Flag duplicate and risky AP invoices with Gmail, OpenAI and Supabase
Needs changesNeeds changes. This template uses 1 thing(s) that n8n 3.0 removes: AI Agent v1 (old agent modes). 1 breaking item(s) found. Static check, last run 2026-10-19.
What this workflow does
This AI workflow has 15 nodes and runs on Gmail events. Along the way it connects Gmail, OpenAI Chat Model, Supabase and Slack.
How it runs
Trigger: On Gmail events.
- Extract Invoice Data (AI Agent): runs an AI agent, with model: OpenAI — Extract; output parser: Invoice Data Schema
- Check Duplicates (Supabase): get many
- Count Duplicates (Code): runs custom JavaScript code
- Check Vendor History (Supabase): get many
- Merge All Context (Code): runs custom JavaScript code
- Assess Fraud Risk (AI Agent): runs an AI agent, with model: OpenAI — Risk; output parser: Fraud Risk Schema
- High Risk? (If): checks a condition and branches into true / false
- Alert Slack (Slack): uses Slack
- Log Invoice to Supabase (Supabase): insert
- Send Hold Notice (Gmail): uses Gmail
Services it uses
Before you upgrade to n8n 3.0
1 thing in this workflow is removed in n8n 3.0. Fix it before you upgrade:
- AI Agent v1 (old agent modes) in Extract Invoice Data (v1.8), Assess Fraud Risk (v1.8): replace with Latest AI Agent node (Tools Agent). For SQL Agent, use a Postgres or MySQL tool with a recent AI Agent.
- Also check Gmail Trigger below v1.4 runs as v1.4 (drafts skipped, max emails per poll).
| Removed in 3.0 | Replace with |
|---|---|
| AI Agent v1 (old agent modes) Extract Invoice Data (v1.8), Assess Fraud Risk (v1.8) | Latest AI Agent node (Tools Agent). For SQL Agent, use a Postgres or MySQL tool with a recent AI Agent. |
Nodes used (9)
- Gmail Trigger
n8n-nodes-base.gmailTrigger - AI Agent
@n8n/n8n-nodes-langchain.agent - OpenAI Chat Model
@n8n/n8n-nodes-langchain.lmChatOpenAi - Structured Output Parser
@n8n/n8n-nodes-langchain.outputParserStructured - Supabase
n8n-nodes-base.supabase - Code
n8n-nodes-base.code - If
n8n-nodes-base.if - Slack
n8n-nodes-base.slack - Gmail
n8n-nodes-base.gmail
From the author
🚀 How it works Monitors your AP inbox for incoming invoices, extracts structured data with AI, runs duplicate and vendor history checks against Supabase, then scores each invoice for fraud risk — routing suspicious ones to Slack and your AP team before any…