Automate invoice processing & stock management with AI, Gmail, Sheets & Slack
Ready for 3.0Ready for 3.0. This template uses no nodes that n8n 3.0 removes. No removed nodes, versions or helpers found. Static check, last run 2026-10-19.
What this workflow does
This AI workflow has 12 nodes and runs on Gmail events. Along the way it connects Gmail, OpenAI Chat Model, Google Sheets and Slack.
How it runs
Trigger: On Gmail events.
- Extract from File: extracts data from a file (pdf)
- Extract Invoice Record (AI Agent): runs an AI agent, with model: OpenAI Chat Model; output parser: Structured Output Parser
- Sales Order Creation (Google Sheets): append
- Stock & Shortage Check (Google Sheets): uses Google Sheets
- If: checks a condition and branches into true / false
- Create Purchase Requisition (Google Sheets): append
- Create Work Order (Google Sheets): append
- Send a message (Gmail): uses Gmail
- Send Order Summary (Slack): uses Slack
Services it uses
Before you upgrade to n8n 3.0
Nothing in this workflow is removed in n8n 3.0, so it should import and run after the upgrade.
- Still check Gmail Trigger below v1.4 runs as v1.4 (drafts skipped, max emails per poll) (Gmail Trigger).
Nodes used (9)
- Gmail Trigger
n8n-nodes-base.gmailTrigger - Extract from File
n8n-nodes-base.extractFromFile - Structured Output Parser
@n8n/n8n-nodes-langchain.outputParserStructured - OpenAI Chat Model
@n8n/n8n-nodes-langchain.lmChatOpenAi - Gmail
n8n-nodes-base.gmail - AI Agent
@n8n/n8n-nodes-langchain.agent - Google Sheets
n8n-nodes-base.googleSheets - If
n8n-nodes-base.if - Slack
n8n-nodes-base.slack
From the author
✅ What problem does this workflow solve? Order processing often involves manual invoice reading, stock checking, and back-and-forth communication between procurement and operations teams. This workflow automates the entire procurement decision flow — from…