diff --git a/examples/sph/run_sph_rendering.py b/examples/sph/run_sph_rendering.py
index ee4439568..78235f472 100644
--- a/examples/sph/run_sph_rendering.py
+++ b/examples/sph/run_sph_rendering.py
@@ -211,7 +211,16 @@ def H_profile(r):
 setup.apply_setup(gen_disc)
 
 model.do_vtk_dump("init_disc.vtk", True)
+model.dump("tmp.sham")
 
+
+ctx = shamrock.Context()
+model = shamrock.get_Model_SPH(context=ctx, vector_type="f64_3", sph_kernel="M4")
+model.load_from_dump("tmp.sham")
+
+model.dump("tmp2.sham")
+
+exit()
 model.change_htolerances(coarse=1.3, fine=1.1)
 model.timestep()
 model.change_htolerances(coarse=1.1, fine=1.1)
diff --git a/src/shammodels/sph/src/Model.cpp b/src/shammodels/sph/src/Model.cpp
index d05168906..204599769 100644
--- a/src/shammodels/sph/src/Model.cpp
+++ b/src/shammodels/sph/src/Model.cpp
@@ -32,6 +32,7 @@
 #include "shamrock/patch/PatchDataLayer.hpp"
 #include "shamrock/scheduler/DataInserterUtility.hpp"
 #include "shamrock/scheduler/PatchScheduler.hpp"
+#include "shamrock/solvergraph/ScalarEdgeSerializable.hpp"
 #include "shamsys/NodeInstance.hpp"
 #include "shamsys/legacy/log.hpp"
 #include <functional>
@@ -69,6 +70,10 @@ void shammodels::sph::Model<Tvec, SPHKernel>::init() {
 
     PatchScheduler &sched = shambase::get_check_ref(ctx.sched);
 
+    auto time_edge = sched.synchronized_data.container.register_edge(
+        "time", shamrock::solvergraph::ScalarEdgeSerializable<Tscal>("time", "t"));
+    time_edge->value = 0;
+
     sched.add_root_patch();
 
     shamlog_debug_ln("Sys", "build local scheduler tables");
diff --git a/src/shamrock/include/shamrock/scheduler/PatchScheduler.hpp b/src/shamrock/include/shamrock/scheduler/PatchScheduler.hpp
index 602504e69..034d210eb 100644
--- a/src/shamrock/include/shamrock/scheduler/PatchScheduler.hpp
+++ b/src/shamrock/include/shamrock/scheduler/PatchScheduler.hpp
@@ -23,15 +23,19 @@
 #include "shambase/DistributedData.hpp"
 #include "shambase/stacktrace.hpp"
 #include "shambase/time.hpp"
+#include "nlohmann/json_fwd.hpp"
 #include "shamalgs/collective/distributedDataComm.hpp"
 #include "shamrock/legacy/patch/utility/patch_field.hpp"
 #include "shamrock/solvergraph/NodeSetEdge.hpp"
 #include "shamrock/solvergraph/PatchDataLayerRefs.hpp"
+#include "shamrock/solvergraph/SolverGraph.hpp"
 #include <nlohmann/json.hpp>
+#include <unordered_map>
 #include <unordered_set>
 #include <fstream>
 #include <functional>
 #include <memory>
+#include <optional>
 #include <stdexcept>
 #include <tuple>
 #include <vector>
@@ -47,8 +51,25 @@
 #include "shamrock/scheduler/HilbertLoadBalance.hpp"
 #include "shamrock/scheduler/PatchTree.hpp"
 #include "shamrock/scheduler/SchedulerPatchData.hpp"
+#include "shamrock/solvergraph/IEdgeNamed.hpp"
+#include "shamrock/solvergraph/JsonSerializable.hpp"
 #include "shamsys/legacy/sycl_handler.hpp"
 
