diff --git a/doc/environments/fancythm/fancythm.dtx b/doc/environments/fancythm/fancythm.dtx
index 9dd032c..2f80f74 100644
--- a/doc/environments/fancythm/fancythm.dtx
+++ b/doc/environments/fancythm/fancythm.dtx
@@ -55,6 +55,8 @@
 %  \subsection{Dependencies}
 %    \begin{macrocode}
 \RequirePackage{l3keys2e}
+\RequirePackage{groupthm}
+\RequirePackage[default styles]{mkessler-thmstyle}
 %    \end{macrocode}
 %
 %  \subsection{Counter management}
@@ -299,11 +301,53 @@
 %    \end{macrocode}
 % \end{variable}
 % 
+% 
+% 
+% 
+% \begin{variable}
+%   {
+%     \l_@@_key_name_tl,
+%     \l_@@_key_mdframed_tl,
+%     \l_@@_key_style_tl,
+%     \l_@@_key_group_clist,
+%     \l_@@_key_thmtools_clist,
+%   }
+%     
+%
+%    \begin{macrocode}
+\tl_new:N    \l_@@_key_name_tl
+\tl_new:N    \l_@@_key_mdframed_tl
+\tl_new:N    \l_@@_key_style_tl
+\clist_new:N \l_@@_key_group_clist
+\clist_new:N \l_@@_key_thmtools_clist
+%    \end{macrocode}
+% \end{variable}
+% 
+% 
+%
+% \begin{variable}
+%   {
+%     \l_@@_name_tl,
+%     \l_@@_thmtools_clist,
+%     \l_@@_group_clist,
+%   }
+%     
+%
+%    \begin{macrocode}
+\tl_new:N    \l_@@_name_tl
+\clist_new:N \l_@@_thmtools_clist
+\clist_new:N \l_@@_group_clist
+%    \end{macrocode}
+% \end{variable}
+% 
 %    \subsection{Key interface}
 % 
+% \begin{texnote}
 %  Note that unfortunately, none of the keynames really containes a space.
 %  \LaTeX2e strips spaces before loading a package, so introducing them here
 %  would make them inaccessible.
+%  Here they are ignored by \LaTeX3 and are present for readability.
+% \end{texnote}
 %
 %
 %    \begin{macrocode}
@@ -329,13 +373,35 @@
 %    \end{macrocode}
 % 
 % 
-%  Process the given keys:
 %
 %
+% 
+%
+%    \begin{macrocode}
+\keys_define:nn { fancythm / fancytheorem } 
+  {
+    name            .tl_set:N      = \l_@@_key_name_tl           ,
+    name            .default:n     = \c_novalue_tl               ,
+    mdframed        .tl_set:N      = \l_@@_key_mdframed_tl       ,
+    mdframed        .default:n     = \c_novalue_tl               ,
+    style           .tl_set:N      = \l_@@_key_style_tl          ,
+    style           .default:n     = \c_novalue_tl               ,
+    group           .clist_set:N   = \l_@@_key_group_clist       ,
+    group           .default:n     = {}                          ,
+    thmtools        .clist_set:N   = \l_@@_key_thmtools_clist    ,
+    thmtools        .default:n     = {}                          ,
+  }
+%    \end{macrocode}
+% 
+% 
+%    Process the given keys:
+%
 %    \begin{macrocode}
 \ProcessKeysOptions{ fancythm }
 %    \end{macrocode}
-%
+% 
+% 
+% 
 % 
 %    This sets up translation if requested.
