diff --git a/src/components/debugger/components/JsonViewer.py b/src/components/debugger/components/JsonViewer.py
index 907d612..c9bd5d3 100644
--- a/src/components/debugger/components/JsonViewer.py
+++ b/src/components/debugger/components/JsonViewer.py
@@ -315,8 +315,6 @@ class JsonViewer(BaseComponent):
   def __hash__(self):
     return hash(self._key) if self._key is not None else super().__hash__()
   
-  
-  
   @staticmethod
   def add_quotes(value: str):
     if '"' in value and "'" in value:
diff --git a/src/components/jsonviewer/JsonViewerApp.py b/src/components/jsonviewer/JsonViewerApp.py
new file mode 100644
index 0000000..3914bac
--- /dev/null
+++ b/src/components/jsonviewer/JsonViewerApp.py
@@ -0,0 +1,18 @@
+import logging
+
+from fasthtml.fastapp import fast_app
+
+from components.jsonviewer.constants import Routes
+from core.instance_manager import debug_session, InstanceManager
+
+jsonviwer_app, rt = fast_app()
+
+logger = logging.getLogger("JsonViewer")
+
+
+@rt(Routes.Fold)
+def post(session, _id: str, node_id: str, folding: str):
+  logger.debug(f"Entering {Routes.Fold} with args {debug_session(session)}, {_id=}, {node_id=}, {folding=}")
+  instance = InstanceManager.get(session, _id)
+  instance.set_node_folding(node_id, folding)
+  return instance.render_node(node_id)
\ No newline at end of file
diff --git a/src/components/jsonviewer/__init__.py b/src/components/jsonviewer/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/components/jsonviewer/assets/__init__.py b/src/components/jsonviewer/assets/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/components/jsonviewer/assets/icons.py b/src/components/jsonviewer/assets/icons.py
new file mode 100644
index 0000000..d5e7c47
--- /dev/null
+++ b/src/components/jsonviewer/assets/icons.py
@@ -0,0 +1,27 @@
+from fastcore.basics import NotStr
+
+# Fluent CaretRight20Filled
+icon_collapsed = NotStr("""<svg name="collapsed" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 20 20">
+  <g fill="none">
+    <path d="M7 14.204a1 1 0 0 0 1.628.778l4.723-3.815a1.5 1.5 0 0 0 0-2.334L8.628 5.02A1 1 0 0 0 7 5.797v8.407z" fill="currentColor">
+    </path>
+  </g>
+</svg>""")
+
+# Fluent CaretDown20Filled
+icon_expanded = NotStr("""<svg name="expanded" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 20 20">
+  <g fill="none">
+    <path d="M5.797 7a1 1 0 0 0-.778 1.628l3.814 4.723a1.5 1.5 0 0 0 2.334 0l3.815-4.723A1 1 0 0 0 14.204 7H5.797z" fill="currentColor">
+    </path>
+  </g>
+</svg>""")
+
+icon_class = NotStr("""
+<svg name="expanded" viewBox="0 0 20 20" xmlns="http://www.w3.org/2000/svg">
+ <g fill="none" stroke="currentColor" stroke-width="1.5" >
+  <polygon points="5,2 2,8 8,8" />
+  <rect x="12" y="2" width="6" height="6"/>
+  <circle cx="5" cy="15" r="3" />
+  <polygon points="11.5,15 15,11.5 18.5,15 15,18.5" />
+  </g>
+</svg>""")
diff --git a/src/components/jsonviewer/commands.py b/src/components/jsonviewer/commands.py
new file mode 100644
index 0000000..15d7966
--- /dev/null
+++ b/src/components/jsonviewer/commands.py
@@ -0,0 +1,23 @@
+from components.jsonviewer.constants import ROUTE_ROOT, Routes
+
+
+class JsonViewerCommands:
+  def __init__(self, owner):
+    self._owner = owner
+    self._id = owner.get_id()
+  
+  def fold(self, node_id: str, folding: str):
+    return {
+        "hx-post": f"{ROUTE_ROOT}{Routes.Fold}",
+        "hx-target": f"#{node_id}",
