n8n Audit AI Citation Gaps: ChatGPT & Perplexity + Slack

Find out where your brand is mentioned vs. cited—then fix the content gaps

This weekly n8n workflow audits how often your brand is named and how often it’s backed by cited links in ChatGPT (with web search) and Perplexity. It then ranks the external pages earning those citations and logs a content-gap backlog in Google Sheets—so you know exactly what to build next.

What this workflow does

• Runs weekly on a schedule and reads one brand’s settings from Google Sheets (domain, sitemap path, competitors, sampling/notification settings).
• Analyzes your sitemap, including following a sitemap index one level down when needed, and scores URLs to select the most commercial pages to sample.
• Generates buyer-style questions using OpenAI from the themes of selected pages (without naming the brand), then expands them into multiple repeated runs.
• Checks both engines by sending each question to Perplexity and to the OpenAI Responses API (with web search), then normalizes results into a single record containing answer text and cited URLs.
• Calculates mention rate, citation rate, and stability per question and engine, and ranks external cited URLs (excluding your own domain).
• Classifies winning external pages with OpenAI (format, topic, and why they earn citations).
• Reports and logs results by generating a week-over-week HTML report, saving run history to Google Sheets, emailing via Gmail, and writing each citation gap as its own row in a “Content Gaps” backlog.
• Optionally alerts in Slack if citations drop significantly.

Use cases

• Validate whether your SaaS or product is only mentioned or truly cited with links in AI answers.
• Identify competitor vs. category pages that win citations and reverse-engineer why.
• Turn AI citation losses into an actionable Google Sheets backlog for content planning.

Technical details

• n8n nodes/stack shown: if, code, gmail, merge, slack, sticky note (plus the workflow’s use of OpenAI, Perplexity, and OpenAI Responses API with web search).
• Outputs: HTML trend report, Google Sheets history, email via Gmail, optional Slack notifications, and Content Gaps backlog rows.