Postgres + GPT-4.1 SEO What-If Webhook for Traffic Impact

Simulate SEO traffic impact with a Postgres-backed “what-if” webhook—then generate an executive forecast with GPT-4.1

This n8n workflow exposes a header-authenticated webhook that lets you model how merging, creating, or removing pages would affect SEO traffic—using baseline metrics from Postgres—and then converts the forecast into a validated executive narrative via OpenAI (GPT-4.1).

What this workflow does

• Receives a POST request on /seo-what-if-simulate using header authentication.
• Validates inputs (tenant/site, horizon, and action types like merge/new/remove) and returns structured 400 responses when rules fail.
• Loads the latest per-page SEO metrics snapshot from Postgres for the provided tenantId and siteId; returns structured 404 if no snapshot exists.
• Builds a baseline site model (totals, clusters, CTR calibration, and existing cannibalization), then runs merge, new-page, and removal simulations in parallel to compute month-by-month deltas and risk flags.
• Generates a forecast with expected/low/high click bands, a verdict, confidence, and per-action breakdown and warnings.
• Uses OpenAI via a LangChain LLM chain to turn the computed forecast into an executive narrative, validating the returned JSON with a deterministic fallback if needed.
• Audits every run by inserting the simulation run and full result back into Postgres, then responds with a 200 JSON payload.

Use cases

• Estimate traffic outcomes before approving SEO page consolidation (merge) or expansions (new pages).
• Quantify cannibalization risk when removing or redirecting underperforming pages.
• Give SaaS operators and automation engineers an API-driven, repeatable SEO scenario planner.

Technical details

• Webhook (route: /seo-what-if-simulate) + if validation logic + set/code transformations
• Postgres integration for metrics snapshot lookup and run/result auditing (seo_page_metrics and workflow tables)
• Parallel merge/new/remove simulation (merge/coordinated logic)
• OpenAI (GPT-4.1) via LangChain + deterministic JSON validation fallback