Hi @jackleland So, when you do a stream access you cannot have a whole file pre-computed checksum. I mean you can do it at source (where you can see the whole file), but streaming is just remote access on range of bytes.. there is no concept to pass a whole file pre-computed checksum when the access no only that read only some ranges of bytes, but the ranges can also be non contiguous (like reading only some branches on a TTree, so only a certain baskets are actually transferred). Also when streaming, there is no data written at destination, so again you cannot have the concept of having a checksum at destination. I apologize if i'm being redundant or not getting what you try to do.. As for documentation, as in many cases, the best documentation is the source :) https://github.com/xrootd/xrootd/blob/master/bindings/python/libs/client/file.py#L30 https://github.com/xrootd/xrootd/blob/master/bindings/python/src/PyXRootDFile.hh https://github.com/xrootd/xrootd/blob/master/src/XrdCl/XrdClFile.hh -- Reply to this email directly or view it on GitHub: https://github.com/xrootd/xrootd/issues/2071#issuecomment-1684385076 You are receiving this because you are subscribed to this thread. Message ID: <[log in to unmask]> ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the XROOTD-DEV list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-DEV&A=1