diff --git a/src/cript/nodes/core.py b/src/cript/nodes/core.py
index 584e1b349..0a74fa02d 100644
--- a/src/cript/nodes/core.py
+++ b/src/cript/nodes/core.py
@@ -4,7 +4,7 @@
 import re
 import uuid
 from abc import ABC
-from dataclasses import asdict, dataclass, replace
+from dataclasses import dataclass, replace
 from typing import Dict, List, Optional, Set
 
 from cript.nodes.exceptions import (
@@ -12,6 +12,7 @@
     CRIPTExtraJsonAttributes,
     CRIPTJsonSerializationError,
 )
+from cript.nodes.node_iterator import NodeIterator
 
 tolerated_extra_json = []
 
@@ -102,7 +103,7 @@ def __str__(self) -> str:
         str
             A string representation of the node.
         """
-        return str(asdict(self._json_attrs))
+        return str(self._json_attrs)
 
     @property
     def uid(self):
@@ -200,6 +201,7 @@ def _from_json(cls, json_dict: dict):
                 attrs = replace(attrs, uid="_:" + attrs.uid)
         except AttributeError:
             pass
+
         # But here we force even usually unwritable fields to be set.
         node._update_json_attrs_if_valid(attrs)
 
@@ -466,7 +468,7 @@ class ReturnTuple:
             if is_patch:
                 del tmp_dict["uuid"]  # patches do not allow UUID is the parent most node
 
-            return ReturnTuple(json.dumps(tmp_dict), tmp_dict, NodeEncoder.handled_ids)
+            return ReturnTuple(json.dumps(tmp_dict, **kwargs), tmp_dict, NodeEncoder.handled_ids)
         except Exception as exc:
             # TODO this handling that doesn't tell the user what happened and how they can fix it
             #   this just tells the user that something is wrong
@@ -600,40 +602,18 @@ def is_attr_present(node: BaseNode, key, value):
         if handled_nodes is None:
             handled_nodes = []
 
-        # Protect against cycles in graph, by handling every instance of a node only once
-        if self in handled_nodes:
-            return []
-        handled_nodes += [self]
-
         found_children = []
 
-        # In this search we include the calling node itself.
-        # We check for this node if all specified attributes are present by counting them (AND condition).
-        found_attr = 0
-        for key, value in search_attr.items():
-            if is_attr_present(self, key, value):
-                found_attr += 1
-        # If exactly all attributes are found, it matches the search criterion
-        if found_attr == len(search_attr):
-            found_children += [self]
-
-        # Recursion according to the recursion depth for all node children.
-        if search_depth != 0:
-            # Loop over all attributes, runtime contribution (none, or constant (max number of attributes of a node)
-            for field in self._json_attrs.__dataclass_fields__:
-                value = getattr(self._json_attrs, field)
-                # To save code paths, I convert non-lists into lists with one element.
-                if not isinstance(value, list):
-                    value = [value]
-                # Run time contribution: number of elements in the attribute list.
-                for v in value:
-                    try:  # Try every attribute for recursion (duck-typing)
-                        found_children += v.find_children(search_attr, search_depth - 1, handled_nodes=handled_nodes)
-                    except AttributeError:
-                        pass
-        # Total runtime, of non-recursive call: O(m*h) + O(k) where k is the number of children for this node,
-        #   h being the depth of the search dictionary, m being the number of nodes in the attribute list.
-        # Total runtime, with recursion: O(n*(k+m*h). A full graph traversal O(n) with a cost per node, that scales with the number of children per node and the search depth of the search dictionary.
+        node_iterator = NodeIterator(self, search_depth)
+        for node in node_iterator:
+            found_attr = 0
+            for key, value in search_attr.items():
+                if is_attr_present(node, key, value):
+                    found_attr += 1
+            # If exactly all attributes are found, it matches the search criterion
+            if found_attr == len(search_attr):
+                found_children += [node]
+
         return found_children
 
