Multi Channel AI automation

Job Title: Multi-Channel AI Automation Expert (Gmail + WhatsApp to Google Sheets via n8n) Description: I am looking for an experienced automation freelancer to build a cost-effective, multi-channel AI workflow. Currently, my client inquiries arrive via Gmail and WhatsApp Business. The product and pricing data lives in a Google Sheet. My previous AI setup kept hallucinating data—it was pulling wrong rows and accidentally leaking internal information like "Supplier Name" and wholesale costs into the offers. I need a robust system with strict data guardrails built on n8n (self-hosted or cloud) to keep monthly operational costs near zero and completely avoid expensive platforms like Zapier or Make.com. Requirements & Workflow Logic: 1. Gmail Workflow: - Trigger when a new inquiry email arrives in my inbox. - Look up the corresponding item/pricing in the Google Sheet using strict matching. - Isolate the data: The workflow must hide or filter out internal columns (like Supplier Name) so the AI cannot see them. - Use a raw LLM API (OpenAI or Anthropic) to draft a professional offer email based on the filtered data. - Save the final output as a GMAIL DRAFT. I want a "human-in-the-loop" safety net where I manually review and hit send. 2. WhatsApp Workflow: - Integrate incoming messages using the official WhatsApp Cloud API (Meta Developers console). - Match the query against specific product rows in Google Sheets. - Strict Guardrails: If the AI matches the data with 100% confidence, reply to the client automatically with the retail offer. If the query is ambiguous, vague, or a low-confidence match, the AI must trigger a polite fallback message ("Let me look into that specific item for you and get right back to you!") instead of guessing or leaking data. Skills Needed: - Advanced n8n workflow development - Google Sheets API integration - Meta Developer Console & WhatsApp Cloud API setup - OpenAI / Anthropic API formatting & prompt engineering (system prompt constraints) To Apply: Please briefly explain whether you recommend n8n Cloud or a self-hosted n8n setup for this specific use case, and confirm your experience with the Meta WhatsApp Cloud API.