diff --git a/.gitmodules b/.gitmodules
index 1045506..8b8595a 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -10,3 +10,6 @@
 [submodule "external/keccak"]
 	path = external/keccak
 	url = https://github.com/gvanas/KeccakCodePackage
+[submodule "external/rapidjson"]
+	path = external/rapidjson
+	url = https://github.com/Tencent/rapidjson
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c663c7a..f437d51 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -65,7 +65,7 @@ configure_file(cmake/version.hpp.in
 file(GLOB_RECURSE PROJECT_SOURCE_FILES ${PROJECT_SOURCE_DIR}/*.cpp)
 
 include_directories("${PROJECT_INCLUDE_DIR}")
-include_directories("external/json/src")
+include_directories("external/rapidjson/include")
 
 ########## DEPENDENCIES ##########
 
diff --git a/external/rapidjson b/external/rapidjson
new file mode 160000
index 0000000..67a17cf
--- /dev/null
+++ b/external/rapidjson
@@ -0,0 +1 @@
+Subproject commit 67a17cfdbc25ff1fc8d01714be87e242b03a4cc9
diff --git a/include/iota/api/requests/add_neighbors.hpp b/include/iota/api/requests/add_neighbors.hpp
index 9cdb948..509f28c 100644
--- a/include/iota/api/requests/add_neighbors.hpp
+++ b/include/iota/api/requests/add_neighbors.hpp
@@ -27,6 +27,8 @@
 
 #include <iota/api/requests/base.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -60,7 +62,7 @@ class AddNeighbors : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/attach_to_tangle.hpp b/include/iota/api/requests/attach_to_tangle.hpp
index e9fb7f0..393797b 100644
--- a/include/iota/api/requests/attach_to_tangle.hpp
+++ b/include/iota/api/requests/attach_to_tangle.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/requests/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -74,7 +76,7 @@ class AttachToTangle : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/base.hpp b/include/iota/api/requests/base.hpp
index 73ffb23..68b745a 100644
--- a/include/iota/api/requests/base.hpp
+++ b/include/iota/api/requests/base.hpp
@@ -25,9 +25,9 @@
 
 #pragma once
 
-#include <json.hpp>
+#include <string>
 
-using json = nlohmann::json;
+#include <iota/utils/json.hpp>
 
 namespace IOTA {
 
@@ -58,7 +58,7 @@ class Base {
    *
    * @param data where to store serialisation.
    */
-  virtual void serialize(json& data) const;
+  virtual void serialize(Utils::json& data) const;
 
 public:
   /**
diff --git a/include/iota/api/requests/broadcast_transactions.hpp b/include/iota/api/requests/broadcast_transactions.hpp
index 9b237d6..3b7a210 100644
--- a/include/iota/api/requests/broadcast_transactions.hpp
+++ b/include/iota/api/requests/broadcast_transactions.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/requests/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -62,7 +64,7 @@ class BroadcastTransactions : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/find_transactions.hpp b/include/iota/api/requests/find_transactions.hpp
index 37ac579..83b67a4 100644
--- a/include/iota/api/requests/find_transactions.hpp
+++ b/include/iota/api/requests/find_transactions.hpp
@@ -73,7 +73,7 @@ class FindTransactions : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/get_balances.hpp b/include/iota/api/requests/get_balances.hpp
index 0d312a8..8029f20 100644
--- a/include/iota/api/requests/get_balances.hpp
+++ b/include/iota/api/requests/get_balances.hpp
@@ -67,7 +67,7 @@ class GetBalances : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/get_inclusion_states.hpp b/include/iota/api/requests/get_inclusion_states.hpp
index 17f1947..410d026 100644
--- a/include/iota/api/requests/get_inclusion_states.hpp
+++ b/include/iota/api/requests/get_inclusion_states.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/requests/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -68,7 +70,7 @@ class GetInclusionStates : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/get_transactions_to_approve.hpp b/include/iota/api/requests/get_transactions_to_approve.hpp
index 3b899b2..8132f57 100644
--- a/include/iota/api/requests/get_transactions_to_approve.hpp
+++ b/include/iota/api/requests/get_transactions_to_approve.hpp
@@ -63,7 +63,7 @@ class GetTransactionsToApprove : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/get_trytes.hpp b/include/iota/api/requests/get_trytes.hpp
index c8f2384..1b819a5 100644
--- a/include/iota/api/requests/get_trytes.hpp
+++ b/include/iota/api/requests/get_trytes.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/requests/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -62,7 +64,7 @@ class GetTrytes : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/remove_neighbors.hpp b/include/iota/api/requests/remove_neighbors.hpp
index 4e425e2..99ae012 100644
--- a/include/iota/api/requests/remove_neighbors.hpp
+++ b/include/iota/api/requests/remove_neighbors.hpp
@@ -27,6 +27,8 @@
 
 #include <iota/api/requests/base.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -61,7 +63,7 @@ class RemoveNeighbors : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/requests/store_transactions.hpp b/include/iota/api/requests/store_transactions.hpp
index c757919..865987c 100644
--- a/include/iota/api/requests/store_transactions.hpp
+++ b/include/iota/api/requests/store_transactions.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/requests/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -62,7 +64,7 @@ class StoreTransactions : public Base {
    *
    * @param data where to store serialisation.
    */
-  void serialize(json& data) const override;
+  void serialize(Utils::json& data) const override;
 
 public:
   /**
diff --git a/include/iota/api/responses/add_neighbors.hpp b/include/iota/api/responses/add_neighbors.hpp
index 3cc4dff..014f42e 100644
--- a/include/iota/api/responses/add_neighbors.hpp
+++ b/include/iota/api/responses/add_neighbors.hpp
@@ -55,7 +55,7 @@ class AddNeighbors : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit AddNeighbors(const json& res);
+  explicit AddNeighbors(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -68,7 +68,7 @@ class AddNeighbors : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/attach_to_tangle.hpp b/include/iota/api/responses/attach_to_tangle.hpp
index 7e5f9e8..4d5e49a 100644
--- a/include/iota/api/responses/attach_to_tangle.hpp
+++ b/include/iota/api/responses/attach_to_tangle.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -62,7 +64,7 @@ class AttachToTangle : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit AttachToTangle(const json& res);
+  explicit AttachToTangle(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -75,7 +77,7 @@ class AttachToTangle : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/base.hpp b/include/iota/api/responses/base.hpp
index 562aa9b..a10057f 100644
--- a/include/iota/api/responses/base.hpp
+++ b/include/iota/api/responses/base.hpp
@@ -27,9 +27,7 @@
 
 #include <cstdint>
 
-#include <json.hpp>
-
-using json = nlohmann::json;
+#include <iota/utils/json.hpp>
 
 namespace IOTA {
 
@@ -54,7 +52,7 @@ class Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit Base(const json& res);
+  explicit Base(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -67,7 +65,7 @@ class Base {
    *
    * @param res json data to be used for deserialization.
    */
-  virtual void deserialize(const json& res);
+  virtual void deserialize(const Utils::json& res);
 
 public:
   /**
diff --git a/include/iota/api/responses/find_transactions.hpp b/include/iota/api/responses/find_transactions.hpp
index 461f4c1..6f215a6 100644
--- a/include/iota/api/responses/find_transactions.hpp
+++ b/include/iota/api/responses/find_transactions.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -58,7 +60,7 @@ class FindTransactions : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit FindTransactions(const json& res);
+  explicit FindTransactions(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -71,7 +73,7 @@ class FindTransactions : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/get_account_data.hpp b/include/iota/api/responses/get_account_data.hpp
index 0c986ce..e1fa85b 100644
--- a/include/iota/api/responses/get_account_data.hpp
+++ b/include/iota/api/responses/get_account_data.hpp
@@ -29,6 +29,8 @@
 #include <iota/models/fwd.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
diff --git a/include/iota/api/responses/get_balances.hpp b/include/iota/api/responses/get_balances.hpp
index 2873cfa..6d7331a 100644
--- a/include/iota/api/responses/get_balances.hpp
+++ b/include/iota/api/responses/get_balances.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -60,7 +62,7 @@ class GetBalances : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit GetBalances(const json& res);
+  explicit GetBalances(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -73,7 +75,7 @@ class GetBalances : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/get_balances_and_format.hpp b/include/iota/api/responses/get_balances_and_format.hpp
index 3378442..19fd9c9 100644
--- a/include/iota/api/responses/get_balances_and_format.hpp
+++ b/include/iota/api/responses/get_balances_and_format.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/models/fwd.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
diff --git a/include/iota/api/responses/get_bundle.hpp b/include/iota/api/responses/get_bundle.hpp
index 8fe75a7..a8565a2 100644
--- a/include/iota/api/responses/get_bundle.hpp
+++ b/include/iota/api/responses/get_bundle.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/models/fwd.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
diff --git a/include/iota/api/responses/get_inclusion_states.hpp b/include/iota/api/responses/get_inclusion_states.hpp
index f888e1c..8b49679 100644
--- a/include/iota/api/responses/get_inclusion_states.hpp
+++ b/include/iota/api/responses/get_inclusion_states.hpp
@@ -27,6 +27,8 @@
 