+        "hx-swap": "outerHTML",
+        "hx-vals": f'{{"_id": "{self._id}", "node_id": "{node_id}", "folding": "{folding}"}}',
+    }
+  
+  def open_digest(self, user_id, digest):
+    return {
+        "hx-post": f"{ROUTE_ROOT}{Routes.DbEngineDigest}",
+        "hx-target": f"#{self._owner.get_owner().tabs_manager.get_id()}",
+        "hx-swap": "outerHTML",
+        "hx-vals": f'{{"_id": "{self._id}", "user_id": "{user_id}", "digest": "{digest}"}}',
+    }
\ No newline at end of file
diff --git a/src/components/jsonviewer/components/JsonViewer.py b/src/components/jsonviewer/components/JsonViewer.py
new file mode 100644
index 0000000..eec584c
--- /dev/null
+++ b/src/components/jsonviewer/components/JsonViewer.py
@@ -0,0 +1,324 @@
+from dataclasses import dataclass, field
+from typing import Any
+
+from fasthtml.components import *
+from pandas import DataFrame
+
+from components.BaseComponent import BaseComponentMultipleInstance
+from components.datagrid_new.components.DataGrid import DataGrid
+from components.jsonviewer.assets.icons import icon_expanded, icon_collapsed, icon_class
+from components.jsonviewer.commands import JsonViewerCommands
+from components.jsonviewer.constants import NODES_KEYS_TO_NOT_EXPAND, NODE_OBJECT, INDENT_SIZE, MAX_TEXT_LENGTH
+from components_helpers import apply_boundaries
+from core.serializer import TAG_OBJECT
+
+
+class FoldingMode:
+  COLLAPSE = "collapse"
+  EXPAND = "expand"
+
+
+@dataclass
+class Node:
+  value: Any
+
+
+@dataclass
+class ValueNode(Node):
+  hint: str = None
+
+
+@dataclass
+class ListNode(Node):
+  node_id: str
+  level: int
+  children: list[Node] = field(default_factory=list)
+
+
+@dataclass
+class DictNode(Node):
+  node_id: str
+  level: int
+  children: dict[str, Node] = field(default_factory=dict)
+
+
+class JsonViewerHelper:
+  class_string = f"mmt-jsonviewer-string"
+  class_bool = f"mmt-jsonviewer-bool"
+  class_number = f"mmt-jsonviewer-number"
+  class_null = f"mmt-jsonviewer-null"
+  class_digest = f"mmt-jsonviewer-digest"
+  class_object = f"mmt-jsonviewer-object"
+  class_dataframe = f"mmt-jsonviewer-dataframe"
+  
+  @staticmethod
+  def is_sha256(_value):
+    return (isinstance(_value, str) and
+            len(_value) == 64 and
+            all(c in '0123456789abcdefABCDEF' for c in _value))
+
+
+class JsonViewer(BaseComponentMultipleInstance):
+  COMPONENT_INSTANCE_ID = "Jsonviewer"
+  
+  def __init__(self, session, _id, data=None, hooks=None, key=None, boundaries=None):
+    super().__init__(session, _id)
+    self._key = key  # for comparison between two jsonviewer components
+    self.data = data
+    self._node_id = -1
+    self._boundaries = boundaries if boundaries else {"height": "600"}
+    self._commands = JsonViewerCommands(self)
+    
+    # A little explanation on how the folding / unfolding work
+    # all the nodes are either fold or unfold... except if there are not
+    # self._folding_mode keeps the current value (it's FoldingMode.COLLAPSE or FoldingMode.EXPAND
+    # self._nodes_to_track keeps track of the exceptions
+    # The idea is to minimize the memory usage
+    self._folding_mode = FoldingMode.COLLAPSE
+    self._nodes_to_track = set()  # all nodes that are expanded when _fold_mode and vice versa
+    
+    self._nodes_by_id = {}
+    
+    self.node = self._create_node(None, data)
+    
+    # hooks are used to define specific rendering
