Reconcile Google Drive invoice PDFs with OpenAI, Sheets, Slack and Gmail

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1. Workflow Overview

How it works Watches a Google Drive folder and triggers automatically when a new invoice PDF is uploaded Extracts raw text from the PDF and passes each invoice through an OpenAI powered agent that ...

Best for

Invoice Processing automation workflows
AI Summarization automation workflows
advanced n8n builders looking for reusable templates

Tools used

n8n-nodes-base.code, n8n-nodes-base.googlesheets, n8n-nodes-base.slack, n8n-nodes-base.gmail, n8n-nodes-base.googledrive, n8n-nodes-base.extractfromfile, @n8n/n8n-nodes-langchain.agent, @n8n/n8n-nodes-langchain.lmchatopenai

Source and attribution

This workflow is cataloged by N8N Workflows and links back to its original n8n.io source page by Redowan Ahmed Farhan.

Original n8n.io source

1.1 Workflow description

Title: Reconcile Google Drive invoice PDFs with OpenAI, Sheets, Slack and Gmail
Workflow name: Reconcile Google Drive invoice PDFs with OpenAI, Sheets, Slack and Gmail

How it works

Watches a Google Drive folder and triggers automatically when a new invoice PDF is uploaded Extracts raw text from the PDF and passes each invoice through an OpenAI powered agent that returns structured fields like vendor, amount, due date, and line items Fans the enriched data to three parallel outputs: a Google Sheets log, a Slack alert for overdue invoices, and a weekly summary email to Finance via Gmail

Set up steps

Connect Google Drive, Google Sheets, Gmail, Slack, and OpenAI credentials (~15 minutes total) Works best with text based PDFs; scanned invoices need OCR upstream of the extraction step Keep full setup details and prompt tuning tips in the sticky notes inside the workflow

1.2 Logical Blocks

This catalog entry is organized from the workflow JSON. The node-level section below shows the executable blocks available for review before importing the template.

2. Block-by-Block Analysis

Block 1 - 04 | Code Split PDF Attachments into Items

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 2 - 07 | Code Parse and Enrich Invoice Data

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 3 - 08 | Google Sheets Append to Invoice Log

Type / Role: n8n-nodes-base.googleSheets - googleSheets
Config choices: Version 4

Block 4 - 10 | Slack Alert Finance on Overdue Invoices

Type / Role: n8n-nodes-base.slack - slack
Config choices: Version 2

Block 5 - 11 | Code Generate Weekly Summary Stats

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 6 - 12 | Gmail Email Weekly Report to Finance

Type / Role: n8n-nodes-base.gmail - gmail
Config choices: Version 2

Block 7 - Download file1

Type / Role: n8n-nodes-base.googleDrive - googleDrive
Config choices: Version 3

Block 8 - Extract from File1

Type / Role: n8n-nodes-base.extractFromFile - extractFromFile
Config choices: Version 1.1

Block 9 - AI Agent

Type / Role: @n8n/n8n-nodes-langchain.agent - agent
Config choices: Version 3.1

Block 10 - OpenAI Chat Model

Type / Role: @n8n/n8n-nodes-langchain.lmChatOpenAi - lmChatOpenAi
Config choices: Version 1.3

Block 11 - Google Drive Trigger1

Type / Role: n8n-nodes-base.googleDriveTrigger - googleDriveTrigger
Config choices: Version 1

Block 12 - Main Overview

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 13 - Section 1 Intake

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 14 - Section 2 AI Extraction

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 15 - Section 3 Parse Enrich

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 16 - Section 4 Output

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

3. Summary Table

Workflow	Reconcile Google Drive invoice PDFs with OpenAI, Sheets, Slack and Gmail
Complexity	advanced
Nodes	16
Categories	Invoice Processing, AI Summarization
Author	Redowan Ahmed Farhan
Published	20 May 2026

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/15840/15840.json as the source template for this automation.
2. Import the template into n8n

Open n8n, import the downloaded JSON, and review each node before activating the workflow.
3. Configure credentials and variables

Replace placeholder credentials, API keys, webhook URLs, account IDs, and environment-specific values with your own settings.
4. Test with sample data

Run the workflow manually or in a staging workspace, inspect node output, and confirm downstream systems receive the expected data.
5. Activate and monitor

Enable the workflow only after testing, then monitor executions, errors, and rate limits during the first production runs.

5. General Notes & Resources

Review imported nodes carefully before activation. This catalog entry is intended to help you inspect the workflow structure, understand required services, and find related templates faster.

Node names, credentials, schedules, webhook paths, and external service limits may need adjustment for your workspace.

Download workflow JSON Original n8n.io source Invoice Processing workflows AI Summarization workflows

Frequently asked questions

What does Reconcile Google Drive invoice PDFs with OpenAI, Sheets, Slack and Gmail do?

What do I need before importing this workflow?

Review the workflow JSON, configure any required credentials in n8n, and test the automation in a safe workspace before using it in production.

Can I customize this workflow?

Yes. Use the block-by-block analysis and the downloadable JSON to inspect each node, then adjust credentials, prompts, schedules, filters, or destinations for your Invoice Processing, AI Summarization use case.

Redowan Ahmed Farhan

14 workflows

Nodes

n8n-nodes-base.code n8n-nodes-base.googlesheets n8n-nodes-base.slack n8n-nodes-base.gmail n8n-nodes-base.googledrive n8n-nodes-base.extractfromfile @n8n/n8n-nodes-langchain.agent @n8n/n8n-nodes-langchain.lmchatopenai

Complexity

advanced

Published 20 May 2026

Likes 0

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Install path: /data/workflows/15840/15840.json

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Reconcile Google Drive invoice PDFs with OpenAI, Sheets, Slack and Gmail

Workflow preview

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - 04 | Code Split PDF Attachments into Items

Block 2 - 07 | Code Parse and Enrich Invoice Data

Block 3 - 08 | Google Sheets Append to Invoice Log

Block 4 - 10 | Slack Alert Finance on Overdue Invoices

Block 5 - 11 | Code Generate Weekly Summary Stats

Block 6 - 12 | Gmail Email Weekly Report to Finance

Block 7 - Download file1

Block 8 - Extract from File1

Block 9 - AI Agent

Block 10 - OpenAI Chat Model

Block 11 - Google Drive Trigger1

Block 12 - Main Overview

Block 13 - Section 1 Intake

Block 14 - Section 2 AI Extraction

Block 15 - Section 3 Parse Enrich

Block 16 - Section 4 Output

3. Summary Table

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

2. Import the template into n8n

3. Configure credentials and variables

4. Test with sample data

5. Activate and monitor

5. General Notes & Resources

Frequently asked questions