 #include <iota/api/responses/base.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -59,7 +61,7 @@ class GetInclusionStates : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit GetInclusionStates(const json& res);
+  explicit GetInclusionStates(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -72,7 +74,7 @@ class GetInclusionStates : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/get_neighbors.hpp b/include/iota/api/responses/get_neighbors.hpp
index e51e09b..f5e5135 100644
--- a/include/iota/api/responses/get_neighbors.hpp
+++ b/include/iota/api/responses/get_neighbors.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/models/fwd.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -56,7 +58,7 @@ class GetNeighbors : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit GetNeighbors(const json& res);
+  explicit GetNeighbors(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -69,7 +71,7 @@ class GetNeighbors : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/get_node_info.hpp b/include/iota/api/responses/get_node_info.hpp
index 8de22dd..a7259a3 100644
--- a/include/iota/api/responses/get_node_info.hpp
+++ b/include/iota/api/responses/get_node_info.hpp
@@ -80,7 +80,7 @@ class GetNodeInfo : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit GetNodeInfo(const json& res);
+  explicit GetNodeInfo(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -93,7 +93,7 @@ class GetNodeInfo : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/get_tips.hpp b/include/iota/api/responses/get_tips.hpp
index b70d2f6..8952041 100644
--- a/include/iota/api/responses/get_tips.hpp
+++ b/include/iota/api/responses/get_tips.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -55,7 +57,7 @@ class GetTips : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit GetTips(const json& res);
+  explicit GetTips(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -68,7 +70,7 @@ class GetTips : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/get_transactions_to_approve.hpp b/include/iota/api/responses/get_transactions_to_approve.hpp
index f63751d..f2e856e 100644
--- a/include/iota/api/responses/get_transactions_to_approve.hpp
+++ b/include/iota/api/responses/get_transactions_to_approve.hpp
@@ -60,7 +60,7 @@ class GetTransactionsToApprove : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit GetTransactionsToApprove(const json& res);
+  explicit GetTransactionsToApprove(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -73,7 +73,7 @@ class GetTransactionsToApprove : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/get_transfers.hpp b/include/iota/api/responses/get_transfers.hpp
index 46d80f0..d3945d7 100644
--- a/include/iota/api/responses/get_transfers.hpp
+++ b/include/iota/api/responses/get_transfers.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/models/fwd.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
diff --git a/include/iota/api/responses/get_trytes.hpp b/include/iota/api/responses/get_trytes.hpp
index 0684b21..a76b391 100644
--- a/include/iota/api/responses/get_trytes.hpp
+++ b/include/iota/api/responses/get_trytes.hpp
@@ -28,6 +28,8 @@
 #include <iota/api/responses/base.hpp>
 #include <iota/types/trytes.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
@@ -56,7 +58,7 @@ class GetTrytes : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit GetTrytes(const json& res);
+  explicit GetTrytes(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -69,7 +71,7 @@ class GetTrytes : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/remove_neighbors.hpp b/include/iota/api/responses/remove_neighbors.hpp
index 3862f47..d0547ae 100644
--- a/include/iota/api/responses/remove_neighbors.hpp
+++ b/include/iota/api/responses/remove_neighbors.hpp
@@ -55,7 +55,7 @@ class RemoveNeighbors : public Base {
    *
    * @param res json to be used for deserialization.
    */
-  explicit RemoveNeighbors(const json& res);
+  explicit RemoveNeighbors(const Utils::json& res);
 
   /**
    * Default dtor.
@@ -68,7 +68,7 @@ class RemoveNeighbors : public Base {
    *
    * @param res json data to be used for deserialization.
    */
-  void deserialize(const json& res) override;
+  void deserialize(const Utils::json& res) override;
 
 public:
   /**
diff --git a/include/iota/api/responses/replay_bundle.hpp b/include/iota/api/responses/replay_bundle.hpp
index 47b4c1b..f39c155 100644
--- a/include/iota/api/responses/replay_bundle.hpp
+++ b/include/iota/api/responses/replay_bundle.hpp
@@ -27,6 +27,8 @@
 
 #include <iota/api/responses/base.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
diff --git a/include/iota/api/responses/send_transfer.hpp b/include/iota/api/responses/send_transfer.hpp
index cebf23a..d9a1cd1 100644
--- a/include/iota/api/responses/send_transfer.hpp
+++ b/include/iota/api/responses/send_transfer.hpp
@@ -27,6 +27,8 @@
 
 #include <iota/api/responses/base.hpp>
 
+#include <vector>
+
 namespace IOTA {
 
 namespace API {
diff --git a/include/iota/api/service.hpp b/include/iota/api/service.hpp
index 6debb08..8417d02 100644
--- a/include/iota/api/service.hpp
+++ b/include/iota/api/service.hpp
@@ -26,7 +26,6 @@
 #pragma once
 
 #include <cpr/cpr.h>
-#include <json.hpp>
 
 #include <iota/constants.hpp>
 #include <iota/errors/bad_request.hpp>
@@ -34,8 +33,7 @@
 #include <iota/errors/network.hpp>
 #include <iota/errors/unauthorized.hpp>
 #include <iota/errors/unrecognized.hpp>
-
-using json = nlohmann::json;
+#include <iota/utils/json.hpp>
 
 namespace IOTA {
 
@@ -71,11 +69,11 @@ class Service {
   Response request(Args&&... args) const {
     auto request = Request{ args... };
 
-    json data;
+    Utils::json data;
     request.serialize(data);
 
     auto url     = cpr::Url{ "http://" + host_ + ":" + std::to_string(port_) };
-    auto body    = cpr::Body{ data.dump() };
+    auto body    = cpr::Body{ data.dumps() };
     auto headers = cpr::Header{ { "Content-Type", "application/json" },
                                 { "Content-Length", std::to_string(body.size()) },
                                 { "X-IOTA-API-Version", APIVersion } };
@@ -84,14 +82,13 @@ class Service {
     if (res.error.code != cpr::ErrorCode::OK)
       throw Errors::Network(res.error.message);
 
-    json        resJson;
     std::string error;
 
     try {
-      resJson = json::parse(res.text);
+      data.loads(res.text);
 
-      if (resJson.count("error")) {
-        error = resJson["error"].get<std::string>();
+      if (data.has("error")) {
+        error = data.getString("error");
       }
     } catch (const std::runtime_error&) {
       if (res.elapsed >= timeout_) {
@@ -104,7 +101,7 @@ class Service {
     Response response;
     switch (res.status_code) {
       case 200:
-        return Response{ resJson };
+        return Response{ data };
       case 400:
         throw Errors::BadRequest(error);
       case 401:
@@ -127,10 +124,12 @@ class Service {
    * Host of the node.
    */
   std::string host_;
+
   /**
    * Port of the node.
    */
   unsigned int port_;
+
   /**
    * Timeout for requests.
    */
diff --git a/include/iota/utils/json.hpp b/include/iota/utils/json.hpp
new file mode 100644
index 0000000..172ec4e
--- /dev/null
+++ b/include/iota/utils/json.hpp
@@ -0,0 +1,218 @@
+//
+// MIT License
+//
+// Copyright (c) 2017-2018 Thibault Martinez and Simon Ninon
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+//
+
+#pragma once
+
+#include <functional>
+#include <string>
+#include <vector>
+
+#include <rapidjson/document.h>
+#include <rapidjson/rapidjson.h>
+#include <rapidjson/stringbuffer.h>
+#include <rapidjson/writer.h>
+
+namespace IOTA {
+
+namespace Utils {
+
+/**
+ * json 3rd party library wrapper
+ * hides some internal mechanisms related to the json library
+ * also makes it easier to switch from one libary to another in the future
+ */
+class json {
+public:
+  /**
+   * Default ctor
+   */
+  json(void);
+
+  /**
+   * Default dtor
+   */
+  ~json(void) = default;
+
+  /**
+   * Move constructor
+   */
+  json(json&&) = default;
+
+  /**
+   * Move operator
+   */
+  json& operator=(json&&) = default;
+
+  /**
+   * Disabled copy constructor to ensure memory efficiency
+   */
+  json(const json&) = delete;
+
+  /**
+   * Disabled assignment operator to ensure memory efficiency
+   */
+  json& operator=(const json&) = delete;
+
+private:
+  /**
+   * ctor from json value
+   * move the json value
+   */
+  json(const rapidjson::Value& val);
+
+public:
+  /**
+   * parse the given json string and loads the content in the current object
+   * @param json_str  the json string to be parsed
+   */
+  void loads(const std::string& json_str);
+
+  /**
+   * convert the json object into a json string
+   * @return the converted json string
+   */
+  std::string dumps(void) const;
+
+public:
+  /**
+   * check key existence in json object
+   * @param the key to check
+   * @return whether the object contains the given key
+   */
+  bool has(const std::string& key) const;
+
+public:
+  /**
+   * set the key with the integer value
+   * @param key    the key to be set
+   * @param value  the value to set the key with
+   */
+  void set(const std::string& key, int64_t value);
+
+  /**
+   * set the key with the string value
+   * @param key   the key to be set
+   * @param value  the value to set the key with
+   */
+  void set(const std::string& key, const std::string& value);
+
+  /**
+   * set the key with the string array value
+   * @param key    the key to be set
+   * @param value  the value to set the key with
+   */
+  void set(const std::string& key, const std::vector<std::string>& value);
+
+  /**
+   * set the key with the bool array value
+   * @param key    the key to be set
+   * @param value  the value to set the key with
+   */
+  void set(const std::string& key, const std::vector<bool>& value);
+
+  /**
+   * set the key with the json array value
+   * @param key    the key to be set
+   * @param value  the value to set the key with
+   */
+  void set(const std::string& key, std::vector<json>& value);
+
+  /**
+   * set the key with the string array value
+   * takes as input an array of any model and a function converting each item into a string
+   * @param key        the key to be set
+   * @param value      the value to set the key with
+   * @param converter  function called on each item of value to convert them to string
+   */
+  template <typename T>
+  void set(const std::string& key, const std::vector<T>& value,
+           const std::function<std::string(const T&)>& converter) {
+    auto arr     = rapidjson::Value{ rapidjson::kArrayType };
+    auto key_val = rapidjson::Value{ key.data(), memory_pool_ };
+
+    for (const auto& val : value) {
+      arr.PushBack(rapidjson::Value(converter(val).data(), memory_pool_).Move(), memory_pool_);
+    }
+
+    json_.AddMember(key_val.Move(), arr.Move(), memory_pool_);
+  }
+
+public:
+  /**
+   * get an integer value for the given key
+   * assumption is made that key exists (this function will **not** check for existence)
+   * @param key  the key to retrieve
+   * @return the retrieved value
+   */
+  int64_t getInt(const std::string& key) const;
+
+  /**
+   * get a string value for the given key
+   * assumption is made that key exists (this function will **not** check for existence)
+   * @param key  the key to retrieve
+   * @return the retrieved value
+   */
+  std::string getString(const std::string& key) const;
+
+  /**
+   * get a string vector value for the given key
+   * assumption is made that key exists (this function will **not** check for existence)
+   * @param key  the key to retrieve
+   * @return the retrieved value
+   */
+  std::vector<std::string> getStringVector(const std::string& key) const;
+
+  /**
+   * get a boolean vector value for the given key
+   * assumption is made that key exists (this function will **not** check for existence)
+   * @param key  the key to retrieve
+   * @return the retrieved value
+   */
+  std::vector<bool> getBoolVector(const std::string& key) const;
+
+  /**
+   * get a json vector value for the given key
+   * assumption is made that key exists (this function will **not** check for existence)
+   * @param key  the key to retrieve
+   * @return the retrieved value
+   */
+  std::vector<json> getJsonVector(const std::string& key) const;
+
+private:
+  /**
+   * json memory pool, shared among all json objects
+   */
+  static rapidjson::MemoryPoolAllocator<> memory_pool_;
+
+private:
+  /**
+   * the json object itself
+   */
+  rapidjson::Document json_;
+};
+
+}  // namespace Utils
+
+}  // namespace IOTA
diff --git a/source/api/extended.cpp b/source/api/extended.cpp
index 87070af..6861625 100644
--- a/source/api/extended.cpp
+++ b/source/api/extended.cpp
@@ -23,6 +23,7 @@
 //
 //
 
