\usemodule[filter]

\defineexternalfilter
  [pandoc]
  [filtercommand={pandoc -f \externalfilterparameter{format} -t context 
                  -i \externalfilterinputfile\space
                  -o \externalfilteroutputfile},
   format=markdown,
   directory=output]        
   
   \traceexternalfilters
   
   
\setupbodyfont[14pt]

\starttext   
   
   \processpandocfile{test3.text}
   
\stoptext