Middleware is an important part of many search engine web crawling processes. We developed a middleware, the Crawl Document Importer (CDI), which selectively imports documents and the associated metadata to the digital library CiteSeerX crawl repository and database. This middleware is designed to be extensible as it provides a universal interface to the crawl database. It is designed to support input from multiple open source crawlers and archival formats, e.g., ARC, WARC. It can also import files downloaded via FTP. To use this middleware for another crawler, the user only needs to write a new log parser which returns a resource object with the standard metadata attributes and tells the middleware how to access downloaded files. When importing documents, users can specify document mime types and obtain text extracted from PDF/postscript documents. The middleware can adaptively identify academic research papers based on document context features. We developed a web user interface where the user can submit importing jobs. The middleware package can also work on supplemental jobs related to the crawl database and respository. Though designed for the CiteSeerX search engine, we feel this design would be appropriate for many search engine web crawling systems.