+#include <cmath>
 #include <iostream>
 
 #include <iota/api/extended.hpp>
diff --git a/source/api/requests/add_neighbors.cpp b/source/api/requests/add_neighbors.cpp
index 4b080c2..4373c3b 100644
--- a/source/api/requests/add_neighbors.cpp
+++ b/source/api/requests/add_neighbors.cpp
@@ -36,9 +36,10 @@ AddNeighbors::AddNeighbors(const std::vector<std::string>& uris)
 }
 
 void
-AddNeighbors::serialize(json& data) const {
+AddNeighbors::serialize(Utils::json& data) const {
   Base::serialize(data);
-  data["uris"] = uris_;
+
+  data.set("uris", uris_);
 }
 
 const std::vector<std::string>&
diff --git a/source/api/requests/attach_to_tangle.cpp b/source/api/requests/attach_to_tangle.cpp
index 7d7fcb2..aa1ecdb 100644
--- a/source/api/requests/attach_to_tangle.cpp
+++ b/source/api/requests/attach_to_tangle.cpp
@@ -43,12 +43,13 @@ AttachToTangle::AttachToTangle(const Types::Trytes&              trunkTransactio
 }
 
 void
-AttachToTangle::serialize(json& data) const {
+AttachToTangle::serialize(Utils::json& data) const {
   Base::serialize(data);
-  data["trunkTransaction"]   = trunkTransaction_;
-  data["branchTransaction"]  = branchTransaction_;
-  data["minWeightMagnitude"] = minWeightMagnitude_;
-  data["trytes"]             = trytes_;
+
+  data.set("trunkTransaction", trunkTransaction_);
+  data.set("branchTransaction", branchTransaction_);
+  data.set("minWeightMagnitude", minWeightMagnitude_);
+  data.set("trytes", trytes_);
 }
 
 const Types::Trytes&
diff --git a/source/api/requests/base.cpp b/source/api/requests/base.cpp
index 5ad6b60..a060f47 100644
--- a/source/api/requests/base.cpp
+++ b/source/api/requests/base.cpp
@@ -35,8 +35,8 @@ Base::Base(const std::string& command) : command_(command) {
 }
 
 void
-Base::serialize(json& data) const {
-  data = json{ { "command", command_ } };
+Base::serialize(Utils::json& data) const {
+  data.set("command", command_);
 }
 
 const std::string&
diff --git a/source/api/requests/broadcast_transactions.cpp b/source/api/requests/broadcast_transactions.cpp
index 3a566af..2f5470d 100644
--- a/source/api/requests/broadcast_transactions.cpp
+++ b/source/api/requests/broadcast_transactions.cpp
@@ -36,9 +36,10 @@ BroadcastTransactions::BroadcastTransactions(const std::vector<Types::Trytes>& t
 }
 
 void
-BroadcastTransactions::serialize(json& data) const {
+BroadcastTransactions::serialize(Utils::json& data) const {
   Base::serialize(data);
-  data["trytes"] = trytes_;
+
+  data.set("trytes", trytes_);
 }
 
 const std::vector<Types::Trytes>&
diff --git a/source/api/requests/find_transactions.cpp b/source/api/requests/find_transactions.cpp
index 51ab77b..a9693e3 100644
--- a/source/api/requests/find_transactions.cpp
+++ b/source/api/requests/find_transactions.cpp
@@ -43,27 +43,25 @@ FindTransactions::FindTransactions(const std::vector<Models::Address>& addresses
 }
 
 void
-FindTransactions::serialize(json& data) const {
+FindTransactions::serialize(Utils::json& data) const {
   Base::serialize(data);
 
   if (!addresses_.empty()) {
-    for (auto& address : addresses_) {
-      data["addresses"].emplace_back(address.toTrytes());
-    }
+    data.set<Models::Address>("addresses", addresses_,
+                              [](const Models::Address& addr) { return addr.toTrytes(); });
   }
 
   if (!tags_.empty()) {
-    for (const auto& tag : tags_) {
-      data["tags"].emplace_back(tag.toTrytesWithPadding());
-    }
+    data.set<Models::Tag>("tags", tags_,
+                          [](const Models::Tag& tag) { return tag.toTrytesWithPadding(); });
   }
 
   if (!approvees_.empty()) {
-    data["approvees"] = approvees_;
+    data.set("approvees", approvees_);
   }
 
   if (!bundles_.empty()) {
-    data["bundles"] = bundles_;
+    data.set("bundles", bundles_);
   }
 }
 
diff --git a/source/api/requests/get_balances.cpp b/source/api/requests/get_balances.cpp
index cb38e3b..057d7e0 100644
--- a/source/api/requests/get_balances.cpp
+++ b/source/api/requests/get_balances.cpp
@@ -36,13 +36,12 @@ GetBalances::GetBalances(const std::vector<Models::Address>& addresses, const in
 }
 
 void
-GetBalances::serialize(json& data) const {
+GetBalances::serialize(Utils::json& data) const {
   Base::serialize(data);
 
-  for (auto& address : addresses_) {
-    data["addresses"].emplace_back(address.toTrytes());
-  }
-  data["threshold"] = threshold_;
+  data.set<Models::Address>("addresses", addresses_,
+                            [](const Models::Address& addr) { return addr.toTrytes(); });
+  data.set("threshold", threshold_);
 }
 
 const std::vector<Models::Address>&
diff --git a/source/api/requests/get_inclusions_states.cpp b/source/api/requests/get_inclusions_states.cpp
index 52b40a3..0d86a76 100644
--- a/source/api/requests/get_inclusions_states.cpp
+++ b/source/api/requests/get_inclusions_states.cpp
@@ -38,10 +38,11 @@ GetInclusionStates::GetInclusionStates(const std::vector<Types::Trytes>& transac
 }
 
 void
-GetInclusionStates::serialize(json& data) const {
+GetInclusionStates::serialize(Utils::json& data) const {
   Base::serialize(data);
-  data["transactions"] = transactions_;
-  data["tips"]         = tips_;
+
+  data.set("transactions", transactions_);
+  data.set("tips", tips_);
 }
 
 const std::vector<Types::Trytes>&
diff --git a/source/api/requests/get_transactions_to_approve.cpp b/source/api/requests/get_transactions_to_approve.cpp
index 5a37cad..4c31879 100644
--- a/source/api/requests/get_transactions_to_approve.cpp
+++ b/source/api/requests/get_transactions_to_approve.cpp
@@ -36,9 +36,10 @@ GetTransactionsToApprove::GetTransactionsToApprove(const int& depth)
 }
 
 void
-GetTransactionsToApprove::serialize(json& data) const {
+GetTransactionsToApprove::serialize(Utils::json& data) const {
   Base::serialize(data);
-  data["depth"] = depth_;
+
+  data.set("depth", depth_);
 }
 
 int
diff --git a/source/api/requests/get_trytes.cpp b/source/api/requests/get_trytes.cpp
index 46cc8ec..7e1e6b6 100644
--- a/source/api/requests/get_trytes.cpp
+++ b/source/api/requests/get_trytes.cpp
@@ -36,9 +36,10 @@ GetTrytes::GetTrytes(const std::vector<Types::Trytes>& hashes)
 }
 
 void
-GetTrytes::serialize(json& data) const {
+GetTrytes::serialize(Utils::json& data) const {
   Base::serialize(data);
-  data["hashes"] = hashes_;
+
+  data.set("hashes", hashes_);
 }
 
 const std::vector<Types::Trytes>&
diff --git a/source/api/requests/remove_neighbors.cpp b/source/api/requests/remove_neighbors.cpp
index cd91011..75c1a28 100644
--- a/source/api/requests/remove_neighbors.cpp
+++ b/source/api/requests/remove_neighbors.cpp
@@ -36,9 +36,10 @@ RemoveNeighbors::RemoveNeighbors(const std::vector<std::string>& uris)
 }
 
 void
-RemoveNeighbors::serialize(json& data) const {
+RemoveNeighbors::serialize(Utils::json& data) const {
   Base::serialize(data);
-  data["uris"] = uris_;
+
+  data.set("uris", uris_);
 }
 
 const std::vector<std::string>&
diff --git a/source/api/requests/store_transactions.cpp b/source/api/requests/store_transactions.cpp
index f5102a6..2273072 100644
--- a/source/api/requests/store_transactions.cpp
+++ b/source/api/requests/store_transactions.cpp
@@ -36,9 +36,10 @@ StoreTransactions::StoreTransactions(const std::vector<Types::Trytes>& trytes)
 }
 
 void
-StoreTransactions::serialize(json& data) const {
+StoreTransactions::serialize(Utils::json& data) const {
   Base::serialize(data);
-  data["trytes"] = trytes_;
+
+  data.set("trytes", trytes_);
 }
 
 const std::vector<Types::Trytes>&
diff --git a/source/api/responses/add_neighbors.cpp b/source/api/responses/add_neighbors.cpp
index f9bb8cc..4c02c9a 100644
--- a/source/api/responses/add_neighbors.cpp
+++ b/source/api/responses/add_neighbors.cpp
@@ -34,16 +34,16 @@ namespace Responses {
 AddNeighbors::AddNeighbors(const int64_t& addedNeighbors) : addedNeighbors_(addedNeighbors) {
 }
 
