n8n Workflow: Turn Discovery Calls into OpenAI Proposals

Turn discovery call notes into an OpenAI-powered proposal draft—automatically

This n8n workflow captures your discovery call details from an n8n Form, logs them to Google Sheets, and—when the outcome is “Send proposal”—uses OpenAI to generate structured proposal copy and milestones. It then creates a Gmail draft email that links to a proposal Google Doc for fast client-ready sending.

What this workflow does

• Collects intake data via an n8n Form submission (discovery call details).
• Logs calls to Google Sheets by appending submitted call data into a “Calls” sheet (or a sheet you configure).
• Checks the call outcome: if the outcome is not “Send proposal”, the workflow stops.
• Generates proposal content with OpenAI (GPT-5.4) to produce structured sections such as:
  • Proposal title
  • Problem pitch
  • Solution pitch
  • Platform summary
• Creates project milestones and timelines with OpenAI (gpt-5-mini) using the proposed solution and a rough timetable, generating four milestones.
• Drafts the client email in Gmail using content derived from a Google Slides page, including a link to a proposal document in Google Docs.

Use cases

• SaaS and services teams who want to move from discovery calls to proposal drafts in minutes.
• Automation engineers and n8n users building repeatable client onboarding pipelines.
• Teams standardizing proposal structure while still tailoring to each call’s intake details.

Technical details

• n8n Form Trigger
• if conditional logic on the call outcome (“Send proposal”)
• Google Sheets (append to “Calls” sheet)
• OpenAI: GPT-5.4 for proposal copy; gpt-5-mini for milestones
• Google Slides (retrieves a page before composing the email)
• Gmail (creates a draft email with recipient mapping from client email)
• n8n-nodes-langchainagent (as referenced in the workflow stack)

Setup note: you’ll connect OAuth for Google Sheets, Gmail, and Google Slides, add your OpenAI API credential, and ensure the email body points to a valid Google Docs document ID.