An improved electronic procurement system is disclosed. The electronic procurement system (“system”) implements features such as real-time adaptive extraction of online data. The system is configured to manage a plurality of page types for webpages and for each page type a plurality of field types for fields in webpages. The system is configured to further generate a computer application that can be integrated into a web browser. For each page type, the computer application is programmed to initially generate a signature for each field type based on minimal user interaction with webpages of the page type. The system is configured to also generate an agent using the signature. The agent is programmed to automatically extract data corresponding to the field types from additional webpages of the page type using the signatures. The agent or an associated background process is programmed to also automatically update the signatures when such data extraction is unsuccessful.