Manage construction work permits with GPT-4o, Google Sheets and Gmail

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1. Workflow Overview

Quick Overview This workflow accepts construction work permit requests via webhook, logs them to Google Sheets, uses OpenAI (gpt 4o mini) to detect conflicts against active permits, routes the requ...

Best for

Document Extraction automation workflows
AI Summarization automation workflows
advanced n8n builders looking for reusable templates

Tools used

n8n-nodes-base.stickynote, n8n-nodes-base.errortrigger, n8n-nodes-base.slack, n8n-nodes-base.if, n8n-nodes-base.googlesheets, n8n-nodes-base.code, n8n-nodes-base.gmail, n8n-nodes-base.scheduletrigger

Source and attribution

This workflow is cataloged by N8N Workflows and links back to its original n8n.io source page by Rahul Joshi.

Original n8n.io source

1.1 Workflow description

Title: Manage construction work permits with GPT-4o, Google Sheets and Gmail
Workflow name: Manage construction work permits with GPT-4o, Google Sheets and Gmail

Quick Overview

This workflow accepts construction work permit requests via webhook, logs them to Google Sheets, uses OpenAI (gpt-4o-mini) to detect conflicts against active permits, routes the request to a supervisor for approval via Gmail, then emails an approved permit document and monitors permits for expiry reminders.

How it works

Receives a work permit request via a POST webhook.
Appends the submission to a Google Sheets “log permit” tab and retrieves current permits from the Google Sheets “Permit Register” tab.
Sends the new request plus active permit data to OpenAI (gpt-4o-mini) to evaluate location/time/work-type conflicts and parses the JSON result into a permit record with an ID and calculated expiry.
If a conflict is detected, sends a Gmail rejection email to the worker with the conflict details.
If no conflict is detected, emails the supervisor via Gmail with approve/reject links and waits for the supervisor’s decision.
Updates the Google Sheets log status to approved or rejected, and for approvals generates an HTML permit document and emails it to the worker via Gmail.
Runs every 15 minutes to read approved permits from Google Sheets, then sends a 30-minute reminder or an expiry stop-work email via Gmail based on each permit’s expiry time.

Setup

Create Google Sheets OAuth2 credentials in n8n and replace YOUR_GOOGLE_SHEET_ID_HERE in all Google Sheets nodes, ensuring the sheet has tabs named “log permit” and “Permit Register” with the expected columns (including status and expiry fields).
Create Gmail OAuth2 credentials in n8n and replace the [SUPERVISOR-EMAIL] placeholder (and any hardcoded addresses) so supervisor and worker emails route correctly.
Add OpenAI API credentials in n8n and ensure the OpenAI node is configured to use an available model ID (set to gpt-4o-mini in this template).
Update https://YOUR-N8N-DOMAIN/webhook/permit-decision in the approval-link generator to your n8n base URL, then copy the live webhook URL for work-permit-request and configure it in your permit request form/app.
(Optional) Add Slack OAuth2 credentials and set the target channel to receive alerts from the workflow error trigger.

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 - Section: Error Handler

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

Block 2 - On Workflow Error

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

Block 3 - Slack – Send Error Alert1

Type / Role: n8n-nodes-base.slack - slack
Config choices: Version 2.3

Block 4 - Overview

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

Block 5 - Section – Intake & Logging

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

Block 6 - Section – AI Conflict Detection

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

Block 7 - Section – Supervisor Approval Gate

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

Block 8 - Section – Permit Issuance

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

Block 9 - Section – Expiry Monitoring

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

Block 10 - Credentials & Security

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

Block 11 - Route on Supervisor Decision

Type / Role: n8n-nodes-base.if - if
Config choices: Version 2.2

Block 12 - Update Permit Log – Approved

Type / Role: n8n-nodes-base.googleSheets - googleSheets
Config choices: Version 4.5

Block 13 - Generate Permit HTML Document

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

Block 14 - Email Approved Permit to Worker

Type / Role: n8n-nodes-base.gmail - gmail
Config choices: Version 2.1

Block 15 - Expiry Scheduler (Every 15 min)

Type / Role: n8n-nodes-base.scheduleTrigger - scheduleTrigger
Config choices: Version 1.2

Block 16 - Fetch Approved Permits from Register

Type / Role: n8n-nodes-base.googleSheets - googleSheets
Config choices: Version 4.5

Block 17 - Route on Expiry or 30-min Reminder

Type / Role: n8n-nodes-base.if - if
Config choices: Version 2.2

Block 18 - Send Permit Expiry Notification

Type / Role: n8n-nodes-base.gmail - gmail
Config choices: Version 2.1

Block 19 - Send 30-min Expiry Reminder

Type / Role: n8n-nodes-base.gmail - gmail
Config choices: Version 2.1

Block 20 - Update Permit Log – Rejected

Type / Role: n8n-nodes-base.googleSheets - googleSheets
Config choices: Version 4.5

Block 21 - Work Permit Form

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

Block 22 - Log Permit Submission to Sheet

Type / Role: n8n-nodes-base.googleSheets - googleSheets
Config choices: Version 4.5

Block 23 - Fetch Active Permits for Conflict Check

Type / Role: n8n-nodes-base.googleSheets - googleSheets
Config choices: Version 4.5

Block 24 - Aggregate Active Permits

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

Showing the first 24 of 31 workflow blocks. Download the JSON for the full node graph.

3. Summary Table

Workflow	Manage construction work permits with GPT-4o, Google Sheets and Gmail
Complexity	advanced
Nodes	31
Categories	Document Extraction, AI Summarization
Author	Rahul Joshi
Published	15 Jun 2026

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/16374/16374.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 Document Extraction workflows AI Summarization workflows

Frequently asked questions

What does Manage construction work permits with GPT-4o, Google Sheets 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 Document Extraction, AI Summarization use case.

Rahul Joshi

269 workflows

Nodes

n8n-nodes-base.stickynote n8n-nodes-base.errortrigger n8n-nodes-base.slack n8n-nodes-base.if n8n-nodes-base.googlesheets n8n-nodes-base.code n8n-nodes-base.gmail n8n-nodes-base.scheduletrigger

Complexity

advanced

Published 15 Jun 2026

Likes 0

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Install path: /data/workflows/16374/16374.json

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Manage construction work permits with GPT-4o, Google Sheets and Gmail

Workflow preview

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

Quick Overview

How it works

Setup

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - Section: Error Handler

Block 2 - On Workflow Error

Block 3 - Slack – Send Error Alert1

Block 4 - Overview

Block 5 - Section – Intake & Logging

Block 6 - Section – AI Conflict Detection

Block 7 - Section – Supervisor Approval Gate

Block 8 - Section – Permit Issuance

Block 9 - Section – Expiry Monitoring

Block 10 - Credentials & Security

Block 11 - Route on Supervisor Decision

Block 12 - Update Permit Log – Approved

Block 13 - Generate Permit HTML Document

Block 14 - Email Approved Permit to Worker

Block 15 - Expiry Scheduler (Every 15 min)

Block 16 - Fetch Approved Permits from Register

Block 17 - Route on Expiry or 30-min Reminder

Block 18 - Send Permit Expiry Notification

Block 19 - Send 30-min Expiry Reminder

Block 20 - Update Permit Log – Rejected

Block 21 - Work Permit Form

Block 22 - Log Permit Submission to Sheet

Block 23 - Fetch Active Permits for Conflict Check

Block 24 - Aggregate Active Permits

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