+inline std::unordered_map<
+    std::string,
+    std::function<std::shared_ptr<shamrock::solvergraph::IEdge>(const nlohmann::json &j)>>
+    deser_map = {};
+
+/// Data stored within the scheduler that are garanteed to be in sink across all ranks
+struct SynchronizedData {
+    shamrock::solvergraph::SolverGraph container
+        = shamrock::solvergraph::SolverGraph::with_constraint(
+            std::nullopt, shamrock::solvergraph::json_serializable_edge_constraint);
+
+    nlohmann::json to_json();
+
+    void from_json(const nlohmann::json &j);
+};
 struct PatchSchedulerConfig {
     u64 split_load_value = 0_u64;
     u64 merge_load_value = 0_u64;
@@ -98,9 +119,10 @@ class PatchScheduler {
     u64 crit_patch_split; ///< splitting limit (if load value > crit_patch_split => patch split)
     u64 crit_patch_merge; ///< merging limit (if load value < crit_patch_merge => patch merge)
 
-    SchedulerPatchList patch_list; ///< handle the list of the patches of the scheduler
-    SchedulerPatchData patch_data; ///< handle the data of the patches of the scheduler
-    PatchTree patch_tree;          ///< handle the tree structure of the patches
+    SchedulerPatchList patch_list;      ///< handle the list of the patches of the scheduler
+    SchedulerPatchData patch_data;      ///< handle the data of the patches of the scheduler
+    PatchTree patch_tree;               ///< handle the tree structure of the patches
+    SynchronizedData synchronized_data; ///< data that is synchroneous across all ranks
 
     // using unordered set is not an issue since we use the find command after
     std::unordered_set<u64> owned_patch_id; ///< list of owned patch ids updated with
diff --git a/src/shamrock/include/shamrock/solvergraph/IEdgeNamed.hpp b/src/shamrock/include/shamrock/solvergraph/IEdgeNamed.hpp
index 17ac3a062..d0a0c1269 100644
--- a/src/shamrock/include/shamrock/solvergraph/IEdgeNamed.hpp
+++ b/src/shamrock/include/shamrock/solvergraph/IEdgeNamed.hpp
@@ -29,6 +29,7 @@ namespace shamrock::solvergraph {
 
         virtual std::string _impl_get_dot_label() const { return name; }
         virtual std::string _impl_get_tex_symbol() const { return "{" + texsymbol + "}"; }
+        virtual std::string get_raw_tex_symbol() const { return texsymbol; }
     };
 
