Extract & Classify Invoices & Receipts with Gmail, OpenAI and Google Drive

Who is it for?

Anyone who wants to automatically aggregate their invoices or receipts. Main beneficiaries: small business owners and freelancers.

How it works

1. Creates a folder in Google Drive for uploading invoices and receipts. Responds (Webhook response) with URL to the created folder.
2. Gets all emails with attachments from a Gmail mailbox.
3. (Optional) Filters emails, e.g. exclude emails sent to specific address.
4. Filters only PDF attachments.
5. Classifies all PDF attachment contents with an AI model (is it a receipt or an invoice?).
6. Uploads receipts and invoices to the created Google Drive folder and optionally sends an email with the attachments to, e.g., your accountant.

Pre-conditions/Requirements

• Gmail and Google Drive accounts
• A Google Cloud OAuth 2.0 Client ID or a service account with Google Drive and Gmail APIs enabled
• OpenAI API account and API key

Set up steps

1. Provide credentials for the nodes: Gmail, Google Drive, OpenAI.
2. Configure parameters in the "Configure" node. Most importantly:
   • "sendInvoicesTo" for the email address where invoices/receipts should be sent.
3. It uses a Webhook node trigger. It expects a body with a schema such as:

{
  "name": "getInvoicesAndReceiptsFromEmails",
  "description": "Finds and uploads to Google Drive all receipts and invoices from emails within a specified date range.",
  "parameters": {
    "type": "object",
    "properties": {
      "startDate": {
        "type": "string",
        "format": "date-time",
        "description": "The start date of the range to search for emails. Must be in ISO 8601 format."
      },
      "endDate": {
        "type": "string",
        "format": "date-time",
        "description": "The end date of the range to search for emails. Must be in ISO 8601 format."
      },
      "sendEmail": {
        "type": "boolean",
        "description": "Indicates whether to send an email with all receipts and invoices after processing. Must be true or false."
      }
    },
    "required": [
      "startDate",
      "endDate"
    ]
  }
}

Example body:

{
  "startDate": "2025-03-01T00:00:00Z",
  "endDate": "2025-04-01T00:00:00Z",
  "sendEmail": true
}

How to use with AI chat

You can trigger the workflow with an AI chat that supports tool use, such as BrowseWiz. For setup instructions, read the blog post.