+    # They are tuple (Predicate, Element to render (eg Div))
+    self.hooks = hooks or []
+    
+    self._helper = JsonViewerHelper()
+  
+  def set_data(self, data):
+    self.data = data
+    self.node = self._create_node(None, data)
+  
+  def set_node_folding(self, node_id, folding):
+    if folding == self._folding_mode:
+      self._nodes_to_track.remove(node_id)
+    else:
+      self._nodes_to_track.add(node_id)
+  
+  def render_node(self, node_id):
+    key, node = self._nodes_by_id[node_id]
+    return self._render_node(key, node)
+  
+  def set_folding_mode(self, folding_mode):
+    self._folding_mode = folding_mode
+    self._nodes_to_track.clear()
+  
+  def get_folding_mode(self):
+    return self._folding_mode
+  
+  def open_digest(self, user_id: str, digest: str):
+    return self._owner.db_engine_headers(user_id, digest)
+  
+  def _create_node(self, key, data, level=0):
+    if isinstance(data, list):
+      node_id = self._get_next_id()
+      if level <= 1 and key not in NODES_KEYS_TO_NOT_EXPAND:
+        self._nodes_to_track.add(node_id)
+      node = ListNode(data, node_id, level)
+      self._nodes_by_id[node_id] = (key, node)
+      for index, item in enumerate(data):
+        node.children.append(self._create_node(index, item, level + 1))
+    
+    elif isinstance(data, dict):
+      node_id = self._get_next_id()
+      if level <= 1 and key not in NODES_KEYS_TO_NOT_EXPAND:
+        self._nodes_to_track.add(node_id)
+      node = DictNode(data, node_id, level)
+      self._nodes_by_id[node_id] = (key, node)
+      for key, value in data.items():
+        node.children[key] = self._create_node(key, value, level + 1)
+    
+    else:
+      if key == TAG_OBJECT:
+        hint = NODE_OBJECT
+      else:
+        hint = None
+      node = ValueNode(data, hint)
+    
+    return node
+  
+  def _must_expand(self, node):
+    if not isinstance(node, (ListNode, DictNode)):
+      return None
+    
+    if self._folding_mode == FoldingMode.COLLAPSE:
+      return node.node_id in self._nodes_to_track
+    else:
+      return node.node_id not in self._nodes_to_track
+  
+  def _mk_folding(self, node: Node, must_expand: bool | None):
+    if must_expand is None:
+      return None
+    
+    return Span(icon_expanded if must_expand else icon_collapsed,
+                cls="icon-16-inline mmt-jsonviewer-folding",
+                style=f"margin-left: -{INDENT_SIZE}px;",
+                **self._commands.fold(node.node_id, FoldingMode.COLLAPSE if must_expand else FoldingMode.EXPAND)
+                )
+  
+  def _get_next_id(self):
+    self._node_id += 1
+    return f"{self._id}-{self._node_id}"
+  
+  def _render_value(self, key, node, must_expand):
+    if must_expand is False:
+      return Span("[...]" if isinstance(node, ListNode) else "{...}",
+                  id=node.node_id,
+                  **self._commands.fold(node.node_id, FoldingMode.EXPAND))
+    
+    for predicate, renderer in self.hooks:
+      if predicate(key, node, self._helper):
+        return renderer(key, node, self._helper)
+    
+    if isinstance(node, DictNode):
+      return self._render_dict(key, node)
+    elif isinstance(node, ListNode):
+      return self._render_list(key, node)
+    else:
+      data_tooltip = None
+      htmx_params = {}
+      icon = None
+      
+      if isinstance(node.value, bool):  # order is important bool is an int in Python !