     def remove_child(self, child) -> bool:
diff --git a/src/cript/nodes/node_iterator.py b/src/cript/nodes/node_iterator.py
new file mode 100644
index 000000000..b99f8e231
--- /dev/null
+++ b/src/cript/nodes/node_iterator.py
@@ -0,0 +1,68 @@
+from dataclasses import fields
+from typing import Any, List, Set
+
+
+class NodeIterator:
+    def __init__(self, root, max_recursion_depth=-1):
+        self._iter_position: int = 0
+        self._uuid_visited: Set[str] = set()
+        self._stack: List[Any] = []
+        self._recursion_depth = []
+        self._max_recursion_depth = max_recursion_depth
+        self._depth_first(root, 0)
+
+    def _add_node(self, child_node, recursion_depth: int):
+        if child_node.uuid not in self._uuid_visited:
+            self._stack.append(child_node)
+            self._recursion_depth.append(recursion_depth)
+            self._uuid_visited.add(child_node.uuid)
+            return True
+        return False
+
+    def _check_recursion(self, child_node) -> bool:
+        """Helper function that adds a child to the stack.
+
+        This function can be called for both listed children and regular children attributes
+        """
+        try:
+            uuid = child_node.uuid
+        except AttributeError:
+            return False
+
+        if uuid not in self._uuid_visited:
+            return True
+        return False
+
+    def _depth_first(self, node, recursion_depth: int) -> None:
+        """Helper function that does the traversal in depth first order and stores result in stack"""
+        node_added = self._add_node(node, recursion_depth)
+        if not node_added:
+            return
+
+        if self._max_recursion_depth >= 0 and recursion_depth >= self._max_recursion_depth:
+            return
+
+        field_names = [field.name for field in fields(node._json_attrs)]
+        for attr_name in sorted(field_names):
+            attr = getattr(node._json_attrs, attr_name)
+            if not isinstance(attr, list):
+                attr = [attr]
+            for list_attr in attr:
+                if self._check_recursion(list_attr):
+                    self._depth_first(list_attr, recursion_depth + 1)
+
+    def __next__(self):
+        if self._iter_position >= len(self._stack):
+            raise StopIteration
+        self._iter_position += 1
+        return self._stack[self._iter_position - 1]
+
+    def __iter__(self):
+        self._iter_position = 0
+        return self
+
+    def __len__(self):
+        return len(self._stack)
+
+    def __getitem__(self, idx: int):
+        return self._stack[idx]
diff --git a/src/cript/nodes/primary_nodes/collection.py b/src/cript/nodes/primary_nodes/collection.py
index daa7e6278..6ae9f743c 100644
--- a/src/cript/nodes/primary_nodes/collection.py
+++ b/src/cript/nodes/primary_nodes/collection.py
@@ -1,10 +1,11 @@
 from dataclasses import dataclass, field, replace
-from typing import Any, List, Optional
+from typing import Any, List, Optional, Union
 
 from beartype import beartype
 
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
 from cript.nodes.supporting_nodes import User
+from cript.nodes.util.json import UIDProxy
 
 
 class Collection(PrimaryBaseNode):
@@ -56,17 +57,19 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
         """
 
         # TODO add proper typing in future, using Any for now to avoid circular import error
-        member: List[User] = field(default_factory=list)
-        admin: List[User] = field(default_factory=list)
-        experiment: List[Any] = field(default_factory=list)
-        inventory: List[Any] = field(default_factory=list)
+        member: List[Union[User, UIDProxy]] = field(default_factory=list)
+        admin: List[Union[User, UIDProxy]] = field(default_factory=list)
+        experiment: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        inventory: List[Union[Any, UIDProxy]] = field(default_factory=list)
         doi: str = ""
-        citation: List[Any] = field(default_factory=list)
+        citation: List[Union[Any, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
     @beartype
-    def __init__(self, name: str, experiment: Optional[List[Any]] = None, inventory: Optional[List[Any]] = None, doi: str = "", citation: Optional[List[Any]] = None, notes: str = "", **kwargs) -> None:
+    def __init__(
+        self, name: str, experiment: Optional[List[Union[Any, UIDProxy]]] = None, inventory: Optional[List[Union[Any, UIDProxy]]] = None, doi: str = "", citation: Optional[List[Union[Any, UIDProxy]]] = None, notes: str = "", **kwargs
+    ) -> None:
         """
         create a Collection with a name
         add list of experiment, inventory, citation, doi, and notes if available.
@@ -117,12 +120,12 @@ def __init__(self, name: str, experiment: Optional[List[Any]] = None, inventory:
 
     @property
     @beartype
-    def member(self) -> List[User]:
+    def member(self) -> List[Union[User, UIDProxy]]:
         return self._json_attrs.member.copy()
 
     @property
     @beartype
-    def admin(self) -> List[User]:
+    def admin(self) -> List[Union[User, UIDProxy]]:
         return self._json_attrs.admin
 
     @property
diff --git a/src/cript/nodes/primary_nodes/computation.py b/src/cript/nodes/primary_nodes/computation.py
index 87d9b317a..89b0ac437 100644
--- a/src/cript/nodes/primary_nodes/computation.py
+++ b/src/cript/nodes/primary_nodes/computation.py
@@ -1,9 +1,10 @@
 from dataclasses import dataclass, field, replace
-from typing import Any, List, Optional
+from typing import Any, List, Optional, Union
 
 from beartype import beartype
 
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
+from cript.nodes.util.json import UIDProxy
 
 
 class Computation(PrimaryBaseNode):
@@ -64,12 +65,12 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
 