 } // namespace shamrock::solvergraph
diff --git a/src/shamrock/include/shamrock/solvergraph/JsonSerializable.hpp b/src/shamrock/include/shamrock/solvergraph/JsonSerializable.hpp
new file mode 100644
index 000000000..602a3924a
--- /dev/null
+++ b/src/shamrock/include/shamrock/solvergraph/JsonSerializable.hpp
@@ -0,0 +1,38 @@
+// -------------------------------------------------------//
+//
+// SHAMROCK code for hydrodynamics
+// Copyright (c) 2021-2026 Timothée David--Cléris <tim.shamrock@proton.me>
+// SPDX-License-Identifier: CeCILL Free Software License Agreement v2.1
+// Shamrock is licensed under the CeCILL 2.1 License, see LICENSE for more information
+//
+// -------------------------------------------------------//
+
+#pragma once
+
+/**
+ * @file JsonSerializable.hpp
+ * @author Timothée David--Cléris (tim.shamrock@proton.me)
+ * @brief
+ */
+
+#include "shamrock/solvergraph/IEdge.hpp"
+#include <nlohmann/json.hpp>
+#include <string>
+
+namespace shamrock::solvergraph {
+
+    struct JsonSerializable {
+        virtual ~JsonSerializable() {};
+
+        virtual void to_json(nlohmann::json &j)         = 0;
+        virtual void from_json(const nlohmann::json &j) = 0;
+
+        virtual std::string type_name() = 0;
+    };
+
+    inline bool json_serializable_edge_constraint(
+        const std::shared_ptr<shamrock::solvergraph::IEdge> &edge) {
+        // check that the edge can be cross-casted to JsonSerializable
+        return bool(std::dynamic_pointer_cast<JsonSerializable>(edge));
+    };
+} // namespace shamrock::solvergraph
diff --git a/src/shamrock/include/shamrock/solvergraph/ScalarEdgeSerializable.hpp b/src/shamrock/include/shamrock/solvergraph/ScalarEdgeSerializable.hpp
new file mode 100644
index 000000000..57f7c487f
--- /dev/null
+++ b/src/shamrock/include/shamrock/solvergraph/ScalarEdgeSerializable.hpp
@@ -0,0 +1,85 @@
+// -------------------------------------------------------//
+//
+// SHAMROCK code for hydrodynamics
+// Copyright (c) 2021-2026 Timothée David--Cléris <tim.shamrock@proton.me>
+// SPDX-License-Identifier: CeCILL Free Software License Agreement v2.1
+// Shamrock is licensed under the CeCILL 2.1 License, see LICENSE for more information
+//
+// -------------------------------------------------------//
+
+#pragma once
+
+/**
+ * @file ScalarEdgeSerializable.hpp
+ * @author Timothée David--Cléris (tim.shamrock@proton.me)
+ * @brief
+ *
+ */
+
+#include "shambase/exception.hpp"
+#include "shambase/pre_main_call.hpp"
+#include "shambase/string.hpp"
+#include "shambase/type_name_info.hpp"
+#include "nlohmann/json_fwd.hpp"
+#include "shamrock/scheduler/PatchScheduler.hpp"
+#include "shamrock/solvergraph/IEdge.hpp"
+#include "shamrock/solvergraph/ScalarEdge.hpp"
+#include <memory>
+#include <stdexcept>
+
+namespace shamrock::solvergraph {
+
+    template<class T>
+    class ScalarEdgeSerializable : public ScalarEdge<T>, public JsonSerializable {
+        public:
+        using ScalarEdge<T>::ScalarEdge;
+        using ScalarEdge<T>::value;
+
+        virtual void to_json(nlohmann::json &j) {
+            j = nlohmann::json{
+                {"type", type_name()},
+                {"value", value},
+                {"label", this->get_label()},
+                {"tex_symbol", this->get_raw_tex_symbol()}};
+        };
+
+        virtual void from_json(const nlohmann::json &j) {
+            std::string type = j.at("type");
+
+            if (type != type_name()) {
+                throw shambase::make_except_with_loc<std::runtime_error>(shambase::format(
+                    "error when deserializing ScalarEdgeSerializable, expected type info "
+                    "\"{}\" but got \"{}\"",
+                    type_name(),
+                    type));
+            }
+
+            value = j.at("value").get<T>();
+        };
+
+        inline static std::string type_name_static() {
+            return "ScalarEdgeSerializable<" + shambase::get_type_name<T>() + ">";
+        }
+
+        virtual std::string type_name() { return type_name_static(); };
+    };
+
+} // namespace shamrock::solvergraph
+
+template<class T>
+void register_ctor_deser() {
+
+    auto ctor = [](const nlohmann::json &j) -> std::shared_ptr<shamrock::solvergraph::IEdge> {
+        std::string label      = j.at("label").get<std::string>();
+        std::string tex_symbol = j.at("tex_symbol").get<std::string>();
+
+        return std::make_shared<shamrock::solvergraph::ScalarEdgeSerializable<T>>(
+            label, tex_symbol);
+    };
+
+    deser_map.insert({shamrock::solvergraph::ScalarEdgeSerializable<T>::type_name_static(), ctor});
+}
+
+PRE_MAIN_FUNCTION_CALL([&]() {
+    register_ctor_deser<f64>();
+})
diff --git a/src/shamrock/include/shamrock/solvergraph/SolverGraph.hpp b/src/shamrock/include/shamrock/solvergraph/SolverGraph.hpp
index 6f4006afa..cd744f06b 100644
--- a/src/shamrock/include/shamrock/solvergraph/SolverGraph.hpp
+++ b/src/shamrock/include/shamrock/solvergraph/SolverGraph.hpp
@@ -16,14 +16,40 @@
  *
  */
 
