Automate Invoice Creation and Delivery with Google Sheets, Invoice Ninja, and Gmail

This n8n workflow automates the process of creating and delivering invoices based on new data in a Google Sheet. It streamlines your billing process by automatically generating invoices in Invoice Ninja and sending them via Gmail, ensuring timely and accurate client communication.

What it does

1. Monitors Google Sheet: Listens for new or updated rows in a specified Google Sheet.
2. Creates Invoice in Invoice Ninja: Uses the data from the Google Sheet to create a new invoice in Invoice Ninja via its API.
3. Sends Invoice via Gmail: Delivers the newly created invoice to the client's email address using Gmail.

Prerequisites/Requirements

To use this workflow, you will need:

• n8n Account: A running instance of n8n.
• Google Sheets Account: A Google Sheet containing your invoice data (e.g., client name, email, item details, amounts).
• Invoice Ninja Account: An Invoice Ninja account with API access enabled.
• Gmail Account: A Gmail account for sending emails.
• Google Sheets Credentials: Configured Google Sheets OAuth2 credentials in n8n.
• Invoice Ninja API Key: An API key for your Invoice Ninja account.
• Gmail Credentials: Configured Gmail OAuth2 credentials in n8n.

Setup/Usage

1. Import the Workflow:
   • Copy the provided JSON code.
   • In your n8n instance, go to "Workflows" and click "New".
   • Click the "Import from JSON" button and paste the workflow JSON.
2. Configure Credentials:
   • Google Sheets Trigger:
     • Click on the "Google Sheets Trigger" node.
     • Select or create a new "Google Sheets" credential (OAuth2).
     • Specify the "Spreadsheet ID" and "Sheet Name" that the workflow should monitor.
   • HTTP Request (Invoice Ninja):
     • Click on the "HTTP Request" node.
     • Configure the HTTP Request to interact with your Invoice Ninja API. You will need to set the method (likely POST), the URL for creating invoices, and include your Invoice Ninja API key in the headers (e.g., X-API-TOKEN).
     • Map the data from the "Google Sheets Trigger" node to the body of the HTTP request to create the invoice (e.g., client email, item descriptions, quantities, prices).
   • Gmail:
     • Click on the "Gmail" node.
     • Select or create a new "Gmail" credential (OAuth2).
     • Configure the "To" field to use the client's email address from the Google Sheet data.
     • Set the "Subject" and "Body" of the email. You can include dynamic data from the Invoice Ninja response (e.g., invoice number, a link to the invoice PDF). You might need to add an attachment if Invoice Ninja provides a direct PDF link or generate one.
3. Activate the Workflow:
   • Once all credentials and node settings are configured, click the "Activate" toggle in the top right corner of the n8n editor to enable the workflow.

Now, whenever a new row is added or an existing row is updated in your specified Google Sheet, this workflow will automatically create an invoice in Invoice Ninja and send it to the client via Gmail.