The Domino Web server provides sufficient log data for most situations. Yet, there may be times when you need to capture information about an HTTP request that is not logged by Domino out of the box — cookies coming in and out of the server, for instance. This article teaches developers how to log cookies and other types of requests using undocumented features of the R5 Domino Web Server Application Programming Interface (DSAPI) and the W3C Extended File format. You’ll learn what the DSAPI is, why and when you might use it, and how to write a custom filter for logging HTTP requests in the extensible W3C Extended Log File format, which provides for a wider range of data than can be logged by Domino alone. The HTTP logging filter, including the full source code, is available for free download from THE VIEW’s Web site.