         type: str = ""
         # TODO add proper typing in future, using Any for now to avoid circular import error
-        input_data: List[Any] = field(default_factory=list)
-        output_data: List[Any] = field(default_factory=list)
-        software_configuration: List[Any] = field(default_factory=list)
-        condition: List[Any] = field(default_factory=list)
-        prerequisite_computation: Optional["Computation"] = None
-        citation: List[Any] = field(default_factory=list)
+        input_data: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        output_data: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        software_configuration: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        condition: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        prerequisite_computation: Optional[Union["Computation", UIDProxy]] = None
+        citation: List[Union[Any, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
@@ -78,12 +79,12 @@ def __init__(
         self,
         name: str,
         type: str,
-        input_data: Optional[List[Any]] = None,
-        output_data: Optional[List[Any]] = None,
-        software_configuration: Optional[List[Any]] = None,
-        condition: Optional[List[Any]] = None,
-        prerequisite_computation: Optional["Computation"] = None,
-        citation: Optional[List[Any]] = None,
+        input_data: Optional[List[Union[Any, UIDProxy]]] = None,
+        output_data: Optional[List[Union[Any, UIDProxy]]] = None,
+        software_configuration: Optional[List[Union[Any, UIDProxy]]] = None,
+        condition: Optional[List[Union[Any, UIDProxy]]] = None,
+        prerequisite_computation: Optional[Union["Computation", UIDProxy]] = None,
+        citation: Optional[List[Union[Any, UIDProxy]]] = None,
         notes: str = "",
         **kwargs
     ) -> None:
@@ -364,7 +365,7 @@ def condition(self, new_condition_list: List[Any]) -> None:
 
     @property
     @beartype
-    def prerequisite_computation(self) -> Optional["Computation"]:
+    def prerequisite_computation(self) -> Optional[Union["Computation", UIDProxy]]:
         """
         prerequisite computation
 
@@ -386,7 +387,7 @@ def prerequisite_computation(self) -> Optional["Computation"]:
 
     @prerequisite_computation.setter
     @beartype
-    def prerequisite_computation(self, new_prerequisite_computation: Optional["Computation"]) -> None:
+    def prerequisite_computation(self, new_prerequisite_computation: Optional[Union["Computation", UIDProxy]]) -> None:
         """
         set new prerequisite_computation
 
diff --git a/src/cript/nodes/primary_nodes/computation_process.py b/src/cript/nodes/primary_nodes/computation_process.py
index c08f853c6..a514e898f 100644
--- a/src/cript/nodes/primary_nodes/computation_process.py
+++ b/src/cript/nodes/primary_nodes/computation_process.py
@@ -1,9 +1,10 @@
 from dataclasses import dataclass, field, replace
-from typing import Any, List, Optional
+from typing import Any, List, Optional, Union
 
 from beartype import beartype
 
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
+from cript.nodes.util.json import UIDProxy
 
 
 class ComputationProcess(PrimaryBaseNode):
@@ -113,13 +114,13 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
 
         type: str = ""
         # TODO add proper typing in future, using Any for now to avoid circular import error
-        input_data: List[Any] = field(default_factory=list)
-        output_data: List[Any] = field(default_factory=list)
-        ingredient: List[Any] = field(default_factory=list)
-        software_configuration: List[Any] = field(default_factory=list)
-        condition: List[Any] = field(default_factory=list)
-        property: List[Any] = field(default_factory=list)
-        citation: List[Any] = field(default_factory=list)
+        input_data: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        output_data: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        ingredient: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        software_configuration: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        condition: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        property: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        citation: List[Union[Any, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
@@ -128,13 +129,13 @@ def __init__(
         self,
         name: str,
         type: str,
-        input_data: List[Any],
-        ingredient: List[Any],
-        output_data: Optional[List[Any]] = None,
-        software_configuration: Optional[List[Any]] = None,
-        condition: Optional[List[Any]] = None,
-        property: Optional[List[Any]] = None,
-        citation: Optional[List[Any]] = None,
+        input_data: List[Union[Any, UIDProxy]],
+        ingredient: List[Union[Any, UIDProxy]],
+        output_data: Optional[List[Union[Any, UIDProxy]]] = None,
+        software_configuration: Optional[List[Union[Any, UIDProxy]]] = None,
+        condition: Optional[List[Union[Any, UIDProxy]]] = None,
+        property: Optional[List[Union[Any, UIDProxy]]] = None,
+        citation: Optional[List[Union[Any, UIDProxy]]] = None,
         notes: str = "",
         **kwargs
     ):
diff --git a/src/cript/nodes/primary_nodes/data.py b/src/cript/nodes/primary_nodes/data.py
index e631dd27b..ac59dc870 100644
--- a/src/cript/nodes/primary_nodes/data.py
+++ b/src/cript/nodes/primary_nodes/data.py
@@ -4,6 +4,7 @@
 from beartype import beartype
 