+#include "shambase/exception.hpp"
 #include "shambase/memory.hpp"
 #include "shamrock/solvergraph/IEdge.hpp"
 #include "shamrock/solvergraph/INode.hpp"
 #include <unordered_map>
+#include <functional>
 #include <memory>
+#include <optional>
+#include <stdexcept>
+#include <vector>
 
 namespace shamrock::solvergraph {
 
+    struct SolverGraphContraint {
+        std::optional<std::function<bool(const std::shared_ptr<INode> &)>> _validate_node;
+        std::optional<std::function<bool(const std::shared_ptr<IEdge> &)>> _validate_edge;
+
+        inline static SolverGraphContraint no_constraint() { return {std::nullopt, std::nullopt}; }
+
+        inline bool validate_node(const std::shared_ptr<INode> &node) {
+            if (_validate_node) {
+                return (*_validate_node)(node);
+            }
+            return true;
+        }
+
+        inline bool validate_edge(const std::shared_ptr<IEdge> &edge) {
+            if (_validate_edge) {
+                return (*_validate_edge)(edge);
+            }
+            return true;
+        }
+    };
+
     /**
      * @brief A graph container for managing solver nodes and edges with type-safe access.
      *
@@ -55,16 +81,31 @@ namespace shamrock::solvergraph {
      */
     class SolverGraph {
         /// Registry of nodes by name
-        std::unordered_map<std::string, std::shared_ptr<INode>> nodes;
+        std::unordered_map<std::string, std::shared_ptr<INode>> nodes = {};
 
         /// Registry of edges by name
-        std::unordered_map<std::string, std::shared_ptr<IEdge>> edges;
+        std::unordered_map<std::string, std::shared_ptr<IEdge>> edges = {};
+
+        SolverGraphContraint constraint = SolverGraphContraint::no_constraint();
 
         public:
         ///////////////////////////////////////
         // base getters and setters
         ///////////////////////////////////////
 
+        SolverGraph() = default;
+
+        SolverGraph(
+            std::optional<std::function<bool(const std::shared_ptr<INode> &)>> _validate_node,
+            std::optional<std::function<bool(const std::shared_ptr<IEdge> &)>> _validate_edge)
+            : constraint(SolverGraphContraint{_validate_node, _validate_edge}) {}
+
+        inline static SolverGraph with_constraint(
+            std::optional<std::function<bool(const std::shared_ptr<INode> &)>> _validate_node,
+            std::optional<std::function<bool(const std::shared_ptr<IEdge> &)>> _validate_edge) {
+            return SolverGraph{_validate_node, _validate_edge};
+        }
+
         /**
          * @brief Register a node with the graph using a shared pointer.
          *
@@ -74,6 +115,12 @@ namespace shamrock::solvergraph {
          */
         inline std::shared_ptr<INode> register_node_ptr_base(
             const std::string &name, std::shared_ptr<INode> node) {
+
+            if (!constraint.validate_node(node)) {
+                throw shambase::make_except_with_loc<std::invalid_argument>(
+                    "node validation failed under solvergraph constraint");
+            }
+
             const auto [it, inserted] = nodes.try_emplace(name, std::move(node));
             if (!inserted) {
                 shambase::throw_with_loc<std::invalid_argument>(
@@ -91,6 +138,12 @@ namespace shamrock::solvergraph {
          */
         inline std::shared_ptr<IEdge> register_edge_ptr_base(
             const std::string &name, std::shared_ptr<IEdge> edge) {
+
+            if (!constraint.validate_edge(edge)) {
+                throw shambase::make_except_with_loc<std::invalid_argument>(
+                    "edge validation failed under solvergraph constraint");
+            }
+
             const auto [it, inserted] = edges.try_emplace(name, std::move(edge));
             if (!inserted) {
                 shambase::throw_with_loc<std::invalid_argument>(
@@ -336,6 +389,24 @@ namespace shamrock::solvergraph {
         inline const T &get_edge_ref(const std::string &name) const {
             return shambase::get_check_ref(get_edge_ptr<T>(name));
         }
+
+        std::vector<std::string> get_edge_names() {
+            std::vector<std::string> ret{};
+
+            for (auto &[k, e] : edges) {
+                ret.push_back(k);
+            }
+            return ret;
+        }
+
+        std::vector<std::string> get_node_names() {
+            std::vector<std::string> ret{};
+
+            for (auto &[k, n] : nodes) {
+                ret.push_back(k);
+            }
+            return ret;
+        }
     };
 
