efficient data tracking.