+        str_value = "true" if node.value else "false"
+        data_class = "bool"
+      elif isinstance(node.value, (int, float)):
+        str_value = str(node.value)
+        data_class = "number"
+      elif node.value is None:
+        str_value = "null"
+        data_class = "null"
+      elif self._helper.is_sha256(node.value):
+        str_value = str(node.value)
+        data_class = "digest"
+        htmx_params = self._commands.open_digest(self.user_id, node.value)
+      elif node.hint == NODE_OBJECT:
+        icon = icon_class
+        str_value = node.value.split(".")[-1]
+        data_class = "object"
+      elif isinstance(node.value, DataFrame):
+        dg = DataGrid(self._session)
+        dg.init_from_dataframe(node.value)
+        str_value = dg
+        data_class = "dataframe"
+      else:
+        as_str = str(node.value)
+        if len(as_str) > MAX_TEXT_LENGTH:
+          str_value = as_str[:MAX_TEXT_LENGTH] + "..."
+          data_tooltip = as_str
+        else:
+          str_value = as_str
+        str_value = self.add_quotes(str_value)
+        data_class = "string"
+      
+      if data_tooltip is not None:
+        cls = f"mmt-jsonviewer-{data_class} mmt-tooltip"
+      else:
+        cls = f"mmt-jsonviewer-{data_class}"
+      
+      if icon is not None:
+        return Span(Span(icon, cls="icon-16-inline mr-1"),
+                    Span(str_value, data_tooltip=data_tooltip, **htmx_params),
+                    cls=cls)
+      
+      return Span(str_value, cls=cls, data_tooltip=data_tooltip, **htmx_params)
+  
+  def _render_dict(self, key, node: DictNode):
+    return Span("{",
+                *[
+                    self._render_node(child_key, value)
+                    for child_key, value in node.children.items()
+                ],
+                Div("}"),
+                id=node.node_id)
+  
+  def _render_list(self, key, node: ListNode):
+    def _all_the_same(_key, _node):
+      if len(_node.children) == 0:
+        return False
+      
+      sample_node = _node.children[0]
+      sample_value = sample_node.value
+      
+      if sample_value is None:
+        return False
+      
+      type_ = type(sample_value)
+      if type_ in (int, float, str, bool, list, dict, ValueNode):
+        return False
+      
+      # a specific rendering is specified
+      for predicate, renderer in self.hooks:
+        if predicate(_key, sample_node, self._helper):
+          return False
+      
+      return all(type(item.value) == type_ for item in _node.children)
+    
+    def _render_as_grid(_node):
+      type_ = type(_node.children[0].value)
+      icon = icon_class
+      str_value = type_.__name__.split(".")[-1]
+      
+      data = [child.value.__dict__ for child in _node.children]
+      df = DataFrame(data)
+      dg = DataGrid(self._session)
+      dg.init_from_dataframe(df)
+      return Span(Span(Span(icon, cls="icon-16-inline mr-1"), Span(str_value), cls="mmt-jsonviewer-object"),
+                  dg,
+                  id=_node.node_id)
+    
+    def _render_as_list(_node):
+      return Span("[",
+                  *[
+                      self._render_node(index, item)
+                      for index, item in enumerate(_node.children)
+                  ],
+                  Div("]"),
+                  )
+    
+    return _render_as_grid(node) if _all_the_same(key, node) else _render_as_list(node)
+  
+  def _render_node(self, key, node):
+    must_expand = self._must_expand(node)  # to be able to update the folding when the node is updated
+    return Div(
+      
+      self._mk_folding(node, must_expand),
+      Span(f'{key} : ') if key is not None else None,
+      self._render_value(key, node, must_expand),
+      
+      style=f"margin-left: {INDENT_SIZE}px;",
+      id=node.node_id if hasattr(node, "node_id") else None,
+    )
+  
+  def __ft__(self):
+    return Div(
+      Div(self._render_node(None, self.node),
+          id=f"{self._id}-root",
+          style="margin-left: 0px;"),
+      cls="mmt-jsonviewer",
+      id=f"{self._id}",
