diff --git a/Triangulation_on_hyperbolic_surface_2/doc/Triangulation_on_hyperbolic_surface_2/CGAL/Triangulation_on_hyperbolic_surface_2_IO.h b/Triangulation_on_hyperbolic_surface_2/doc/Triangulation_on_hyperbolic_surface_2/CGAL/Triangulation_on_hyperbolic_surface_2_IO.h
new file mode 100644
index 00000000000..9a6496ce02d
--- /dev/null
+++ b/Triangulation_on_hyperbolic_surface_2/doc/Triangulation_on_hyperbolic_surface_2/CGAL/Triangulation_on_hyperbolic_surface_2_IO.h
@@ -0,0 +1,54 @@
+namespace CGAL{
+
+  /*!
+    \ingroup PkgHyperbolicSurfaceTriangulation2InputOutput
+      inserts the triangulation in a stream.
+      The format of the output is the following.
+      Each dart of the triangulation is given an index between \f$ 0 \f$ and \f$ n-1 \f$, where \f$ n \f$ is the number of darts of the triangulation.
+      The first line contains the number \f$ n \f$ of darts.
+      The next line contains either 'yes' or 'no' and tells whether the triangulation has an anchor.
+      If the triangulation has an anchor, then the four next lines print the index of the dart of the anchor, and the three vertices of the anchor.
+      Then, for every triangle \f$ t \f$, the indices of the three darts of \f$ t \f$ are printed on three distinct lines.
+      Finally, for every edge \f$ e \f$, the indices of the two darts of \f$ e \f$ are printed on two distinct lines, followed by a third line on which the cross ratio of \f$ e \f$ is printed.
+
+      \pre <code>   Triangulation_on_hyperbolic_surface_2<Traits>::is_valid() </code>
+  */
+  std::ostream& operator<<(std::ostream& s, const Triangulation_on_hyperbolic_surface_2<Traits>& triangulation);
+
+  /*!
+    \ingroup PkgHyperbolicSurfaceTriangulation2InputOutput
+      extracts the triangulation from a stream.
+      The format of the input should be the same as the format of the output of
+    the '<<' operator for Triangulation_on_hyperbolic_surface_2.
+ */
+  std::istream& operator>>(std::istream& s, Triangulation_on_hyperbolic_surface_2<Traits>& triangulation);
+
+  /*!
+    \ingroup PkgHyperbolicSurfaceTriangulation2InputOutput
+    inserts the domain in a stream.
+
+      The format of the output is the following.
+      The first line prints the number \f$n\f$ of vertices of the domain.
+      For \f$ i=0 \f$ to \f$ n-1 \f$ the index of the side paired to side \f$ i \f$ is printed on a separate line.
+      For \f$ i=0 \f$ to \f$ n-1 \f$ the i-th vertex is printed on a separate line.
+
+      \pre <code> Hyperbolic_fundamental_domain_2< Traits >::is_valid() </code>
+  */
+  std::ostream& operator<<(std::ostream& s, const Hyperbolic_fundamental_domain_2<Traits>& domain);
+
+   /*!
+    \ingroup PkgHyperbolicSurfaceTriangulation2InputOutput
+    extracts the domain from a stream.
+
+      The format of the input must be the same as the format of the output of
+  the '<<' operator for Hyperbolic_fundamental_domain_2.
+  */
+  std::istream& operator>>(std::istream& s, Hyperbolic_fundamental_domain_2<Traits>& domain);
+
+    /*!
+    \ingroup PkgHyperbolicSurfaceTriangulation2InputOutput
+    inserts the isometry in a stream.
+    */
+    std::ostream& operator<<(std::ostream& s, const Hyperbolic_isometry_2<Traits>& isometry);
+
+}; // namespace CGAL
diff --git a/Triangulation_on_hyperbolic_surface_2/include/CGAL/Triangulation_on_hyperbolic_surface_2_IO.h b/Triangulation_on_hyperbolic_surface_2/include/CGAL/Triangulation_on_hyperbolic_surface_2_IO.h
new file mode 100644
index 00000000000..4a94a06f1f4
--- /dev/null
+++ b/Triangulation_on_hyperbolic_surface_2/include/CGAL/Triangulation_on_hyperbolic_surface_2_IO.h
@@ -0,0 +1,61 @@
+// Copyright (c) 2024
+// INRIA Nancy (France), and Université Gustave Eiffel Marne-la-Vallee (France).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org)
+//
+// $URL$
+// $Id$
+// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
+//
+// Author(s)     : Vincent Despré, Loïc Dubois, Marc Pouget, Monique Teillaud
+
+// This file contains the declaration and the implementation of the input/output
+// functions for the package Triangulation_on_hyperbolic_surface_2
+
+#ifndef CGAL_TRIANGULATION_ON_HYPERBOLIC_SURFACE_2_IO_H
+#define CGAL_TRIANGULATION_ON_HYPERBOLIC_SURFACE_2_IO_H
+
+#include <CGAL/license/Triangulation_on_hyperbolic_surface_2.h>
+#include <CGAL/Triangulation_on_hyperbolic_surface_2.h>
+#include <CGAL/basic.h>
+#include <iostream>
+
+namespace CGAL {
+
+////////////////////////////////////////////////////////////////////////////////
+template<class Traits>
+std::ostream& operator<<(std::ostream& s, const Hyperbolic_fundamental_domain_2<Traits>& domain){
+  CGAL_precondition(domain.is_valid());
+  return domain.to_stream(s);
+}
+
+template<class Traits>
+std::istream& operator>>(std::istream& s, Hyperbolic_fundamental_domain_2<Traits>& domain){
+  return domain.from_stream(s);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+template<class Traits>
+std::ostream& operator<<(std::ostream& s, const Hyperbolic_isometry_2<Traits>& isometry){
+  for (int k=0; k<4; k++){
+    s << isometry.get_coefficient(k);
+  }
+  return s;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+template<class Traits, class Attributes>
+std::ostream& operator<<(std::ostream& s, const Triangulation_on_hyperbolic_surface_2<Traits, Attributes>& triangulation){
+  triangulation.to_stream(s);
+  return s;
+}
+
+template<class Traits, class Attributes>
+void operator>>(std::istream& s, Triangulation_on_hyperbolic_surface_2<Traits, Attributes>& triangulation){
+  triangulation.from_stream(s);
+}
+
+} // namespace CGAL
+
+#endif // CGAL_TRIANGULATION_ON_HYPERBOLIC_SURFACE_2_IO_H