-AddNeighbors::AddNeighbors(const json& res) {
+AddNeighbors::AddNeighbors(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-AddNeighbors::deserialize(const json& res) {
+AddNeighbors::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("addedNeighbors")) {
-    addedNeighbors_ = res.at("addedNeighbors").get<int64_t>();
+  if (res.has("addedNeighbors")) {
+    addedNeighbors_ = res.getInt("addedNeighbors");
   }
 }
 
diff --git a/source/api/responses/attach_to_tangle.cpp b/source/api/responses/attach_to_tangle.cpp
index ae838e9..5c5a006 100644
--- a/source/api/responses/attach_to_tangle.cpp
+++ b/source/api/responses/attach_to_tangle.cpp
@@ -34,16 +34,16 @@ namespace Responses {
 AttachToTangle::AttachToTangle(const std::vector<Types::Trytes>& trytes) : trytes_(trytes) {
 }
 
-AttachToTangle::AttachToTangle(const json& res) {
+AttachToTangle::AttachToTangle(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-AttachToTangle::deserialize(const json& res) {
+AttachToTangle::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("trytes")) {
-    trytes_ = res.at("trytes").get<std::vector<Types::Trytes>>();
+  if (res.has("trytes")) {
+    trytes_ = res.getStringVector("trytes");
   }
 }
 
diff --git a/source/api/responses/base.cpp b/source/api/responses/base.cpp
index 869ead9..f67e285 100644
--- a/source/api/responses/base.cpp
+++ b/source/api/responses/base.cpp
@@ -34,14 +34,14 @@ namespace Responses {
 Base::Base(const int64_t& duration) : duration_(duration) {
 }
 
-Base::Base(const json& res) {
+Base::Base(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-Base::deserialize(const json& res) {
-  if (res.count("duration")) {
-    duration_ = res.at("duration").get<long>();
+Base::deserialize(const Utils::json& res) {
+  if (res.has("duration")) {
+    duration_ = res.getInt("duration");
   }
 }
 
diff --git a/source/api/responses/find_transactions.cpp b/source/api/responses/find_transactions.cpp
index 992a658..ed06ec6 100644
--- a/source/api/responses/find_transactions.cpp
+++ b/source/api/responses/find_transactions.cpp
@@ -34,16 +34,16 @@ namespace Responses {
 FindTransactions::FindTransactions(const std::vector<Types::Trytes>& hashes) : hashes_(hashes) {
 }
 
-FindTransactions::FindTransactions(const json& res) {
+FindTransactions::FindTransactions(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-FindTransactions::deserialize(const json& res) {
+FindTransactions::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("hashes")) {
-    hashes_ = res.at("hashes").get<std::vector<Types::Trytes>>();
+  if (res.has("hashes")) {
+    hashes_ = res.getStringVector("hashes");
   }
 }
 
diff --git a/source/api/responses/get_balances.cpp b/source/api/responses/get_balances.cpp
index f629b12..7ffcd50 100644
--- a/source/api/responses/get_balances.cpp
+++ b/source/api/responses/get_balances.cpp
@@ -36,24 +36,24 @@ GetBalances::GetBalances(const std::vector<std::string>& balances, const Types::
     : balances_(balances), milestone_(milestone), milestoneIndex_(milestoneIndex) {
 }
 
-GetBalances::GetBalances(const json& res) {
+GetBalances::GetBalances(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-GetBalances::deserialize(const json& res) {
+GetBalances::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("balances")) {
-    balances_ = res.at("balances").get<std::vector<std::string>>();
+  if (res.has("balances")) {
+    balances_ = res.getStringVector("balances");
   }
 
-  if (res.count("milestone")) {
-    milestone_ = res.at("milestone").get<Types::Trytes>();
+  if (res.has("milestone")) {
+    milestone_ = res.getString("milestone");
   }
 
-  if (res.count("milestoneIndex")) {
-    milestoneIndex_ = res.at("milestoneIndex").get<int64_t>();
+  if (res.has("milestoneIndex")) {
+    milestoneIndex_ = res.getInt("milestoneIndex");
   }
 }
 
diff --git a/source/api/responses/get_inclusion_states.cpp b/source/api/responses/get_inclusion_states.cpp
index c50e2a0..f6e0d3f 100644
--- a/source/api/responses/get_inclusion_states.cpp
+++ b/source/api/responses/get_inclusion_states.cpp
@@ -34,16 +34,16 @@ namespace Responses {
 GetInclusionStates::GetInclusionStates(const std::vector<bool>& states) : states_(states) {
 }
 
-GetInclusionStates::GetInclusionStates(const json& res) {
+GetInclusionStates::GetInclusionStates(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-GetInclusionStates::deserialize(const json& res) {
+GetInclusionStates::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("states")) {
-    states_ = res.at("states").get<std::vector<bool>>();
+  if (res.has("states")) {
+    states_ = res.getBoolVector("states");
   }
 }
 
diff --git a/source/api/responses/get_neighbors.cpp b/source/api/responses/get_neighbors.cpp
index 805d0fc..26fee43 100644
--- a/source/api/responses/get_neighbors.cpp
+++ b/source/api/responses/get_neighbors.cpp
@@ -35,30 +35,31 @@ namespace Responses {
 GetNeighbors::GetNeighbors(const std::vector<Models::Neighbor>& neighbors) : neighbors_(neighbors) {
 }
 
-GetNeighbors::GetNeighbors(const json& res) {
+GetNeighbors::GetNeighbors(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-GetNeighbors::deserialize(const json& res) {
+GetNeighbors::deserialize(const Utils::json& res) {
   Base::deserialize(res);
-  for (const auto& neighbor : res["neighbors"]) {
+
+  for (const auto& neighbor : res.getJsonVector("neighbors")) {
     Models::Neighbor obj;
 
-    if (neighbor.count("address")) {
-      obj.setAddress(neighbor.at("address").get<Types::Trytes>());
+    if (neighbor.has("address")) {
+      obj.setAddress(neighbor.getString("address"));
     }
 
-    if (neighbor.count("numberOfAllTransactions")) {
-      obj.setNumberOfAllTransactions(neighbor.at("numberOfAllTransactions").get<int64_t>());
+    if (neighbor.has("numberOfAllTransactions")) {
+      obj.setNumberOfAllTransactions(neighbor.getInt("numberOfAllTransactions"));
     }
 
-    if (neighbor.count("numberOfInvalidTransactions")) {
-      obj.setNumberOfInvalidTransactions(neighbor.at("numberOfInvalidTransactions").get<int64_t>());
+    if (neighbor.has("numberOfInvalidTransactions")) {
+      obj.setNumberOfInvalidTransactions(neighbor.getInt("numberOfInvalidTransactions"));
     }
 
-    if (neighbor.count("numberOfNewTransactions")) {
-      obj.setNumberOfNewTransactions(neighbor.at("numberOfNewTransactions").get<int64_t>());
+    if (neighbor.has("numberOfNewTransactions")) {
+      obj.setNumberOfNewTransactions(neighbor.getInt("numberOfNewTransactions"));
     }
 
     neighbors_.push_back(std::move(obj));
diff --git a/source/api/responses/get_node_info.cpp b/source/api/responses/get_node_info.cpp
index 09fb853..a1079c1 100644
--- a/source/api/responses/get_node_info.cpp
+++ b/source/api/responses/get_node_info.cpp
@@ -56,73 +56,72 @@ GetNodeInfo::GetNodeInfo(const std::string& appName, const std::string& appVersi
       transactionsToRequest_(transactionsToRequest) {
 }
 
-GetNodeInfo::GetNodeInfo(const json& res) {
+GetNodeInfo::GetNodeInfo(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-GetNodeInfo::deserialize(const json& res) {
+GetNodeInfo::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("appName")) {
-    appName_ = res.at("appName").get<std::string>();
+  if (res.has("appName")) {
+    appName_ = res.getString("appName");
   }
 
-  if (res.count("appVersion")) {
-    appVersion_ = res.at("appVersion").get<std::string>();
+  if (res.has("appVersion")) {
+    appVersion_ = res.getString("appVersion");
   }
 
-  if (res.count("jreAvailableProcessors")) {
-    jreAvailableProcessors_ = res.at("jreAvailableProcessors").get<int64_t>();
+  if (res.has("jreAvailableProcessors")) {
+    jreAvailableProcessors_ = res.getInt("jreAvailableProcessors");
   }
 
-  if (res.count("jreFreeMemory")) {
-    jreFreeMemory_ = res.at("jreFreeMemory").get<int64_t>();
+  if (res.has("jreFreeMemory")) {
+    jreFreeMemory_ = res.getInt("jreFreeMemory");
   }
 
-  if (res.count("jreMaxMemory")) {
-    jreMaxMemory_ = res.at("jreMaxMemory").get<int64_t>();
+  if (res.has("jreMaxMemory")) {
+    jreMaxMemory_ = res.getInt("jreMaxMemory");
   }
 
-  if (res.count("jreTotalMemory")) {
-    jreTotalMemory_ = res.at("jreTotalMemory").get<int64_t>();
+  if (res.has("jreTotalMemory")) {
+    jreTotalMemory_ = res.getInt("jreTotalMemory");
   }
 
-  if (res.count("latestMilestone")) {
-    latestMilestone_ = res.at("latestMilestone").get<Types::Trytes>();
+  if (res.has("latestMilestone")) {
+    latestMilestone_ = res.getString("latestMilestone");
   }
 
-  if (res.count("latestMilestoneIndex")) {
-    latestMilestoneIndex_ = res.at("latestMilestoneIndex").get<int64_t>();
+  if (res.has("latestMilestoneIndex")) {
+    latestMilestoneIndex_ = res.getInt("latestMilestoneIndex");
   }
 
-  if (res.count("latestSolidSubtangleMilestone")) {
-    latestSolidSubtangleMilestone_ = res.at("latestSolidSubtangleMilestone").get<Types::Trytes>();
+  if (res.has("latestSolidSubtangleMilestone")) {
+    latestSolidSubtangleMilestone_ = res.getString("latestSolidSubtangleMilestone");
   }
 