+      **apply_boundaries(self._boundaries),
+    )
+  
+  def __eq__(self, other):
+    if type(other) is type(self):
+      return self._key is not None and self._key == other._key
+    else:
+      return False
+  
+  def __hash__(self):
+    return hash(self._key) if self._key is not None else super().__hash__()
+  
+  @staticmethod
+  def add_quotes(value: str):
+    if '"' in value and "'" in value:
+      # Value contains both double and single quotes, escape double quotes
+      return f'"{value.replace("\"", "\\\"")}"'
+    elif '"' in value:
+      # Value contains double quotes, use single quotes
+      return f"'{value}'"
+    else:
+      # Default case, use double quotes
+      return f'"{value}"'
diff --git a/src/components/jsonviewer/components/__init__.py b/src/components/jsonviewer/components/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/components/jsonviewer/constants.py b/src/components/jsonviewer/constants.py
new file mode 100644
index 0000000..c1f0e6e
--- /dev/null
+++ b/src/components/jsonviewer/constants.py
@@ -0,0 +1,10 @@
+ROUTE_ROOT = "/jsonviewer"
+
+INDENT_SIZE = 20
+MAX_TEXT_LENGTH = 50
+
+NODE_OBJECT = "Object"
+NODES_KEYS_TO_NOT_EXPAND = ["Dataframe", "__parent__"]
+
+class Routes:
+  Fold = "/fold"
diff --git a/src/components/workflows/components/WorkflowDesignerProperties.py b/src/components/workflows/components/WorkflowDesignerProperties.py
index d7db313..6993de1 100644
--- a/src/components/workflows/components/WorkflowDesignerProperties.py
+++ b/src/components/workflows/components/WorkflowDesignerProperties.py
@@ -1,8 +1,8 @@
 from fasthtml.common import *
 
 from components.BaseComponent import BaseComponent
-from components.debugger.components.JsonViewer import JsonViewer
 from components.entryselector.components.EntrySelector import EntrySelector
+from components.jsonviewer.components.JsonViewer import JsonViewer
 from components.workflows.constants import COMPONENT_TYPES, PROCESSOR_TYPES
 from components_helpers import mk_dialog_buttons
 from core.instance_manager import InstanceManager
@@ -33,15 +33,9 @@ class WorkflowDesignerProperties(BaseComponent):
                                                              hooks={
                                                                  "on_entry_selected": self.on_entry_selector_changed})
     self._input_jsonviewer: JsonViewer = InstanceManager.new(self._session,
-                                                             JsonViewer,
-                                                             owner=self,
-                                                             user_id=None,
-                                                             data=None)
+                                                             JsonViewer)
     self._output_jsonviewer: JsonViewer = InstanceManager.new(self._session,
-                                                              JsonViewer,
-                                                              owner=self,
-                                                              user_id=None,
-                                                              data=None)
+                                                              JsonViewer)
   
   def set_entry_selector_data(self, data):
     self.entry_selector.set_data(data)
diff --git a/src/main.py b/src/main.py
index ecdd6dc..0649500 100644
--- a/src/main.py
+++ b/src/main.py
@@ -147,6 +147,7 @@ register_component("main_layout", "components.drawerlayout", "DrawerLayoutApp")
 register_component("undo_redo", "components.undo_redo", "UndoRedoApp")
 register_component("tabs", "components.tabs", "TabsApp")  # before repositories
 register_component("entryselector", "components.entryselector", "EntrySelectorApp")
+register_component("jsonviewer", "components.jsonviewer", "JsonViewerApp")
 register_component("applications", "components.applications", "ApplicationsApp")
 register_component("repositories", "components.repositories", "RepositoriesApp")
 register_component("workflows", "components.workflows", "WorkflowsApp")