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
+from cript.nodes.util.json import UIDProxy
 
 
 class Data(PrimaryBaseNode):
@@ -74,13 +75,13 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
 
         type: str = ""
         # TODO add proper typing in future, using Any for now to avoid circular import error
-        file: List[Any] = field(default_factory=list)
-        sample_preparation: Any = field(default_factory=list)
-        computation: List[Any] = field(default_factory=list)
-        computation_process: Any = field(default_factory=list)
-        material: List[Any] = field(default_factory=list)
-        process: List[Any] = field(default_factory=list)
-        citation: List[Any] = field(default_factory=list)
+        file: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        sample_preparation: Union[Any, UIDProxy] = field(default_factory=list)
+        computation: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        computation_process: Union[Any, UIDProxy] = field(default_factory=list)
+        material: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        process: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        citation: List[Union[Any, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
@@ -89,13 +90,13 @@ def __init__(
         self,
         name: str,
         type: str,
-        file: List[Any],
-        sample_preparation: Any = None,
-        computation: Optional[List[Any]] = None,
-        computation_process: Optional[Any] = None,
-        material: Optional[List[Any]] = None,
-        process: Optional[List[Any]] = None,
-        citation: Optional[List[Any]] = None,
+        file: List[Union[Any, UIDProxy]],
+        sample_preparation: Union[Any, UIDProxy] = None,
+        computation: Optional[List[Union[Any, UIDProxy]]] = None,
+        computation_process: Optional[Union[Any, UIDProxy]] = None,
+        material: Optional[List[Union[Any, UIDProxy]]] = None,
+        process: Optional[List[Union[Any, UIDProxy]]] = None,
+        citation: Optional[List[Union[Any, UIDProxy]]] = None,
         notes: str = "",
         **kwargs
     ) -> None:
diff --git a/src/cript/nodes/primary_nodes/experiment.py b/src/cript/nodes/primary_nodes/experiment.py
index 4646f733a..f75ea04f9 100644
--- a/src/cript/nodes/primary_nodes/experiment.py
+++ b/src/cript/nodes/primary_nodes/experiment.py
@@ -1,9 +1,10 @@
 from dataclasses import dataclass, field, replace
-from typing import Any, List, Optional
+from typing import Any, List, Optional, Union
 
 from beartype import beartype
 
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
+from cript.nodes.util.json import UIDProxy
 
 
 class Experiment(PrimaryBaseNode):
@@ -65,12 +66,12 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
         all Collection attributes
         """
 
-        process: List[Any] = field(default_factory=list)
-        computation: List[Any] = field(default_factory=list)
-        computation_process: List[Any] = field(default_factory=list)
-        data: List[Any] = field(default_factory=list)
+        process: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        computation: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        computation_process: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        data: List[Union[Any, UIDProxy]] = field(default_factory=list)
         funding: List[str] = field(default_factory=list)
-        citation: List[Any] = field(default_factory=list)
+        citation: List[Union[Any, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
@@ -78,12 +79,12 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
     def __init__(
         self,
         name: str,
-        process: Optional[List[Any]] = None,
-        computation: Optional[List[Any]] = None,
-        computation_process: Optional[List[Any]] = None,
-        data: Optional[List[Any]] = None,
+        process: Optional[List[Union[Any, UIDProxy]]] = None,
+        computation: Optional[List[Union[Any, UIDProxy]]] = None,
+        computation_process: Optional[List[Union[Any, UIDProxy]]] = None,
+        data: Optional[List[Union[Any, UIDProxy]]] = None,
         funding: Optional[List[str]] = None,
-        citation: Optional[List[Any]] = None,
+        citation: Optional[List[Union[Any, UIDProxy]]] = None,
         notes: str = "",
         **kwargs
     ):
diff --git a/src/cript/nodes/primary_nodes/inventory.py b/src/cript/nodes/primary_nodes/inventory.py
index a0509755d..169944272 100644
--- a/src/cript/nodes/primary_nodes/inventory.py
+++ b/src/cript/nodes/primary_nodes/inventory.py
@@ -1,10 +1,11 @@
 from dataclasses import dataclass, field, replace
-from typing import List
+from typing import List, Union
 
 from beartype import beartype
 
 from cript.nodes.primary_nodes.material import Material
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
+from cript.nodes.util.json import UIDProxy
 
 
 class Inventory(PrimaryBaseNode):
@@ -59,12 +60,12 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
         all Inventory attributes
         """
 
-        material: List[Material] = field(default_factory=list)
+        material: List[Union[Material, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
     @beartype
-    def __init__(self, name: str, material: List[Material], notes: str = "", **kwargs) -> None:
+    def __init__(self, name: str, material: List[Union[Material, UIDProxy]], notes: str = "", **kwargs) -> None:
         """
         Instantiate an inventory node
 
@@ -104,7 +105,7 @@ def __init__(self, name: str, material: List[Material], notes: str = "", **kwarg
 
     @property
     @beartype
-    def material(self) -> List[Material]:
+    def material(self) -> List[Union[Material, UIDProxy]]:
         """
         List of [material](../material) in this inventory
 
@@ -131,7 +132,7 @@ def material(self) -> List[Material]:
 
