Hello, I'm trying to add a new data source to my Galaxy instance, using synchronous data depositing. The data source needs to know the email address of the user who tries to import data to the Galaxy server. I would have like to write something like that: <inputs action="https://example.com/my/data/source" check_values="false" method="get"> <display>Browse the XX data source $GALAXY_URL</display> <param name="user_email" type="hidden" value="$__user_email__" /> </inputs> Then Galaxy would have generated this url: https://example.com/my/data/source?GALAXY_URL=http....&user_email=test@example.com But this doesn't work, because the $__user_email__ seems to be available only in <command> tag. I end up with this url which is useless: https://example.com/my/data/source?GALAXY_URL=http....&user_email=$__user_email__ Is there any way to do what I need to do? It would be great if variables were available in <param> tags too. Otherwise, maybe I could write a custom tool type to do this. Is there any guideline for this? I have seen someone talking about that a few months ago, but with no answer: http://lists.bx.psu.edu/pipermail/galaxy-dev/2012-September/011258.html Thanks for your help Regards Anthony Bretaudeau