n8n + GPT-4o Proposal Generator: Google Slides & Gmail

Turn a sales call into a polished Google Slides proposal—automatically

This n8n + GPT-4o Proposal Generator workflow captures your proposal inputs from an n8n form, uses OpenAI (GPT-4o-mini) to generate structured proposal copy, fills a Google Slides template in Google Drive, and emails your client a link via Gmail—all with minimal manual effort.

What this workflow does

• Collects proposal inputs (client details, problem, solution, scope, cost, timeline, and client email) from an n8n form submission.
• Generates proposal content with OpenAI by sending the submitted notes to GPT-4o-mini and receiving structured JSON.
• Cleans and parses the AI response, then maps key sections into individual fields such as proposal title, tagline, summaries, scope items, next steps, and client details.
• Copies a Google Slides template stored in Google Drive, naming the new deck using the client name and the current day of the month.
• Replaces template placeholders in the copied deck (including the generated content plus the provided cost and timeline).
• Sends the client an email with a link using Gmail, so the proposal is ready to review immediately.

Use cases

• Speeding up proposal turnaround after a sales call by generating a ready-to-share Google Slides deck.
• Standardizing proposal formatting for SaaS operators and agencies using the same Slides template.
• Reducing manual writing and copy/paste errors for automation engineers managing client deliverables.

Technical details

• n8n nodes / tech stack: code, form trigger, OpenAI (GPT-4o-mini), google drive, google slides, gmail.
• Setup requirements: connect OpenAI API credentials; connect Google Drive/Google Slides OAuth and update the Google Slides template file ID; connect a Gmail account and ensure email sending to external recipients is enabled.
• Template placeholders: your Google Slides deck must include the exact placeholders used for replacement (e.g., {{proposal_title}}).