Automate invoice processing from Gmail with Azure GPT-4.1 and human verification
Needs changesNeeds changes. This template uses 1 thing(s) that n8n 3.0 removes: Write Binary File. 1 breaking item(s) found. Static check, last run 2026-10-19.
What this workflow does
This AI workflow has 11 nodes and runs on Gmail events. Along the way it connects Gmail and Azure OpenAI Chat Model.
How it runs
Trigger: On Gmail events.
- Is this PDF? (If): checks a condition and branches into true / false
- Merge: merges the data from its input branches
- Information Extractor: extracts structured fields from text with AI, with model: Azure OpenAI Chat Model
- Error Handler (Stop and Error): stops the run with an error
- Save PDF Locally (Write Binary File): uses Write Binary File
- If: checks a condition and branches into true / false
- Send a message (Gmail): send and wait for a reply
- Invoice Saved Message (Gmail): uses Gmail
- Manual Verification (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:
- Write Binary File in Save PDF Locally: replace with Read/Write Files from Disk.
- Also check Gmail Trigger below v1.4 runs as v1.4 (drafts skipped, max emails per poll).
- Also check Always Output Data on multi-output nodes (If/Switch) now adds an empty item only when every output is empty.
Rather not rewrite it? Many of these flows can be rebuilt in Make (free plan).
| Removed in 3.0 | Replace with |
|---|---|
| Write Binary File Save PDF Locally | Read/Write Files from Disk |
Nodes used (8)
- Gmail Trigger
n8n-nodes-base.gmailTrigger - If
n8n-nodes-base.if - Write Binary File
n8n-nodes-base.writeBinaryFile - Merge
n8n-nodes-base.merge - Information Extractor
@n8n/n8n-nodes-langchain.informationExtractor - Gmail
n8n-nodes-base.gmail - Azure OpenAI Chat Model
@n8n/n8n-nodes-langchain.lmChatAzureOpenAi - Stop and Error
n8n-nodes-base.stopAndError
From the author
This workflow contains community nodes that are only compatible with the self-hosted version of n8n. This n8n workflow automates invoice management by integrating Gmail, PDF analysis, and Azure OpenAI GPT-4.1, with an optional human verification step for…