Generate Cold Emails & Sales Letters with OpenAI GPT & Google Docs via Chat

How it works Trigger: Listens for an incoming chat message Copy Assistant: Feeds the message (plus memory) into an OpenAI Chat Model and exposes two “tools”

Cold Email Writer Tool

Sales Letter Tool•

Tool execution: Depending on the user’s intent, the appropriate tool generates the copy • Save output: Writes the generated email or sales letter into your target document via the Update a document node

Set up steps • Configure your OpenAI Chat Model credentials in n8n (no hard-coded keys!) • Add and authenticate the Simple Memory credential (to keep context across messages) • Create Google Docs (or MS Word) credentials for the Update a document node • Ensure your Chat trigger is pointing at your incoming-message endpoint • Mandatory: Drop sticky-note annotations on each tool node explaining where to enter API keys and how to tweak prompts

Once everything’s wired up, send a test chat message like “Write me a cold email for a fintech startup” and watch the workflow spin up a polished draft in your document.

How to use

Import the workflow JSON into n8n.

Configure your Chat trigger (webhook or form) to receive incoming messages.

Send a chat prompt like:

“Write me a cold email for a B2B SaaS offering.”

The “Copy Assistant” custom GPT picks the right tool (Cold Email or Sales Letter).

Generated copy is written directly into your linked Google Doc or Word document.

Requirements OpenAI API Key (with Chat Completions & Custom GPTs enabled)

Custom Assistant created in your ChatGPT dashboard (Assistant ID pasted into the Chat Model node)

n8n instance (Cloud or self-hosted) with credentials set up for:

Simple Memory (to persist context)

Google Docs or Microsoft Word (for document output)

Customising this workflow Tweak system and user prompts inside the Copy Assistant node to fit your brand voice.

Swap in Slack, Teams or email nodes instead of a document writer to deliver copy where you need it.

Add or remove tools (e.g., “Follow-up Email Writer”) by duplicating the existing tool pattern.

Use sticky-note annotations on every node to explain where to enter API keys, Assistant IDs, or prompt tweaks.