\usemodule[tikz]

\starttext

\startbuffer[tikz-picture]
  \starttikzpicture
    \fill[red] (0,0) circle (2);
  \stoptikzpicture
\stopbuffer

\placefigure{A tikz figure}{\getbuffer[tikz-picture]}

\placefigure{Another tikz figure}{
  \starttikzpicture
    \fill[red] (0,0) circle (2);
  \stoptikzpicture
}

\placefigure{An external tikz figure}{
  \externalfigure[tikzfig.pdf]
}

\stoptext
