Hi,
For my book, the header for each chapter should be like the attached image. I don't know if I am using the best method, but the result looks like what I want. Nevertheless, I am having some problems :
1. the header appears on each page ;
2. the title of the chapter should not appear in the body of the text.
Thanks for your help.
Fabrice

\definecolor[MyColorA][r=0.8784, g=0.8784, b=0.8784]
\defineframedtext
          [FramedText]
          [
            offset=0.6em,
            style=,
            toffset=\lineheight,
            background=color,
            backgroundcolor=MyColorA,
            foregroundstyle={\switchtobodyfont[11pt]},
            align={left, broad},
            frame=off,
            width=\textwidth,
          ]


\setuplabeltext
     [en]
     [chapter=CHAPITRE]

\setuphead
   [chapter]
   [bodypartlabel=]


\startsetups [header]
     \labeltext{chapter} \getmarking[chapternumber]
\stopsetups
   
\setupheadertexts
  []
  [{\FramedText{{\cap\labeltext{chapter}\space\getmarking[chapternumber]}
     \\
    \bfc\getmarking[chapter]}}]
  []
  [\FramedText{{\cap\labeltext{chapter}\space \getmarking[chapternumber]}
     \\
   \bfc\getmarking[chapter]}]


\setuppagenumbering
     [alternative=doublesided,location=]
\starttext
\startchapter [title=La récurrence]
  \startsection[title={Le principe de récurrence}]
     \dorecurse{10}{\input knuth}
  \stopsection
  \startsection[title={Le raisonement par récurrence}]
      \dorecurse{10}{\input knuth}
  \stopsection
  \startsection[title={Récurrences fortes}]
      \dorecurse{10}{\input knuth}
  \stopsection
   \startsection[title={Exercices corrigés}]
      \dorecurse{10}{\input knuth}
  \stopsection  
\stopchapter
\startchapter [title=Combinatoire-Dénombrement]
    \dorecurse{10}{\input knuth}
\stopchapter  

\stoptext
pied_3.png