 } // namespace shamrock::solvergraph
diff --git a/src/shamrock/src/io/ShamrockDump.cpp b/src/shamrock/src/io/ShamrockDump.cpp
index e3e7c97e8..e66ffa2fd 100644
--- a/src/shamrock/src/io/ShamrockDump.cpp
+++ b/src/shamrock/src/io/ShamrockDump.cpp
@@ -200,6 +200,9 @@ namespace shamrock {
         sched.patch_list = jmeta_patch.at("patchlist").get<SchedulerPatchList>();
         sched.patch_tree = jmeta_patch.at("patchtree").get<scheduler::PatchTree>();
         sched.patch_data.sim_box.from_json(jmeta_patch.at("sim_box"));
+        if (jmeta_patch.contains("synchronized_data")) {
+            sched.synchronized_data.from_json(jmeta_patch.at("synchronized_data"));
+        }
 
         // edit patch owner to fit in new world size, or spread if more processes now
         // a bit dirty but gets the job done for now
diff --git a/src/shamrock/src/scheduler/PatchScheduler.cpp b/src/shamrock/src/scheduler/PatchScheduler.cpp
index 9faace65f..901cf24df 100644
--- a/src/shamrock/src/scheduler/PatchScheduler.cpp
+++ b/src/shamrock/src/scheduler/PatchScheduler.cpp
@@ -18,6 +18,7 @@
 #include "shambase/stacktrace.hpp"
 #include "shambase/string.hpp"
 #include "shambase/time.hpp"
+#include "nlohmann/json_fwd.hpp"
 #include "shambackends/math.hpp"
 #include "shambackends/typeAliasVec.hpp"
 #include "shamrock/legacy/patch/base/patchdata.hpp"
@@ -212,8 +213,8 @@ PatchScheduler::PatchScheduler(
     u64 crit_merge)
     : pdl_ptr(pdl_ptr),
       patch_data(
-          pdl_ptr,
-          {{0, 0, 0}, {max_axis_patch_coord, max_axis_patch_coord, max_axis_patch_coord}}) {
+          pdl_ptr, {{0, 0, 0}, {max_axis_patch_coord, max_axis_patch_coord, max_axis_patch_coord}}),
+      synchronized_data() {
 
     crit_patch_split = crit_split;
     crit_patch_merge = crit_merge;
@@ -1021,11 +1022,36 @@ nlohmann::json PatchScheduler::serialize_patch_metadata() {
     nlohmann::json jsim_box;
     patch_data.sim_box.to_json(jsim_box);
 
+    nlohmann::json jsynchro_data = synchronized_data.to_json();
+
     return {
         {"patchtree", patch_tree},
         {"patchlist", patch_list},
         {"patchdata_layout", pdl_old()},
         {"sim_box", jsim_box},
         {"crit_patch_split", crit_patch_split},
-        {"crit_patch_merge", crit_patch_merge}};
+        {"crit_patch_merge", crit_patch_merge},
+        {"synchronized_data", jsynchro_data}};
+}
+
+nlohmann::json SynchronizedData::to_json() {
+
+    nlohmann::json edges{};
+
+    using namespace shamrock::solvergraph;
+
+    for (const std::string &edgen : container.get_edge_names()) {
+        container.get_edge_ref<JsonSerializable>(edgen).to_json(edges[edgen]);
+    }
+
+    return {{"edges", edges}};
+}
+
+void SynchronizedData::from_json(const nlohmann::json &j) {
+
+    for (auto &el : j.at("edges").items()) {
+        std::string type   = el.value().at("type");
+        auto &deserializer = deser_map.at(type);
+        container.register_edge_ptr_base(el.key(), deserializer(el.value()));
+    }
 }