     @material.setter
     @beartype
-    def material(self, new_material_list: List[Material]):
+    def material(self, new_material_list: List[Union[Material, UIDProxy]]):
         """
         set the list of material for this inventory node
 
diff --git a/src/cript/nodes/primary_nodes/material.py b/src/cript/nodes/primary_nodes/material.py
index 807711d0f..e0ae0968c 100644
--- a/src/cript/nodes/primary_nodes/material.py
+++ b/src/cript/nodes/primary_nodes/material.py
@@ -6,6 +6,7 @@
 from cript.nodes.exceptions import CRIPTMaterialIdentifierError
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
 from cript.nodes.primary_nodes.process import Process
+from cript.nodes.util.json import UIDProxy
 
 
 class Material(PrimaryBaseNode):
@@ -74,11 +75,11 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
         """
 
         # TODO add proper typing in future, using Any for now to avoid circular import error
-        component: List["Material"] = field(default_factory=list)
-        process: Optional[Process] = None
-        property: List[Any] = field(default_factory=list)
-        parent_material: Optional["Material"] = None
-        computational_forcefield: Optional[Any] = None
+        component: List[Union["Material", UIDProxy]] = field(default_factory=list)
+        process: Optional[Union[Process, UIDProxy]] = None
+        property: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        parent_material: Optional[Union["Material", UIDProxy]] = None
+        computational_forcefield: Optional[Union[Any, UIDProxy]] = None
         keyword: List[str] = field(default_factory=list)
         amino_acid: Optional[str] = None
         bigsmiles: Optional[str] = None
@@ -99,11 +100,11 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
     def __init__(
         self,
         name: str,
-        component: Optional[List["Material"]] = None,
-        process: Optional[Process] = None,
-        property: Optional[List[Any]] = None,
-        parent_material: Optional["Material"] = None,
-        computational_forcefield: Optional[Any] = None,
+        component: Optional[List[Union["Material", UIDProxy]]] = None,
+        process: Optional[Union[Process, UIDProxy]] = None,
+        property: Optional[List[Union[Any, UIDProxy]]] = None,
+        parent_material: Optional[Union["Material", UIDProxy]] = None,
+        computational_forcefield: Optional[Union[Any, UIDProxy]] = None,
         keyword: Optional[List[str]] = None,
         amino_acid: Optional[str] = None,
         bigsmiles: Optional[str] = None,
@@ -353,7 +354,7 @@ def pubchem_cid(self, new_pubchem_cid: int) -> None:
 
     @property
     @beartype
-    def component(self) -> List["Material"]:
+    def component(self) -> List[Union["Material", UIDProxy]]:
         """
         list of components ([material nodes](./)) that make up this material
 
@@ -385,7 +386,7 @@ def component(self) -> List["Material"]:
 
     @component.setter
     @beartype
-    def component(self, new_component_list: List["Material"]) -> None:
+    def component(self, new_component_list: List[Union["Material", UIDProxy]]) -> None:
         """
         set the list of component (material nodes) that make up this material
 
@@ -402,7 +403,7 @@ def component(self, new_component_list: List["Material"]) -> None:
 
     @property
     @beartype
-    def parent_material(self) -> Optional["Material"]:
+    def parent_material(self) -> Optional[Union["Material", UIDProxy]]:
         """
         List of parent materials
 
@@ -415,7 +416,7 @@ def parent_material(self) -> Optional["Material"]:
 
     @parent_material.setter
     @beartype
-    def parent_material(self, new_parent_material: Optional["Material"]) -> None:
+    def parent_material(self, new_parent_material: Optional[Union["Material", UIDProxy]]) -> None:
         """
         set the [parent materials](./) for this material
 
@@ -458,19 +459,19 @@ def computational_forcefield(self) -> Any:
 
     @computational_forcefield.setter
     @beartype
-    def computational_forcefield(self, new_computational_forcefield_list: Any) -> None:
+    def computational_forcefield(self, new_computational_forcefield: Any) -> None:
         """
         sets the list of computational forcefields for this material
 
         Parameters
         ----------
-        new_computation_forcefield_list: List[ComputationalForcefield]
+        new_computation_forcefield: ComputationalForcefield
 
         Returns
         -------
         None
         """
-        new_attrs = replace(self._json_attrs, computational_forcefield=new_computational_forcefield_list)
+        new_attrs = replace(self._json_attrs, computational_forcefield=new_computational_forcefield)
         self._update_json_attrs_if_valid(new_attrs)
 
     @property
@@ -518,11 +519,11 @@ def keyword(self, new_keyword_list: List[str]) -> None:
 
     @property
     @beartype
-    def process(self) -> Optional[Process]:
+    def process(self) -> Optional[Union[Process, UIDProxy]]:
         return self._json_attrs.process  # type: ignore
 