-  if (res.count("latestSolidSubtangleMilestoneIndex")) {
-    latestSolidSubtangleMilestoneIndex_ =
-        res.at("latestSolidSubtangleMilestoneIndex").get<int64_t>();
+  if (res.has("latestSolidSubtangleMilestoneIndex")) {
+    latestSolidSubtangleMilestoneIndex_ = res.getInt("latestSolidSubtangleMilestoneIndex");
   }
 
-  if (res.count("neighbors")) {
-    neighbors_ = res.at("neighbors").get<int64_t>();
+  if (res.has("neighbors")) {
+    neighbors_ = res.getInt("neighbors");
   }
 
-  if (res.count("packetsQueueSize")) {
-    packetsQueueSize_ = res.at("packetsQueueSize").get<int64_t>();
+  if (res.has("packetsQueueSize")) {
+    packetsQueueSize_ = res.getInt("packetsQueueSize");
   }
 
-  if (res.count("time")) {
-    time_ = res.at("time").get<int64_t>();
+  if (res.has("time")) {
+    time_ = res.getInt("time");
   }
 
-  if (res.count("tips")) {
-    tips_ = res.at("tips").get<int64_t>();
+  if (res.has("tips")) {
+    tips_ = res.getInt("tips");
   }
 
-  if (res.count("transactionsToRequest")) {
-    transactionsToRequest_ = res.at("transactionsToRequest").get<int64_t>();
+  if (res.has("transactionsToRequest")) {
+    transactionsToRequest_ = res.getInt("transactionsToRequest");
   }
 }
 
diff --git a/source/api/responses/get_tips.cpp b/source/api/responses/get_tips.cpp
index e8ecb42..bc0995a 100644
--- a/source/api/responses/get_tips.cpp
+++ b/source/api/responses/get_tips.cpp
@@ -34,16 +34,16 @@ namespace Responses {
 GetTips::GetTips(const std::vector<Types::Trytes>& hashes) : hashes_(hashes) {
 }
 
-GetTips::GetTips(const json& res) {
+GetTips::GetTips(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-GetTips::deserialize(const json& res) {
+GetTips::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("hashes")) {
-    hashes_ = res.at("hashes").get<std::vector<Types::Trytes>>();
+  if (res.has("hashes")) {
+    hashes_ = res.getStringVector("hashes");
   }
 }
 
diff --git a/source/api/responses/get_transactions_to_approve.cpp b/source/api/responses/get_transactions_to_approve.cpp
index 0259053..f4c1899 100644
--- a/source/api/responses/get_transactions_to_approve.cpp
+++ b/source/api/responses/get_transactions_to_approve.cpp
@@ -36,20 +36,20 @@ GetTransactionsToApprove::GetTransactionsToApprove(const Types::Trytes& trunkTra
     : trunkTransaction_(trunkTransaction), branchTransaction_(branchTransaction) {
 }
 
-GetTransactionsToApprove::GetTransactionsToApprove(const json& res) {
+GetTransactionsToApprove::GetTransactionsToApprove(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-GetTransactionsToApprove::deserialize(const json& res) {
+GetTransactionsToApprove::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("trunkTransaction")) {
-    trunkTransaction_ = res.at("trunkTransaction").get<Types::Trytes>();
+  if (res.has("trunkTransaction")) {
+    trunkTransaction_ = res.getString("trunkTransaction");
   }
 
-  if (res.count("branchTransaction")) {
-    branchTransaction_ = res.at("branchTransaction").get<Types::Trytes>();
+  if (res.has("branchTransaction")) {
+    branchTransaction_ = res.getString("branchTransaction");
   }
 }
 
diff --git a/source/api/responses/get_trytes.cpp b/source/api/responses/get_trytes.cpp
index 2fdddfd..7051fc0 100644
--- a/source/api/responses/get_trytes.cpp
+++ b/source/api/responses/get_trytes.cpp
@@ -34,16 +34,16 @@ namespace Responses {
 GetTrytes::GetTrytes(const std::vector<Types::Trytes>& trytes) : trytes_(trytes) {
 }
 
-GetTrytes::GetTrytes(const json& res) {
+GetTrytes::GetTrytes(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-GetTrytes::deserialize(const json& res) {
+GetTrytes::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("trytes")) {
-    trytes_ = res.at("trytes").get<std::vector<Types::Trytes>>();
+  if (res.has("trytes")) {
+    trytes_ = res.getStringVector("trytes");
   }
 }
 
diff --git a/source/api/responses/remove_neighbors.cpp b/source/api/responses/remove_neighbors.cpp
index 9e15cbf..d697abc 100644
--- a/source/api/responses/remove_neighbors.cpp
+++ b/source/api/responses/remove_neighbors.cpp
@@ -35,16 +35,16 @@ RemoveNeighbors::RemoveNeighbors(const int64_t& removedNeighbors)
     : removedNeighbors_(removedNeighbors) {
 }
 
-RemoveNeighbors::RemoveNeighbors(const json& res) {
+RemoveNeighbors::RemoveNeighbors(const Utils::json& res) {
   deserialize(res);
 }
 
 void
-RemoveNeighbors::deserialize(const json& res) {
+RemoveNeighbors::deserialize(const Utils::json& res) {
   Base::deserialize(res);
 
-  if (res.count("removedNeighbors")) {
-    removedNeighbors_ = res.at("removedNeighbors").get<int64_t>();
+  if (res.has("removedNeighbors")) {
+    removedNeighbors_ = res.getInt("removedNeighbors");
   }
 }
 
diff --git a/source/utils/json.cpp b/source/utils/json.cpp
new file mode 100644
index 0000000..2c14daf
--- /dev/null
+++ b/source/utils/json.cpp
@@ -0,0 +1,159 @@
+//
+// MIT License
+//
+// Copyright (c) 2017-2018 Thibault Martinez and Simon Ninon
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+//
+
+#include <iota/utils/json.hpp>
+
+namespace IOTA {
+
+namespace Utils {
+
+rapidjson::MemoryPoolAllocator<> json::memory_pool_;
+
+json::json(void) : json_(rapidjson::kObjectType, &memory_pool_) {
+}
+
+json::json(const rapidjson::Value& val) : json_(rapidjson::kObjectType, &memory_pool_) {
+  json_.CopyFrom(val, memory_pool_);
+}
+
+void
+json::loads(const std::string& json_str) {
+  json_.Parse(json_str.c_str());
+}
+
+std::string
+json::dumps(void) const {
+  rapidjson::StringBuffer                    buffer;
+  rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
+  json_.Accept(writer);
+
+  return buffer.GetString();
+}
+
+bool
+json::has(const std::string& key) const {
+  return json_.HasMember(key.data());
+}
+
+void
+json::set(const std::string& key, int64_t value) {
+  auto key_val = rapidjson::Value{ key.data(), memory_pool_ };
+
+  json_.AddMember(key_val.Move(), value, memory_pool_);
+}
+
+void
+json::set(const std::string& key, const std::string& value) {
+  auto val     = rapidjson::Value(value.data(), memory_pool_);
+  auto key_val = rapidjson::Value{ key.data(), memory_pool_ };
+
+  json_.AddMember(key_val.Move(), val.Move(), memory_pool_);
+}
+
+void
+json::set(const std::string& key, const std::vector<std::string>& value) {
+  auto arr     = rapidjson::Value{ rapidjson::kArrayType };
+  auto key_val = rapidjson::Value{ key.data(), memory_pool_ };
+
+  for (const auto& val : value) {
+    arr.PushBack(rapidjson::Value(val.data(), memory_pool_).Move(), memory_pool_);
+  }
+
+  json_.AddMember(key_val.Move(), arr.Move(), memory_pool_);
+}
+
+void
+json::set(const std::string& key, const std::vector<bool>& value) {
+  auto arr     = rapidjson::Value{ rapidjson::kArrayType };
+  auto key_val = rapidjson::Value{ key.data(), memory_pool_ };
+
+  for (const auto& val : value) {
+    arr.PushBack(val, memory_pool_);
+  }
+
+  json_.AddMember(key_val.Move(), arr.Move(), memory_pool_);
+}
+
+void
+json::set(const std::string& key, std::vector<json>& value) {
+  auto arr     = rapidjson::Value{ rapidjson::kArrayType };
+  auto key_val = rapidjson::Value{ key.data(), memory_pool_ };
+
+  for (auto& val : value) {
+    arr.PushBack(val.json_, memory_pool_);
+  }
+
+  json_.AddMember(key_val.Move(), arr.Move(), memory_pool_);
+}
+
+int64_t
+json::getInt(const std::string& key) const {
+  return json_[key.data()].GetInt64();
+}
+
+std::string
+json::getString(const std::string& key) const {
+  return json_[key.data()].GetString();
+}
+
+std::vector<std::string>
+json::getStringVector(const std::string& key) const {
+  auto arr = json_[key.data()].GetArray();
+
+  std::vector<std::string> res;
+  for (auto it = arr.Begin(); it != arr.End(); ++it) {
+    res.push_back(it->GetString());
+  }
+
+  return res;
+}
+
+std::vector<bool>
+json::getBoolVector(const std::string& key) const {
+  auto arr = json_[key.data()].GetArray();
+
+  std::vector<bool> res;
+  for (auto it = arr.Begin(); it != arr.End(); ++it) {
+    res.push_back(it->GetBool());
+  }
+
+  return res;
+}
+
+std::vector<json>
+json::getJsonVector(const std::string& key) const {
+  auto arr = json_[key.data()].GetArray();
+
+  std::vector<json> res;
+  for (auto it = arr.Begin(); it != arr.End(); ++it) {
+    res.push_back(json(*it));
+  }
+
+  return res;
+}
+
+}  // namespace Utils
+
+}  // namespace IOTA
diff --git a/test.cpp b/test.cpp
new file mode 100644
index 0000000..0b45369
--- /dev/null
+++ b/test.cpp
@@ -0,0 +1,25 @@
+#include <iostream>
+#include <iota/iota>
+
+static std::string proxy_host = "localhost";
+static uint16_t    proxy_port = 14265;
+
+const std::string&
+get_proxy_host(void) {
+  return proxy_host;
+}
+
+const uint16_t&
+get_proxy_port(void) {
+  return proxy_port;
+}
+
+int
+main() {
+  IOTA::API::Core api(get_proxy_host(), get_proxy_port());
+
+  for (int i = 0; i < 1000; ++i) {
+    api.getNodeInfo();
+    api.addNeighbors({ "udp://8.8.8.8:14265", "udp://8.8.8.5:14265" });
+  }
+}
diff --git a/test/source/api/requests/add_neighbors_test.cpp b/test/source/api/requests/add_neighbors_test.cpp
index 15e5e2c..704a49c 100644
--- a/test/source/api/requests/add_neighbors_test.cpp
+++ b/test/source/api/requests/add_neighbors_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/add_neighbors.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(AddNeighborsRequest, CtorShouldInitFields) {
   const IOTA::API::Requests::AddNeighbors req{ { "uri1", "uri2" } };
@@ -51,10 +52,10 @@ TEST(AddNeighborsRequest, SetUris) {
 
