Invoice Helper

NOTE: The app is in early development. Aimed for using for lithuanian invoices for now.

Invoice Helper is a document extraction helper built on Frappe that semi-automates invoice data extraction from PDFs. It leverages local OCR (Tesseract) and Amazon Textract to extract key invoice fields.

Core Functionality

• Pending Document List: Queue-based workflow for tracking and processing uploaded invoices;
• File upload endpoint (/api/method/invoice_helper_lt.api.upload_pending_document): which can be used to upload documents via API calls;
• File Drawer: UI component to view uploaded document when filling in invoice form
• Document Processing Pipeline: Extracts invoice data using local OCR (Tesseract) and Amazon Textract;
• Party Matching: Automatically finds and links Suppliers/Customers based on Lithuanian tax codes and business IDs;
• Background Task Processing: Handles asynchronous extraction of pending documents;
• Textract Integration: User manually specifies which columns contain barcode, quantity, and price.
• Tabula Support: Local table extraction available for only slightly tilted pages, though not fine-tuned. Requires a Java Runtime Environment (JRE) to be installed on the host.

TODOs / Future Enhancements

• More robust VAT amount extraction
• Doctypes Supplier, Customer needs to have business_code field for party matching to work, so installation needs to create these fields if not present automatically.
• Introduce a re setting, so a user can change the expected tax ID format per country
• Date extraction robustness + compile a test corpus
• Consider bringing in the line extraction OCR, and only suggest the user to use it if the totals completely match.
• Dialog of prefill could be improved to show available options better (as in how many candidates or so)

Installation

You can install this app using the bench CLI:

cd $PATH_TO_YOUR_BENCH
bench get-app https://github.com/martynas2200/invoice-helper-erpnext --branch develop
bench install-app invoice_helper

This app relies on a few system-level tools for PDF/OCR/table processing. Make sure these are installed and available in the PATH of the machine or container running Frappe:

• Poppler utilities (for pdf2image, e.g. pdftoppm)
• Tesseract OCR (for local OCR extraction)
• Optional: Java Runtime Environment / JDK (for tabula-py table extraction)

For example:

• macOS (Homebrew): brew install poppler tesseract openjdk
• Debian/Ubuntu: apt-get update && apt-get install -y poppler-utils tesseract-ocr default-jre-headless

Contributing

This app uses pre-commit for code formatting and linting. Please install pre-commit and enable it for this repository:

cd apps/invoice_helper
pre-commit install

Pre-commit is configured to use the following tools for checking and formatting your code:

• ruff
• eslint
• prettier
• pyupgrade

License

mit