     @process.setter
-    def process(self, new_process: Process) -> None:
+    def process(self, new_process: Union[Process, UIDProxy]) -> None:
         new_attrs = replace(self._json_attrs, process=new_process)
         self._update_json_attrs_if_valid(new_attrs)
 
diff --git a/src/cript/nodes/primary_nodes/process.py b/src/cript/nodes/primary_nodes/process.py
index f730a14e2..56c45115a 100644
--- a/src/cript/nodes/primary_nodes/process.py
+++ b/src/cript/nodes/primary_nodes/process.py
@@ -1,9 +1,10 @@
 from dataclasses import dataclass, field, replace
-from typing import Any, List, Optional
+from typing import Any, List, Optional, Union
 
 from beartype import beartype
 
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
+from cript.nodes.util.json import UIDProxy
 
 
 class Process(PrimaryBaseNode):
@@ -61,16 +62,16 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
 
         type: str = ""
         # TODO add proper typing in future, using Any for now to avoid circular import error
-        ingredient: List[Any] = field(default_factory=list)
+        ingredient: List[Union[Any, UIDProxy]] = field(default_factory=list)
         description: str = ""
-        equipment: List[Any] = field(default_factory=list)
-        product: List[Any] = field(default_factory=list)
-        waste: List[Any] = field(default_factory=list)
-        prerequisite_process: List["Process"] = field(default_factory=list)
-        condition: List[Any] = field(default_factory=list)
-        property: List[Any] = field(default_factory=list)
+        equipment: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        product: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        waste: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        prerequisite_process: List[Union["Process", UIDProxy]] = field(default_factory=list)
+        condition: List[Union[Any, UIDProxy]] = field(default_factory=list)
+        property: List[Union[Any, UIDProxy]] = field(default_factory=list)
         keyword: List[str] = field(default_factory=list)
-        citation: List[Any] = field(default_factory=list)
+        citation: List[Union[Any, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
@@ -79,16 +80,16 @@ def __init__(
         self,
         name: str,
         type: str,
-        ingredient: Optional[List[Any]] = None,
+        ingredient: Optional[List[Union[Any, UIDProxy]]] = None,
         description: str = "",
-        equipment: Optional[List[Any]] = None,
-        product: Optional[List[Any]] = None,
-        waste: Optional[List[Any]] = None,
-        prerequisite_process: Optional[List[Any]] = None,
-        condition: Optional[List[Any]] = None,
-        property: Optional[List[Any]] = None,
+        equipment: Optional[List[Union[Any, UIDProxy]]] = None,
+        product: Optional[List[Union[Any, UIDProxy]]] = None,
+        waste: Optional[List[Union[Any, UIDProxy]]] = None,
+        prerequisite_process: Optional[List[Union["Process", UIDProxy]]] = None,
+        condition: Optional[List[Union[Any, UIDProxy]]] = None,
+        property: Optional[List[Union[Any, UIDProxy]]] = None,
         keyword: Optional[List[str]] = None,
-        citation: Optional[List[Any]] = None,
+        citation: Optional[List[Union[Any, UIDProxy]]] = None,
         notes: str = "",
         **kwargs
     ) -> None:
@@ -416,7 +417,7 @@ def waste(self, new_waste_list: List[Any]) -> None:
 
     @property
     @beartype
-    def prerequisite_process(self) -> List["Process"]:
+    def prerequisite_process(self) -> List[Union["Process", UIDProxy]]:
         """
         list of prerequisite process nodes
 
@@ -439,7 +440,7 @@ def prerequisite_process(self) -> List["Process"]:
 
     @prerequisite_process.setter
     @beartype
-    def prerequisite_process(self, new_prerequisite_process_list: List["Process"]) -> None:
+    def prerequisite_process(self, new_prerequisite_process_list: List[Union["Process", UIDProxy]]) -> None:
         """
         set the prerequisite_process for the process node
 
diff --git a/src/cript/nodes/primary_nodes/project.py b/src/cript/nodes/primary_nodes/project.py
index c644221bc..2be3056b3 100644
--- a/src/cript/nodes/primary_nodes/project.py
+++ b/src/cript/nodes/primary_nodes/project.py
@@ -1,5 +1,5 @@
 from dataclasses import dataclass, field, replace
-from typing import List, Optional
+from typing import List, Optional, Union
 
 from beartype import beartype
 
@@ -7,6 +7,7 @@
 from cript.nodes.primary_nodes.material import Material
 from cript.nodes.primary_nodes.primary_base_node import PrimaryBaseNode
 from cript.nodes.supporting_nodes import User
+from cript.nodes.util.json import UIDProxy
 
 
 class Project(PrimaryBaseNode):
@@ -59,15 +60,15 @@ class JsonAttributes(PrimaryBaseNode.JsonAttributes):
         all Project attributes
         """
 