 TEST(AddNeighborsRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::AddNeighbors req{ { "uri1", "uri2" } };
-  json                                    data;
+  IOTA::Utils::json                       data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "addNeighbors");
-  EXPECT_EQ(data["uris"], std::vector<std::string>({ "uri1", "uri2" }));
+  EXPECT_EQ(data.getString("command"), "addNeighbors");
+  EXPECT_EQ(data.getStringVector("uris"), std::vector<std::string>({ "uri1", "uri2" }));
 }
diff --git a/test/source/api/requests/attach_to_tangle_test.cpp b/test/source/api/requests/attach_to_tangle_test.cpp
index 75f0ffb..d973832 100644
--- a/test/source/api/requests/attach_to_tangle_test.cpp
+++ b/test/source/api/requests/attach_to_tangle_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/attach_to_tangle.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(AttachToTangleRequest, CtorShouldInitFields) {
   const IOTA::API::Requests::AttachToTangle req{ "trunk", "branch", 42, { "trytes1", "trytes2" } };
@@ -93,13 +94,14 @@ TEST(AttachToTangleRequest, setTrytes) {
 
 TEST(AttachToTangleRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::AttachToTangle req{ "trunk", "branch", 42, { "trytes1", "trytes2" } };
-  json                                      data;
+  IOTA::Utils::json                         data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "attachToTangle");
-  EXPECT_EQ(data["trunkTransaction"], "trunk");
-  EXPECT_EQ(data["branchTransaction"], "branch");
-  EXPECT_EQ(data["minWeightMagnitude"], 42);
-  EXPECT_EQ(data["trytes"], std::vector<IOTA::Types::Trytes>({ "trytes1", "trytes2" }));
+  EXPECT_EQ(data.getString("command"), "attachToTangle");
+  EXPECT_EQ(data.getString("trunkTransaction"), "trunk");
+  EXPECT_EQ(data.getString("branchTransaction"), "branch");
+  EXPECT_EQ(data.getInt("minWeightMagnitude"), 42);
+  EXPECT_EQ(data.getStringVector("trytes"),
+            std::vector<IOTA::Types::Trytes>({ "trytes1", "trytes2" }));
 }
diff --git a/test/source/api/requests/base_test.cpp b/test/source/api/requests/base_test.cpp
index e01a3d7..80d9745 100644
--- a/test/source/api/requests/base_test.cpp
+++ b/test/source/api/requests/base_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/base.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(BaseRequest, CtorShouldInitFields) {
   const IOTA::API::Requests::Base req{ { "cmd" } };
@@ -35,9 +36,9 @@ TEST(BaseRequest, CtorShouldInitFields) {
 
 TEST(BaseRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::Base req{ "cmd" };
-  json                            data;
+  IOTA::Utils::json               data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "cmd");
+  EXPECT_EQ(data.getString("command"), "cmd");
 }
diff --git a/test/source/api/requests/broadcast_transactions_test.cpp b/test/source/api/requests/broadcast_transactions_test.cpp
index abe7c06..865e3b4 100644
--- a/test/source/api/requests/broadcast_transactions_test.cpp
+++ b/test/source/api/requests/broadcast_transactions_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/broadcast_transactions.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(BroadcastTransactionsRequest, CtorShouldInitFields) {
   const IOTA::API::Requests::BroadcastTransactions res{ { "TESTA", "TESTB" } };
@@ -54,10 +55,9 @@ TEST(BroadcastTransactionsRequest, SetTrytes) {
 TEST(BroadcastTransactionsRequest, Serialize) {
   const IOTA::API::Requests::BroadcastTransactions res{ { "TESTA", "TESTB" } };
 
-  json data;
+  IOTA::Utils::json data;
   res.serialize(data);
 
-  EXPECT_EQ(data["command"], "broadcastTransactions");
-  EXPECT_EQ(data["trytes"].get<std::vector<std::string>>(),
-            std::vector<IOTA::Types::Trytes>({ "TESTA", "TESTB" }));
+  EXPECT_EQ(data.getString("command"), "broadcastTransactions");
+  EXPECT_EQ(data.getStringVector("trytes"), std::vector<IOTA::Types::Trytes>({ "TESTA", "TESTB" }));
 }
diff --git a/test/source/api/requests/find_transactions_test.cpp b/test/source/api/requests/find_transactions_test.cpp
index aecdf28..1d84af5 100644
--- a/test/source/api/requests/find_transactions_test.cpp
+++ b/test/source/api/requests/find_transactions_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/find_transactions.hpp>
+#include <iota/utils/json.hpp>
 #include <test/utils/constants.hpp>
 
 TEST(FindTransactionsRequest, CtorShouldInitFields) {
@@ -173,16 +174,19 @@ TEST(FindTransactionsRequest, SerializeShouldInitJson) {
                                                    { { "TAGONE" }, { "TAGTWO" } },
                                                    { "approvee1", "approvee2" },
                                                    { "bundle1", "bundle2" } };
-  json                                        data;
+  IOTA::Utils::json                           data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "findTransactions");
-  EXPECT_EQ(data["addresses"],
+  EXPECT_EQ(data.getString("command"), "findTransactions");
+  EXPECT_EQ(data.getStringVector("addresses"),
             std::vector<IOTA::Types::Trytes>({ ACCOUNT_1_ADDRESS_1_HASH_WITHOUT_CHECKSUM,
                                                ACCOUNT_1_ADDRESS_2_HASH_WITHOUT_CHECKSUM }));
-  EXPECT_EQ(data["tags"], std::vector<IOTA::Types::Trytes>(
-                              { "TAGONE999999999999999999999", "TAGTWO999999999999999999999" }));
-  EXPECT_EQ(data["approvees"], std::vector<IOTA::Types::Trytes>({ "approvee1", "approvee2" }));
-  EXPECT_EQ(data["bundles"], std::vector<IOTA::Types::Trytes>({ "bundle1", "bundle2" }));
+  EXPECT_EQ(data.getStringVector("tags"),
+            std::vector<IOTA::Types::Trytes>(
+                { "TAGONE999999999999999999999", "TAGTWO999999999999999999999" }));
+  EXPECT_EQ(data.getStringVector("approvees"),
+            std::vector<IOTA::Types::Trytes>({ "approvee1", "approvee2" }));
+  EXPECT_EQ(data.getStringVector("bundles"),
+            std::vector<IOTA::Types::Trytes>({ "bundle1", "bundle2" }));
 }
diff --git a/test/source/api/requests/get_balances_test.cpp b/test/source/api/requests/get_balances_test.cpp
index 004413d..ce904c1 100644
--- a/test/source/api/requests/get_balances_test.cpp
+++ b/test/source/api/requests/get_balances_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/get_balances.hpp>
+#include <iota/utils/json.hpp>
 #include <test/utils/constants.hpp>
 
 TEST(GetBalancesRequest, DefaultCtorShouldInitFields) {
@@ -83,13 +84,13 @@ TEST(GetBalancesRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::GetBalances req{
     { ACCOUNT_1_ADDRESS_1_HASH, ACCOUNT_1_ADDRESS_2_HASH }, 42
   };
-  json data;
+  IOTA::Utils::json data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "getBalances");
-  EXPECT_EQ(data["addresses"],
+  EXPECT_EQ(data.getString("command"), "getBalances");
+  EXPECT_EQ(data.getStringVector("addresses"),
             std::vector<IOTA::Types::Trytes>({ ACCOUNT_1_ADDRESS_1_HASH_WITHOUT_CHECKSUM,
                                                ACCOUNT_1_ADDRESS_2_HASH_WITHOUT_CHECKSUM }));
-  EXPECT_EQ(data["threshold"], 42);
+  EXPECT_EQ(data.getInt("threshold"), 42);
 }
diff --git a/test/source/api/requests/get_inclusion_states_test.cpp b/test/source/api/requests/get_inclusion_states_test.cpp
index 47e53c3..43a5271 100644
--- a/test/source/api/requests/get_inclusion_states_test.cpp
+++ b/test/source/api/requests/get_inclusion_states_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/get_inclusion_states.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetInclusionStatesRequest, CtorShouldInitFields) {
   const IOTA::API::Requests::GetInclusionStates req(
@@ -74,11 +75,12 @@ TEST(GetInclusionStatesRequest, SetTips) {
 
