\documentclass{minimal}
\usepackage{logreq}

% biblatex example
% (this is a mockup of code which will be used in biblatex >= 0.9b)

% sample preamble:

% \usepackage[backend=biber]{biblatex}
% \bibliography{bibfile1,bibfile2,bibfile3}

% workflow:

% latex file	(-> both requests active)
% biber file
% latex file	(-> both requests inactive)

% The Biber (> 0.5.3) workflow will be straightforward even if
% there are refsection environments, but additional latex passes
% may be required to resolve labels:

% latex file	(-> both requests active)
% bibtex file
% latex file	(-> latex request active, biber request inactive)
% latex file	(-> both requests inactive)

\logrequest[package=biblatex,priority=5,active=1]{
  \generic{biber}
  \cmdline{
    \binary{biber}
    \infile{\jobname}
  }
  \input{
    \file{\jobname.bcf}
  }
  \output{
    \file{\jobname.bbl}
  }
  \provides[type=dynamic]{
    \file{\jobname.bbl}
  }
  \requires[type=dynamic]{
    \file{\jobname.bcf}
  }
  \requires[type=editable]{
    \let\do=\file
    \docsvlist{bibfile1,bibfile2,bibfile3}
  }
}

\ltxrequest{biblatex}{1}{
  \provides[type=dynamic]{
    \file{\jobname.bcf}
  }
  \requires[type=dynamic]{
    \file{\jobname.bbl}
  }
  \requires[type=static]{
    \let\do=\file
    \docsvlist{biblatex.def,numeric.bbx,standard.bbx,numeric.cbx,
               biblatex.cfg,american.lbx,english.lbx}
  }
}

\begin{document}
\end{document}