-        member: List[User] = field(default_factory=list)
-        admin: List[User] = field(default_factory=list)
-        collection: List[Collection] = field(default_factory=list)
-        material: List[Material] = field(default_factory=list)
+        member: List[Union[User, UIDProxy]] = field(default_factory=list)
+        admin: List[Union[User, UIDProxy]] = field(default_factory=list)
+        collection: List[Union[Collection, UIDProxy]] = field(default_factory=list)
+        material: List[Union[Material, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
     @beartype
-    def __init__(self, name: str, collection: Optional[List[Collection]] = None, material: Optional[List[Material]] = None, notes: str = "", **kwargs):
+    def __init__(self, name: str, collection: Optional[List[Union[Collection, UIDProxy]]] = None, material: Optional[List[Union[Material, UIDProxy]]] = None, notes: str = "", **kwargs):
         """
         Create a Project node with Project name
 
@@ -148,17 +149,17 @@ def validate(self, api=None, is_patch=False, force_validation: bool = False):
 
     @property
     @beartype
-    def member(self) -> List[User]:
+    def member(self) -> List[Union[User, UIDProxy]]:
         return self._json_attrs.member.copy()
 
     @property
     @beartype
-    def admin(self) -> List[User]:
+    def admin(self) -> List[Union[User, UIDProxy]]:
         return self._json_attrs.admin
 
     @property
     @beartype
-    def collection(self) -> List[Collection]:
+    def collection(self) -> List[Union[Collection, UIDProxy]]:
         """
         Collection is a Project node's property that can be set during creation in the constructor
         or later by setting the project's property
@@ -179,7 +180,7 @@ def collection(self) -> List[Collection]:
 
     @collection.setter
     @beartype
-    def collection(self, new_collection: List[Collection]) -> None:
+    def collection(self, new_collection: List[Union[Collection, UIDProxy]]) -> None:
         """
         set list of collections for the project node
 
@@ -196,7 +197,7 @@ def collection(self, new_collection: List[Collection]) -> None:
 
     @property
     @beartype
-    def material(self) -> List[Material]:
+    def material(self) -> List[Union[Material, UIDProxy]]:
         """
         List of Materials that belong to this Project.
 
@@ -216,7 +217,7 @@ def material(self) -> List[Material]:
 
     @material.setter
     @beartype
-    def material(self, new_materials: List[Material]) -> None:
+    def material(self, new_materials: List[Union[Material, UIDProxy]]) -> None:
         """
         set the list of materials for this project
 
diff --git a/src/cript/nodes/subobjects/algorithm.py b/src/cript/nodes/subobjects/algorithm.py
index d45f5f894..a643d9b72 100644
--- a/src/cript/nodes/subobjects/algorithm.py
+++ b/src/cript/nodes/subobjects/algorithm.py
@@ -1,8 +1,9 @@
 from dataclasses import dataclass, field, replace
-from typing import List, Optional
+from typing import List, Optional, Union
 
 from cript.nodes.subobjects.citation import Citation
 from cript.nodes.subobjects.parameter import Parameter
+from cript.nodes.util.json import UIDProxy
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
@@ -69,12 +70,12 @@ class JsonAttributes(UUIDBaseNode.JsonAttributes):
         key: str = ""
         type: str = ""
 
-        parameter: List[Parameter] = field(default_factory=list)
-        citation: List[Citation] = field(default_factory=list)
+        parameter: List[Union[Parameter, UIDProxy]] = field(default_factory=list)
+        citation: List[Union[Citation, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
-    def __init__(self, key: str, type: str, parameter: Optional[List[Parameter]] = None, citation: Optional[List[Citation]] = None, **kwargs):  # ignored
+    def __init__(self, key: str, type: str, parameter: Optional[List[Union[Parameter, UIDProxy]]] = None, citation: Optional[List[Union[Citation, UIDProxy]]] = None, **kwargs):  # ignored
         """
         Create algorithm sub-object
 
@@ -172,7 +173,7 @@ def type(self, new_type: str) -> None:
         self._update_json_attrs_if_valid(new_attrs)
 
     @property
-    def parameter(self) -> List[Parameter]:
+    def parameter(self) -> List[Union[Parameter, UIDProxy]]:
         """
         list of [Parameter](../parameter) sub-objects for the algorithm sub-object
 
@@ -194,7 +195,7 @@ def parameter(self) -> List[Parameter]:
         return self._json_attrs.parameter.copy()
 
     @parameter.setter
-    def parameter(self, new_parameter: List[Parameter]) -> None:
+    def parameter(self, new_parameter: List[Union[Parameter, UIDProxy]]) -> None:
         """
         set a list of cript.Parameter sub-objects
 
@@ -211,7 +212,7 @@ def parameter(self, new_parameter: List[Parameter]) -> None:
         self._update_json_attrs_if_valid(new_attrs)
 
     @property
-    def citation(self) -> Citation:
+    def citation(self) -> List[Union[Citation, UIDProxy]]:
         """
         [citation](../citation) subobject for algorithm subobject
 
@@ -247,7 +248,7 @@ def citation(self) -> Citation:
         return self._json_attrs.citation.copy()  # type: ignore
 
