What the dataLayer spec actually ships
Analytics implementation projects live or die on one artifact: a dataLayer spec that enumerates every event, every parameter, when each fires, and which marketing tags consume them. Agencies charge $3,000 to $10,000 to produce that document. This generator produces the same artifact in under a minute.
Pick a platform — Shopify, WooCommerce, Magento, BigCommerce, Rails, Next.js — and the marketing apps you run. You get the full GA4 enhanced-ecommerce event set (page_view, view_item, add_to_cart, begin_checkout, purchase, and nine more), each with its canonical parameters tagged required vs optional. You get Custom Event triggers ready to paste into GTM. You get platform-specific code snippets wired into real hook points — Shopify Liquid, WooCommerce PHP hooks, Magento observers, Next.js client effects. And you get a per-app mapping showing which GA4 event maps to which Meta Pixel / Google Ads / Klaviyo / TikTok / Pinterest standard event, including parameter notes.
Why the event names and parameters aren't invented
Every event name in this spec is the exact string GA4 recognizes as enhanced ecommerce. Every parameter key — transaction_id, currency, value, items, shipping, coupon — is documented by Google. Vendor-app mappings (fbq('track', 'Purchase') for Meta, ttq.track('CompletePayment')for TikTok) come straight from each vendor's own pixel documentation. If a claim in the output isn't in the vendor's docs, it isn't in here.
What about ongoing monitoring?
A one-shot dataLayer spec gets you shipped. Keeping the dataLayer firing correctly as your site changes — that's where most implementations drift. NiceLookingData's full audit runs 61 checks against your live GA4 property and GTM container, re-runs nightly, and emails you when something meaningful moves. Generate the spec here, then run a free audit to make sure your implementation stays honest.
For a full walkthrough of the required GA4 ecommerce events, the correct items array structure, and the 5 mistakes that silently undercount revenue, read GA4 Ecommerce Tracking: Setup, Events, and Common Mistakes. For the structural principles behind clean dataLayer pushes — flat objects, consistent event keys, no PII — read Data Layer Best Practices.