A developer launched a Haskell command-line interface (CLI) to programmatically order groceries via the REWE supermarket chain's API, reverse-engineered from their mobile app. The project, `korb`, allows users to manage shopping lists, search products, and place orders for pickup. The CLI leverages REWE's mTLS authentication and generates OpenAPI specifications automatically. The developer emphasizes the tool's practical use, stating it's designed for agents to organize shopping on behalf of users. Key features include searching products by name or EAN barcode, managing favorites, and a Lean 4-verified suggestion engine ensuring mathematically proven item recommendations.

Installation requires setting up REWE's client certificates and authenticating via a browser flow. The project is explicitly unofficial and carries a 'use at your own risk' disclaimer.