AI-powered RAG Q&A chatbot with OpenAI, Google Sheets, Glide & Supabase

Automate AI-Powered RAG System with Contextual Q&A, Google Sheets Integration, and Glide Frontend—Powered by n8n, OpenAI, Supabase, and Google Apps Script. Tools & Services Used Glide (Frontend for user interactions) Google Sheets (Stores questions and answers) Google Apps Script (Forms + media upload handling) OpenAI (Embeddings + GPT-4 to rank and generate answers) Supabase (Optional for image hosting) n8n (Automation logic and backend glue) Workflow Overview This automation performs the following steps: Trigger: Webhook receives a user question from a Glide frontend. Fetch Data: Retrieves Q&A entries (and optionally, image URLs) from a connected Google Sheet. Rank Relevance: OpenAI Embeddings rank the relevance of stored questions to the new input. Top matches are passed to a GPT-4 prompt for answer generation. Generate Answer: GPT-4 creates a contextual answer using the best match. Optional: Includes media URL if attached to the matched answer. Response: Sends the formatted answer back to Glide frontend (text + optional image). Prerequisites Active accounts and API keys for: OpenAI (API key with GPT-4 and embedding access) Google Sheets (linked via Service Account or OAuth2 credentials) Glide App (with a form to submit questions) Supabase (optional, if hosting user-uploaded media) n8n Self-hosted (for community nodes and webhook access) How to Use This Template Step 1: Import the Template Upload the provided JSON into your self-hosted n8n instance. Requires installation of the Community Node: @n8n/n8n-nodes-openai-embeddings Step 2: Configure Credentials Webhook Trigger: Replace the Glide webhook URL with your actual endpoint from your app. Google Sheets Node: Set the spreadsheet ID and worksheet name to fetch your Q&A dataset. OpenAI Nodes: Insert your OpenAI API key. Confirm that both text-embedding-ada-002 (or similar) and gpt-4 are available. Supabase or Apps Script (Optional): Ensure image links are correctly formed in the Sheet. Step 3: Customize Prompts and Thresholds Update the OpenAI ranking prompt or similarity threshold in the Function or Code node. Tailor GPT-4 prompts to return concise or detailed answers based on your use case. Initial Test Run Simulate a Question: Trigger the Glide form with a sample question. Check n8n logs for: Matching score/ranking success Correct retrieval from Sheets GPT-4 answer generation Image URL handling (if enabled) Production Prep Add error-handling nodes for cases when Sheets are empty or GPT-4 fails. Set up logging via Google Sheets, Supabase, or external database. Rate-limit or debounce requests from Glide if needed. Use Cases Customer Support Portals: Offer instant Q&A with your business data. Internal Knowledgebase: Employees can query training manuals and SOPs. AI Concierge: Combine structured answers with friendly tone for guest interactions. Disclaimer Validate Glide form inputs before full deployment. Ensure your OpenAI and Google Sheets usage stays within quota limits.