The lister should be based on the assumption that the [[ https://scm.fusionforge.org/anonscm/gitweb?p=fusionforge/fusionforge.git;a=tree;f=src/plugins/repositoryapi;hb=refs/heads/feature/plugin-repositoryapi-6.0 | repository API plugin ]] is enabled on the target forge. (Which, in turn, requires a fusionforge version >= 6.)