 %    Throughout implementation, we can just use \cs{@@_translate:n}
@@ -352,6 +418,124 @@
     \cs_set_eq:NN \@@_translate:n \use:n
   }
 %    \end{macrocode}
+%
+% 
+% 
+%
+% \begin{macro}{\@@_set_normalized_keys:nn}
+%   
+%   \begin{syntax}
+%     \cs{@@_set_normalized_keys:nn}\marg{keys}\marg{fallback name}
+%   \end{syntax}
+%     
+%
+%    \begin{macrocode}
+\cs_new:Npn \@@_set_normalized_keys:nn #1 #2
+  {
+    \keys_set:nn { fancythm / fancytheorem } { name, mdframed, style, group, thmtools }
+    \keys_set:nn { fancythm / fancytheorem } { #1 }
+    \clist_set_eq:NN \l_@@_group_clist \l_@@_key_group_clist
+    \clist_set_eq:NN \l_@@_thmtools_clist \l_@@_key_thmtools_clist
+    \tl_if_eq:NnF \l_@@_key_mdframed_tl { \c_novalue_tl }
+      {
+        \clist_put_right:Nx \l_@@_thmtools_clist
+          {
+            mdframed = \tl_use:N \l_@@_key_mdframed_tl
+          }
+      }
+    \tl_if_eq:NnF \l_@@_key_style_tl { \c_novalue_tl }
+      {
+        \clist_put_right:Nx \l_@@_thmtools_clist
+          {
+            style = \tl_use:N \l_@@_key_style_tl
+          }
+      }
+    \tl_if_eq:NnTF \l_@@_key_name_tl { \c_novalue_tl }
+      {
+        \tl_set:Nx \l_@@_name_tl
+        {
+          \text_titlecase_first:n { \tl_trim_spaces:n { #2 } }
+        }
+      }
+      {
+        \tl_set_eq:NN \l_@@_name_tl \l_@@_key_name_tl
+      }
+  }
+%    \end{macrocode}
+% \end{macro}
+% 
+% 
+% 
+%
+% \begin{macro}{\fancythm_new_theorem:nnnn}
+%    \begin{syntax}
+%       \cs{fancythm_new_theorem:nnnn}\marg{fancy theorem}\marg{groups}
+%       \marg{name}\marg{thmtools keys}
+%    \end{syntax}
+%		 
+%     
+%
+%    \begin{macrocode}
+\cs_new:Npn \fancythm_new_theorem:nnnn #1 #2 #3 #4
+  {
+    \groupthm_new_family:nnnnn { #1 } { dagger, star } { #3 } { #4 } { #2 }
+    \groupthm_new_family_options:nnnn
+      { #1 }
+      { !s !t+ }
+      {
+        \IfBooleanT { ##1 } 
+          {
+            \groupthm_add_theorem_to_group:n { star }
+          }
+        \IfBooleanT { ##2 }
+          {
+            \groupthm_add_theorem_to_group:n { dagger }
+          }
+      }
+      { #2 }
+  }
+\cs_generate_variant:Nn \fancythm_new_theorem:nnnn { n V V V }
+%    \end{macrocode}
+% \end{macro}
+%
+% 
+%
+% \begin{macro}{\fancythm_new_theorem:nn}
+%    \begin{syntax}
+%       \cs{fanythm_new_theorem:nn}\marg{key=value list}\marg{fancy theorem}
+%    \end{syntax}
+%		 
+%     
+%
+%    \begin{macrocode}
+\cs_new:Npn \fancythm_new_theorem:nn #1 #2
+  {
+    \@@_set_normalized_keys:nn { #1 } { #2 }
+    \fancythm_new_theorem:nVVV
+      { #2 }
+      \l_@@_group_clist
+      \l_@@_name_tl
+      \l_@@_thmtools_clist
+  }
+%    \end{macrocode}
+% \end{macro}
+% 
+% 
+%
+% \begin{macro}{\NewFancyTheorem}
+%    \begin{syntax}
+%       \cs{NewFancyTheorem}\marg{key=value list}\marg{fancy theorem}
+%    \end{syntax}
+%		 
+%     
+%
+%    \begin{macrocode}
+\NewDocumentCommand { \NewFancyTheorem } { O{} m }
+  {
+    \fancythm_new_theorem:nn { #1 } { #2 }
+  }
+%    \end{macrocode}
+% \end{macro}
 % 
 %    \begin{macrocode}
 %