Quoting & Invoicing Automation

The Problem

Every enquiry arrived on WhatsApp as free text and someone on the team priced each job by hand and typed the quote out. Turnaround was about a day and work was being lost to whoever replied first. An earlier attempt had also been sending some customers two quotes for the same order.

Architecture & Approach

• GoHighLevel as the system of record across thirteen pipeline stages and nineteen custom fields, holding contacts, opportunities, conversations and the team dashboard
• n8n as the orchestration layer, self hosted, with twenty three published workflows covering intake, pricing, approval, invoicing and exception handling
• An LLM step that reads the free text a customer wrote and extracts the job detail into clean structured JSON, in whatever layout it arrives
• Live stock and pricing lookups against the client point of sale system over its API, so the AI never invents a number
• A durable queue behind every webhook, with the endpoint acknowledging first and doing the slow work in the background
• An atomic idempotency claim on the enquiry ID, written as a single insert that fails if the record already exists, so a retry can never produce a second quote
• Human approval gate before any quote reaches a customer, then automated PDF generation, invoice and payment link
• Supporting workflows for stuck order detection, restock notification, change requests and backlog re engagement