# Draft and approve Gmail replies with OpenAI and CustomJS: n8n workflow

> Started by another system calling it, and works across Gmail and Google Sheets. It hands the judgement calls to OpenAI.

Source: https://millionrounds.com/workflow/draft-and-approve-gmail-replies-with-openai-and-customjs-3 (Millionrounds; every figure on the page links to its filing or article)

[Automation library](https://millionrounds.com/workflows) · [Data collection](https://millionrounds.com/workflows?category=Data+collection#library)

# Draft and approve Gmail replies with OpenAI and CustomJS

Started by another system calling it, and works across Gmail and Google Sheets. It hands the judgement calls to OpenAI. 18 steps, 1 branch: a working afternoon to understand properly.

Medium Calls a model: OpenAI

[Download free](https://millionrounds.com/login?next=%2Fapp%2Fworkflow%2Fdraft-and-approve-gmail-replies-with-openai-and-customjs-3)

**18 steps** Medium: a working afternoon

**1** Branch: places the flow splits

**0** Loops or waits

**2** Services it connects to

## The flow

Starts it 2 Model 4 Logic 6 Service 6

The steps in the order they run, from what starts it.

- 1 **When clicking 'Execute workflow'** Manual trigger *Starts it*
- 2 **Webhook - Receive Approval** Webhook *Starts it*
- 3 **Get many messages** Gmail *Service*
- 4 **Extract Reply Data** Code *Logic*
- 5 **Filter No Reply Emails** Code *Logic*
- 6 **Reply to a message** Gmail *Service*
- 7 **Get Thread Context** Gmail *Service*
- 8 **Mark a message as read** Gmail *Service*
- 9 **Categorize Email** Open Ai *Model*
- 10 **Log Reply to Sheets** Google Sheets *Service*
- 11 **Route by Category** Switch *Logic*
- 12 **Draft Reply, Support** Open Ai *Model*
- 13 **Draft Reply, Sales** Open Ai *Model*
- 14 **Draft Reply, General** Open Ai *Model*
- 15 **Merge All Branches** Merge *Logic*
- 16 **Format Email Drafts** Code *Logic*
- 17 **Build Approval Page** Code *Logic*
- 18 **Upsert Approval Page** Pdf Toolkit *Service*

## How it's built

- **Starts on:** Another system calling it
- **Steps:** 18, with 1 branch
- **Size:** Medium: a working afternoon
- **Connects to:** Gmail, Google Sheets
- **Model:** OpenAI

## Questions

What does it need to run?

An n8n account, plus your own Gmail and Google Sheets accounts, and a key for OpenAI. You connect your own accounts after importing it; none are included.

What starts it?

It starts on another system calling it.

Does it use AI?

Yes. It calls OpenAI. Model calls are billed by the provider, not by n8n.

How long does it take to set up?

Plan an afternoon. 18 steps is enough that you should read each one before running it.

How do I import it?

Copy the workflow, open a new workflow in n8n and paste. The steps appear on the canvas, ready for your own accounts.

**Before you run it**

Nothing here has been tested by us. It is somebody's working automation, read and described from its own steps. Treat the connections it wants as a list of accounts it will touch, and read the 18 steps before you point it at anything that matters.

## Run it in n8n

- **Create your n8n account** Free to start. n8n is where the workflow runs. [Create an n8n account ↗](https://millionrounds.com/n8n)
- **Download the workflow** Free with a Millionrounds account. [Download free](https://millionrounds.com/login?next=%2Fapp%2Fworkflow%2Fdraft-and-approve-gmail-replies-with-openai-and-customjs-3)
- **Paste it into n8n** Open a new workflow in n8n and paste. Then connect your own accounts.

Stored with the author's traces removed: canvas notes, instance identifiers, saved credential names and any live document they had left behind.

## Connects to

Each opens the other workflows that use it.

[Gmail](https://millionrounds.com/workflows?service=Gmail#library)[Google Sheets](https://millionrounds.com/workflows?service=Google+Sheets#library)

## Workflows like it

Also data collection, with the same services where possible, closest in size first.

- [**AI calling agent with OpenAI** 18 steps · calls a model · Gmail, Google Sheets](https://millionrounds.com/workflow/ai-calling-agent-with-openai)
- [**AI-Powered Paperclip Task Assigner & Completion Tracker** 18 steps · calls a model · Gmail, Google Sheets](https://millionrounds.com/workflow/ai-powered-paperclip-task-assigner-and-completion-tracker)
- [**AI-powered customer feedback routing with Gmail and Slack** 18 steps · calls a model · Gmail, Notion](https://millionrounds.com/workflow/ai-powered-customer-feedback-routing-with-gmail-and-slack)
- [**Analyze Meta ads daily with Gemini and Google Sheets** 18 steps · calls a model · Gmail, Google Sheets](https://millionrounds.com/workflow/analyze-meta-ads-daily-with-gemini-and-google-sheets)
- [**Auto-reply to Instagram comments with Gemini and Google Sheets** 18 steps · calls a model · Google Sheets](https://millionrounds.com/workflow/auto-reply-to-instagram-comments-with-gemini-and-google-shee)
- [**Automated job listing aggregator & AI cover letter generator** 18 steps · calls a model · Google Docs, Google Sheets](https://millionrounds.com/workflow/automated-job-listing-aggregator-and-ai-cover-letter-generat)