go get fossil  Help: /dir

The "/dir" page:

Show the files and subdirectories within a single directory of the
source tree.  Only files for a single check-in are shown if the ci=
query parameter is present.  If ci= is missing, the union of files
across all check-ins is shown.

Query parameters:

   name=PATH        Directory to display.  Optional.  Top-level if missing
   ci=LABEL         Show only files in this check-in.  Optional.
   type=TYPE        TYPE=flat: use this display
                    TYPE=tree: use the /tree display instead