 TEST(GetInclusionStatesRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::GetInclusionStates req{ { "tx1", "tx2" }, { "tip1", "tip2" } };
-  json                                          data;
+  IOTA::Utils::json                             data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "getInclusionStates");
-  EXPECT_EQ(data["transactions"], std::vector<IOTA::Types::Trytes>({ "tx1", "tx2" }));
-  EXPECT_EQ(data["tips"], std::vector<IOTA::Types::Trytes>({ "tip1", "tip2" }));
+  EXPECT_EQ(data.getString("command"), "getInclusionStates");
+  EXPECT_EQ(data.getStringVector("transactions"),
+            std::vector<IOTA::Types::Trytes>({ "tx1", "tx2" }));
+  EXPECT_EQ(data.getStringVector("tips"), std::vector<IOTA::Types::Trytes>({ "tip1", "tip2" }));
 }
diff --git a/test/source/api/requests/get_neighbors_test.cpp b/test/source/api/requests/get_neighbors_test.cpp
index e79ea71..86f76cb 100644
--- a/test/source/api/requests/get_neighbors_test.cpp
+++ b/test/source/api/requests/get_neighbors_test.cpp
@@ -26,12 +26,13 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/get_neighbors.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetNeighborsRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::GetNeighbors req;
-  json                                    data;
+  IOTA::Utils::json                       data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "getNeighbors");
+  EXPECT_EQ(data.getString("command"), "getNeighbors");
 }
diff --git a/test/source/api/requests/get_node_info_test.cpp b/test/source/api/requests/get_node_info_test.cpp
index d5aa487..5ea5ba8 100644
--- a/test/source/api/requests/get_node_info_test.cpp
+++ b/test/source/api/requests/get_node_info_test.cpp
@@ -26,12 +26,13 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/get_node_info.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetNodeInfoRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::GetNodeInfo req;
-  json                                   data;
+  IOTA::Utils::json                      data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "getNodeInfo");
+  EXPECT_EQ(data.getString("command"), "getNodeInfo");
 }
diff --git a/test/source/api/requests/get_tips_test.cpp b/test/source/api/requests/get_tips_test.cpp
index 30e453e..5c769e8 100644
--- a/test/source/api/requests/get_tips_test.cpp
+++ b/test/source/api/requests/get_tips_test.cpp
@@ -26,12 +26,13 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/get_tips.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetTipsRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::GetTips req;
-  json                               data;
+  IOTA::Utils::json                  data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "getTips");
+  EXPECT_EQ(data.getString("command"), "getTips");
 }
diff --git a/test/source/api/requests/get_transactions_to_approve_test.cpp b/test/source/api/requests/get_transactions_to_approve_test.cpp
index acd8804..d4c3dfa 100644
--- a/test/source/api/requests/get_transactions_to_approve_test.cpp
+++ b/test/source/api/requests/get_transactions_to_approve_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/get_transactions_to_approve.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetTransactionToApproveRequest, Ctor) {
   const IOTA::API::Requests::GetTransactionsToApprove req{};
@@ -49,10 +50,10 @@ TEST(GetTransactionToApproveRequest, SetDepth) {
 
 TEST(GetTransactionToApproveRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::GetTransactionsToApprove req{ 42 };
-  json                                                data;
+  IOTA::Utils::json                                   data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "getTransactionsToApprove");
-  EXPECT_EQ(data["depth"], 42);
+  EXPECT_EQ(data.getString("command"), "getTransactionsToApprove");
+  EXPECT_EQ(data.getInt("depth"), 42);
 }
diff --git a/test/source/api/requests/get_trytes_test.cpp b/test/source/api/requests/get_trytes_test.cpp
index 99d23eb..3802d57 100644
--- a/test/source/api/requests/get_trytes_test.cpp
+++ b/test/source/api/requests/get_trytes_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/get_trytes.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetTrytesRequest, CtorShouldInitFields) {
   const IOTA::API::Requests::GetTrytes req{ { "TESTA", "TESTB" } };
@@ -53,10 +54,10 @@ TEST(GetTrytesRequest, SetHashes) {
 
 TEST(GetTrytesRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::GetTrytes req{ { "TESTA", "TESTB" } };
-  json                                 data;
+  IOTA::Utils::json                    data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "getTrytes");
-  EXPECT_EQ(data["hashes"], std::vector<IOTA::Types::Trytes>({ "TESTA", "TESTB" }));
+  EXPECT_EQ(data.getString("command"), "getTrytes");
+  EXPECT_EQ(data.getStringVector("hashes"), std::vector<IOTA::Types::Trytes>({ "TESTA", "TESTB" }));
 }
diff --git a/test/source/api/requests/interrupt_attaching_to_tangle_test.cpp b/test/source/api/requests/interrupt_attaching_to_tangle_test.cpp
index 8a7f6c0..4715694 100644
--- a/test/source/api/requests/interrupt_attaching_to_tangle_test.cpp
+++ b/test/source/api/requests/interrupt_attaching_to_tangle_test.cpp
@@ -26,12 +26,13 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/interrupt_attaching_to_tangle.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(InterruptAttachingToTangleRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::InterruptAttachingToTangle req;
-  json                                                  data;
+  IOTA::Utils::json                                     data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "interruptAttachingToTangle");
+  EXPECT_EQ(data.getString("command"), "interruptAttachingToTangle");
 }
diff --git a/test/source/api/requests/remove_neighbors_test.cpp b/test/source/api/requests/remove_neighbors_test.cpp
index fd59390..797b14b 100644
--- a/test/source/api/requests/remove_neighbors_test.cpp
+++ b/test/source/api/requests/remove_neighbors_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/remove_neighbors.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(RemoveNeighborsRequest, CtorShouldInitFields) {
   const IOTA::API::Requests::RemoveNeighbors req{ { "uri1", "uri2" } };
@@ -51,10 +52,10 @@ TEST(RemoveNeighborsRequest, SetUris) {
 
 TEST(RemoveNeighborsRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::RemoveNeighbors req{ { "uri1", "uri2" } };
-  json                                       data;
+  IOTA::Utils::json                          data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"], "removeNeighbors");
-  EXPECT_EQ(data["uris"], std::vector<std::string>({ "uri1", "uri2" }));
+  EXPECT_EQ(data.getString("command"), "removeNeighbors");
+  EXPECT_EQ(data.getStringVector("uris"), std::vector<std::string>({ "uri1", "uri2" }));
 }
diff --git a/test/source/api/requests/store_transactions_test.cpp b/test/source/api/requests/store_transactions_test.cpp
index 55b6bf7..97742f7 100644
--- a/test/source/api/requests/store_transactions_test.cpp
+++ b/test/source/api/requests/store_transactions_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/requests/store_transactions.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(StoreTransactionsRequest, CtorShouldInitFields) {
   const IOTA::API::Requests::StoreTransactions res{ { "TESTA", "TESTB" } };
@@ -53,10 +54,10 @@ TEST(StoreTransactionsRequest, SetTrytes) {
 
 TEST(StoreTransactionsRequest, SerializeShouldInitJson) {
   const IOTA::API::Requests::StoreTransactions req{ { "TESTA", "TESTB" } };
-  json                                         data;
+  IOTA::Utils::json                            data;
 
   req.serialize(data);
 
-  EXPECT_EQ(data["command"].get<std::string>(), "storeTransactions");
-  EXPECT_EQ(data["trytes"], std::vector<IOTA::Types::Trytes>({ "TESTA", "TESTB" }));
+  EXPECT_EQ(data.getString("command"), "storeTransactions");
+  EXPECT_EQ(data.getStringVector("trytes"), std::vector<IOTA::Types::Trytes>({ "TESTA", "TESTB" }));
 }
diff --git a/test/source/api/responses/add_neighbors_test.cpp b/test/source/api/responses/add_neighbors_test.cpp
index fc7a238..75eec19 100644
--- a/test/source/api/responses/add_neighbors_test.cpp
+++ b/test/source/api/responses/add_neighbors_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/add_neighbors.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(AddNeighborsResponse, CtorShouldInitFields) {
   const IOTA::API::Responses::AddNeighbors res{ 42 };
@@ -45,9 +46,9 @@ TEST(AddNeighborsResponse, SetAddedNeighbors) {
 
 TEST(AddNeighborsResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::AddNeighbors res;
-  json                               data;
+  IOTA::Utils::json                  data;
 
-  data["addedNeighbors"] = 42;
+  data.set("addedNeighbors", 42);
   res.deserialize(data);
   EXPECT_EQ(res.getAddedNeighbors(), 42);
 }
diff --git a/test/source/api/responses/attach_to_tangle_test.cpp b/test/source/api/responses/attach_to_tangle_test.cpp
index 2a78668..ec8e0a9 100644
--- a/test/source/api/responses/attach_to_tangle_test.cpp
+++ b/test/source/api/responses/attach_to_tangle_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/attach_to_tangle.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(AttachToTangleResponse, CtorShouldInitFields) {
   const IOTA::API::Responses::AttachToTangle res{ std::vector<IOTA::Types::Trytes>(
@@ -57,11 +58,11 @@ TEST(AttachToTangleResponse, SetTrytes) {
 
 TEST(AttachToTangleResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::AttachToTangle res;
-  json                                 data;
+  IOTA::Utils::json                    data;
   std::vector<IOTA::Types::Trytes>     trytes;
 
   trytes.push_back("TEST");
-  data["trytes"] = trytes;
+  data.set("trytes", trytes);
   res.deserialize(data);
   EXPECT_EQ(res.getTrytes(), trytes);
 }
diff --git a/test/source/api/responses/base_test.cpp b/test/source/api/responses/base_test.cpp
index 59fe627..1ae3a84 100644
--- a/test/source/api/responses/base_test.cpp
+++ b/test/source/api/responses/base_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/base.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(BaseResponse, CtorShouldInitFields) {
   const IOTA::API::Responses::Base res{ 0 };
@@ -43,9 +44,9 @@ TEST(BaseResponse, SetDuration) {
 
 TEST(BaseResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::Base res;
-  json                       data;
+  IOTA::Utils::json          data;
 
-  data["duration"] = 42;
+  data.set("duration", 42);
   res.deserialize(data);
   EXPECT_EQ(res.getDuration(), 42);
 }
diff --git a/test/source/api/responses/find_transactions_test.cpp b/test/source/api/responses/find_transactions_test.cpp
index 46ceac7..c18411a 100644
--- a/test/source/api/responses/find_transactions_test.cpp
+++ b/test/source/api/responses/find_transactions_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/find_transactions.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(FindTransactionsResponse, DefaultCtorShouldInitFields) {
   const IOTA::API::Responses::FindTransactions res;
@@ -74,11 +75,11 @@ TEST(FindTransactionsResponse, SetHashes) {
 
