AI-Powered Business Proposal Generator from Google Sheets to Google Docs - n8n Workflow

Sales Agencies & Consultants: Those needing to generate high volumes of custom proposals quickly.
Automation Specialists: Users seeking advanced examples of integrating LLMs with structured data processing within an n8n workflow.
Business Operations Teams: Groups looking to standardize complex document creation based on simple spreadsheet inputs.
n8n Users: Developers looking for effective n8n templates utilizing the Langchain AI integration suite.

Generating tailored business proposals is often a bottleneck for growing agencies. Manual creation is slow, inconsistent, and prone to error. This sophisticated automation solves this by creating a highly structured, scalable process powered by AI.

This specific n8n workflow is initiated simply by adding a new row to a Google Sheet (containing client name and job description). The core of this n8n automation leverages GPT-4o, configured via an n8n node to enforce a strict JSON output schema. This enforcement ensures that all generated components—like the executive summary, scope of work with specific bullet points, and four-month costing breakdown—are consistently formatted and instantly ready to populate a Google Docs template. The result is a professional, customized PDF proposal archived directly in Google Drive, significantly reducing turnaround time and freeing up sales teams. This is a powerful n8n template demonstrating complex, multi-step document generation.

This comprehensive n8n workflow operates in five main stages:

1. Trigger & Filtering: The n8n trigger, a Google Sheets node, constantly monitors a specified spreadsheet for new rows. Once a new client request is detected, a custom Code n8n node filters the results to ensure only the latest row is processed, preventing duplicate runs.


2. AI Orchestration: The data (clientName and jobDescription) is passed to the AI Agent n8n node. This agent is connected to the GPT-4o Model, a specific Memory buffer for context tracking, and critically, a JSON Output Parser n8n node. The system prompt provides explicit, detailed instructions (including formatting rules for bullet points and costing tables) to the AI.


3. Structured Generation: The AI processes the prompt and returns the proposal data as a clean, reliable JSON object, thanks to the Parser n8n node validating the output structure.


4. Document Population & Archiving: The resulting structured data is mapped to 13 specific placeholders (e.g., {{totalcost}}, {{scopeof_work}}) within a Google Docs template via the Populate n8n node. Immediately after population, the completed document is downloaded and uploaded/archived as a uniquely named file in a designated Google Drive folder.


5. Template Reset: The final step involves a Google Docs n8n node that immediately reverts the template back to its original placeholder state. This ensures the template is clean and ready for the next trigger event from the Google Sheets n8n trigger.

To deploy this powerful n8n workflow, follow these steps:

1. Import the n8n Template: Copy the provided JSON code and import it into your n8n instance using the 'New' -> 'Import from JSON' function.


2. Credential Setup: Ensure you have active credentials for:

1. Google Sheets Trigger Configuration: Replace YOURGOOGLESHEETID in the 'Trigger: New Sheet Row' n8n node parameters with the ID of your input sheet. Ensure the sheet has columns for clientName and jobDescription.


2. Google Docs Template: Create a template document in Google Docs. Add all required placeholders (e.g., {{executivesummary}}, {{total_cost}}). Update the 'Populate: Template Document' and 'Reset: Template Placeholders' n8n node with your template's Document ID.


3. AI Customization: Review the System Prompt in the 'AI Agent: Generate Proposal' n8n node. Customize brand names, currency (currently set to INR), and required scope of work to match your business.


4. Activate: Save and activate the n8n workflow.

Trigger: New Sheet Row (Google Sheets Trigger n8n node):
Function: Starts the n8n workflow when a new row is added to the specified Google Sheet.
Key Configuration: Polls the sheet every minute for changes.
Filter: Latest Row Only (Code n8n node):
Function: Filters the incoming sheet data to ensure that only the most recently added item is passed to the AI agent. This is crucial for stability with the Google Sheets n8n trigger.
AI Agent: Generate Proposal (Langchain Agent n8n node):
Function: Orchestrates the AI generation process. It injects client data into a highly detailed system prompt designed to enforce specific formatting and content requirements for a business proposal.
Key Configuration: Uses GPT-4o, references the JSON Output Parser, and provides strict guidelines for formatting section titles, bullet points (using the ● character), and line breaks (\n and \n\n).
Populate: Template Document (Google Docs n8n node):
Function: Takes the structured JSON output from the AI agent and performs 13 simultaneous find-and-replace actions within the Google Docs template.
Key Configuration: Specifies the Template Document ID and uses expressions to map JSON fields to document placeholders.
Archive: Save to Drive (Google Drive n8n node):
Function: Archives the completed proposal. It dynamically names the final file using the client name and current date.
Key Configuration: Requires setting YOUROUTPUTFOLDER_ID for storage.