 TEST(FindTransactionsResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::FindTransactions res;
-  json                                   data;
+  IOTA::Utils::json                      data;
   std::vector<IOTA::Types::Trytes>       hashes;
 
   hashes.push_back("TEST");
-  data["hashes"] = hashes;
+  data.set("hashes", hashes);
   res.deserialize(data);
   EXPECT_EQ(res.getHashes(), hashes);
 }
diff --git a/test/source/api/responses/get_balances_test.cpp b/test/source/api/responses/get_balances_test.cpp
index 83b34a3..d4a0ad9 100644
--- a/test/source/api/responses/get_balances_test.cpp
+++ b/test/source/api/responses/get_balances_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/get_balances.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetBalancesReponse, DefaultCtorShouldInitFields) {
   const IOTA::API::Responses::GetBalances res;
@@ -102,11 +103,11 @@ TEST(GetBalancesReponse, SetMilestoneIndex) {
 
 TEST(GetBalancesReponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::GetBalances res;
-  json                              data;
+  IOTA::Utils::json                 data;
 
-  data["balances"]       = std::vector<std::string>({ "bal1", "bal2", "bal3" });
-  data["milestone"]      = "milestone";
-  data["milestoneIndex"] = 1;
+  data.set("balances", std::vector<std::string>({ "bal1", "bal2", "bal3" }));
+  data.set("milestone", "milestone");
+  data.set("milestoneIndex", 1);
 
   res.deserialize(data);
 
diff --git a/test/source/api/responses/get_inclusion_states_test.cpp b/test/source/api/responses/get_inclusion_states_test.cpp
index f6bef7b..165fa47 100644
--- a/test/source/api/responses/get_inclusion_states_test.cpp
+++ b/test/source/api/responses/get_inclusion_states_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/get_inclusion_states.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetInclusionStatesResponse, CtorShouldInitFields) {
   const IOTA::API::Responses::GetInclusionStates res{ std::vector<bool>({ true, false, true }) };
@@ -47,11 +48,11 @@ TEST(GetInclusionStatesResponse, SetStates) {
 
 TEST(GetInclusionStatesResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::GetInclusionStates res;
-  json                                     data;
+  IOTA::Utils::json                        data;
   std::vector<bool>                        states;
 
-  states.push_back("TEST");
-  data["states"] = states;
+  states.push_back(true);
+  data.set("states", states);
   res.deserialize(data);
   EXPECT_EQ(res.getStates(), states);
 }
diff --git a/test/source/api/responses/get_neighbors_test.cpp b/test/source/api/responses/get_neighbors_test.cpp
index 4d1028e..fedcf98 100644
--- a/test/source/api/responses/get_neighbors_test.cpp
+++ b/test/source/api/responses/get_neighbors_test.cpp
@@ -27,6 +27,7 @@
 
 #include <iota/api/responses/get_neighbors.hpp>
 #include <iota/models/neighbor.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetNeighborsResponse, CtorShouldInitFields) {
   const IOTA::API::Responses::GetNeighbors res{ std::vector<IOTA::Models::Neighbor>(
@@ -79,14 +80,14 @@ TEST(GetNeighborsResponse, SetNeighbors) {
 
 TEST(GetNeighborsResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::GetNeighbors res;
-  json                               data;
-  json                               neighbor;
-
-  neighbor["address"]                     = "addr1";
-  neighbor["numberOfAllTransactions"]     = 1;
-  neighbor["numberOfInvalidTransactions"] = 2;
-  neighbor["numberOfNewTransactions"]     = 3;
-  data["neighbors"]                       = std::vector<json>{ neighbor };
+  IOTA::Utils::json                  data;
+  IOTA::Utils::json                  neighbor;
+
+  neighbor.set("address", "addr1");
+  neighbor.set("numberOfAllTransactions", 1);
+  neighbor.set("numberOfInvalidTransactions", 2);
+  neighbor.set("numberOfNewTransactions", 3);
+  data.set("neighbors", std::vector<IOTA::Utils::json>{ neighbor });
 
   res.deserialize(data);
 
diff --git a/test/source/api/responses/get_node_info_test.cpp b/test/source/api/responses/get_node_info_test.cpp
index 1eeb993..dcecc14 100644
--- a/test/source/api/responses/get_node_info_test.cpp
+++ b/test/source/api/responses/get_node_info_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/get_node_info.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetNodeInfoResponse, CtorShouldInitFields) {
   const IOTA::API::Responses::GetNodeInfo res{
@@ -443,23 +444,23 @@ TEST(GetNodeInfoResponse, SetTransactionsToRequest) {
 
 TEST(GetNodeInfoResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::GetNodeInfo res;
-  json                              data;
-
-  data["appName"]                            = "appname";
-  data["appVersion"]                         = "appversion";
-  data["jreAvailableProcessors"]             = 1;
-  data["jreFreeMemory"]                      = 2;
-  data["jreMaxMemory"]                       = 3;
-  data["jreTotalMemory"]                     = 4;
-  data["latestMilestone"]                    = "milestone";
-  data["latestMilestoneIndex"]               = 5;
-  data["latestSolidSubtangleMilestone"]      = "submilestone";
-  data["latestSolidSubtangleMilestoneIndex"] = 6;
-  data["neighbors"]                          = 7;
-  data["packetsQueueSize"]                   = 8;
-  data["time"]                               = 9;
-  data["tips"]                               = 10;
-  data["transactionsToRequest"]              = 11;
+  IOTA::Utils::json                 data;
+
+  data.set("appName", "appname");
+  data.set("appVersion", "appversion");
+  data.set("jreAvailableProcessors", 1);
+  data.set("jreFreeMemory", 2);
+  data.set("jreMaxMemory", 3);
+  data.set("jreTotalMemory", 4);
+  data.set("latestMilestone", "milestone");
+  data.set("latestMilestoneIndex", 5);
+  data.set("latestSolidSubtangleMilestone", "submilestone");
+  data.set("latestSolidSubtangleMilestoneIndex", 6);
+  data.set("neighbors", 7);
+  data.set("packetsQueueSize", 8);
+  data.set("time", 9);
+  data.set("tips", 10);
+  data.set("transactionsToRequest", 11);
 
   res.deserialize(data);
 
diff --git a/test/source/api/responses/get_tips_test.cpp b/test/source/api/responses/get_tips_test.cpp
index 2219fbc..40e6d39 100644
--- a/test/source/api/responses/get_tips_test.cpp
+++ b/test/source/api/responses/get_tips_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/get_tips.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetTipsResponse, CtorShouldInitFields) {
   const IOTA::API::Responses::GetTips res{ std::vector<IOTA::Types::Trytes>({ "TESTA", "TESTB" }) };
@@ -56,11 +57,11 @@ TEST(GetTipsResponse, SetHashes) {
 
 TEST(GetTipsResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::GetTips    res;
-  json                             data;
+  IOTA::Utils::json                data;
   std::vector<IOTA::Types::Trytes> hashes;
 
   hashes.push_back("TEST");
-  data["hashes"] = hashes;
+  data.set("hashes", hashes);
   res.deserialize(data);
   EXPECT_EQ(res.getHashes(), hashes);
 }
diff --git a/test/source/api/responses/get_transactions_to_approve_test.cpp b/test/source/api/responses/get_transactions_to_approve_test.cpp
index fca9c76..f2fb5ae 100644
--- a/test/source/api/responses/get_transactions_to_approve_test.cpp
+++ b/test/source/api/responses/get_transactions_to_approve_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/get_transactions_to_approve.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetTransactionsToApproveResponse, CtorShouldInitFields) {
   const IOTA::API::Responses::GetTransactionsToApprove res{ "TESTA", "TESTB" };
@@ -47,10 +48,10 @@ TEST(GetTransactionsToApproveResponse, Setters) {
 
 TEST(GetTransactionsToApproveResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::GetTransactionsToApprove res;
-  json                                           data;
+  IOTA::Utils::json                              data;
 
-  data["trunkTransaction"]  = "TEST1";
-  data["branchTransaction"] = "TEST2";
+  data.set("trunkTransaction", "TEST1");
+  data.set("branchTransaction", "TEST2");
   res.deserialize(data);
 
   EXPECT_EQ(res.getTrunkTransaction(), "TEST1");
diff --git a/test/source/api/responses/get_trytes_test.cpp b/test/source/api/responses/get_trytes_test.cpp
index 1676395..d5b19ed 100644
--- a/test/source/api/responses/get_trytes_test.cpp
+++ b/test/source/api/responses/get_trytes_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/get_trytes.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(GetTrytesResponse, DefaultCtorShouldInitFields) {
   const IOTA::API::Responses::GetTrytes res;
@@ -74,11 +75,11 @@ TEST(GetTrytesResponse, SetTrytes) {
 
 TEST(GetTrytesResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::GetTrytes  res;
-  json                             data;
+  IOTA::Utils::json                data;
   std::vector<IOTA::Types::Trytes> trytes;
 
   trytes.push_back("TEST");
-  data["trytes"] = trytes;
+  data.set("trytes", trytes);
   res.deserialize(data);
   EXPECT_EQ(res.getTrytes(), trytes);
 }
diff --git a/test/source/api/responses/remove_neighbors_test.cpp b/test/source/api/responses/remove_neighbors_test.cpp
index 91f6467..c1d867b 100644
--- a/test/source/api/responses/remove_neighbors_test.cpp
+++ b/test/source/api/responses/remove_neighbors_test.cpp
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include <iota/api/responses/remove_neighbors.hpp>
+#include <iota/utils/json.hpp>
 
 TEST(RemoveNeighborsResponse, DefaultCtorShouldInitFields) {
   const IOTA::API::Responses::RemoveNeighbors res{};
@@ -52,9 +53,9 @@ TEST(RemoveNeighborsResponse, SetRemovedNeighbors) {
 
 TEST(RemoveNeighborsResponse, DeserializeShouldSetFields) {
   IOTA::API::Responses::RemoveNeighbors res;
-  json                                  data;
+  IOTA::Utils::json                     data;
 
-  data["removedNeighbors"] = 42;
+  data.set("removedNeighbors", 42);
   res.deserialize(data);
   EXPECT_EQ(res.getRemovedNeighbors(), 42);
 }