     @citation.setter
-    def citation(self, new_citation: List[Citation]) -> None:
+    def citation(self, new_citation: List[Union[Citation, UIDProxy]]) -> None:
         """
         set the algorithm citation subobject
 
diff --git a/src/cript/nodes/subobjects/citation.py b/src/cript/nodes/subobjects/citation.py
index e4457a251..c22a33a18 100644
--- a/src/cript/nodes/subobjects/citation.py
+++ b/src/cript/nodes/subobjects/citation.py
@@ -4,6 +4,7 @@
 from beartype import beartype
 
 from cript.nodes.primary_nodes.reference import Reference
+from cript.nodes.util.json import UIDProxy
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
@@ -60,12 +61,12 @@ class Citation(UUIDBaseNode):
     @dataclass(frozen=True)
     class JsonAttributes(UUIDBaseNode.JsonAttributes):
         type: str = ""
-        reference: Optional[Reference] = None
+        reference: Optional[Union[Reference, UIDProxy]] = None
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
     @beartype
-    def __init__(self, type: str, reference: Reference, **kwargs):
+    def __init__(self, type: str, reference: Union[Reference, UIDProxy], **kwargs):
         """
         create a Citation subobject
 
@@ -164,7 +165,7 @@ def type(self, new_type: str) -> None:
 
     @property
     @beartype
-    def reference(self) -> Union[Reference, None]:
+    def reference(self) -> Union[Reference, None, UIDProxy]:
         """
         citation reference node
 
diff --git a/src/cript/nodes/subobjects/computational_forcefield.py b/src/cript/nodes/subobjects/computational_forcefield.py
index d77d38b7e..39c2b0e54 100644
--- a/src/cript/nodes/subobjects/computational_forcefield.py
+++ b/src/cript/nodes/subobjects/computational_forcefield.py
@@ -1,10 +1,11 @@
 from dataclasses import dataclass, field, replace
-from typing import List, Optional
+from typing import List, Optional, Union
 
 from beartype import beartype
 
 from cript.nodes.primary_nodes.data import Data
 from cript.nodes.subobjects.citation import Citation
+from cript.nodes.util.json import UIDProxy
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
@@ -88,13 +89,24 @@ class JsonAttributes(UUIDBaseNode.JsonAttributes):
         implicit_solvent: str = ""
         source: str = ""
         description: str = ""
-        data: List[Data] = field(default_factory=list)
-        citation: List[Citation] = field(default_factory=list)
+        data: List[Union[Data, UIDProxy]] = field(default_factory=list)
+        citation: List[Union[Citation, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
     @beartype
-    def __init__(self, key: str, building_block: str, coarse_grained_mapping: str = "", implicit_solvent: str = "", source: str = "", description: str = "", data: Optional[List[Data]] = None, citation: Optional[List[Citation]] = None, **kwargs):
+    def __init__(
+        self,
+        key: str,
+        building_block: str,
+        coarse_grained_mapping: str = "",
+        implicit_solvent: str = "",
+        source: str = "",
+        description: str = "",
+        data: Optional[List[Union[Data, UIDProxy]]] = None,
+        citation: Optional[List[Union[Citation, UIDProxy]]] = None,
+        **kwargs
+    ):
         """
         instantiate a computational_forcefield subobject
 
@@ -393,7 +405,7 @@ def description(self, new_description: str) -> None:
 
     @property
     @beartype
-    def data(self) -> List[Data]:
+    def data(self) -> List[Union[Data, UIDProxy]]:
         """
         details of mapping schema and forcefield parameters
 
@@ -426,7 +438,7 @@ def data(self) -> List[Data]:
 
     @data.setter
     @beartype
-    def data(self, new_data: List[Data]) -> None:
+    def data(self, new_data: List[Union[Data, UIDProxy]]) -> None:
         """
         set the data attribute of this computational_forcefield node
 
@@ -444,7 +456,7 @@ def data(self, new_data: List[Data]) -> None:
 
     @property
     @beartype
-    def citation(self) -> List[Citation]:
+    def citation(self) -> List[Union[Citation, UIDProxy]]:
         """
         reference to a book, paper, or scholarly work
 
@@ -483,7 +495,7 @@ def citation(self) -> List[Citation]:
 
     @citation.setter
     @beartype
-    def citation(self, new_citation: List[Citation]) -> None:
+    def citation(self, new_citation: List[Union[Citation, UIDProxy]]) -> None:
         """
         set the citation subobject of the computational_forcefield subobject
 
diff --git a/src/cript/nodes/subobjects/condition.py b/src/cript/nodes/subobjects/condition.py
index 71903857b..461952f99 100644
--- a/src/cript/nodes/subobjects/condition.py
+++ b/src/cript/nodes/subobjects/condition.py
@@ -5,6 +5,7 @@
 from beartype import beartype
 
 from cript.nodes.primary_nodes.data import Data
+from cript.nodes.util.json import UIDProxy
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
@@ -86,7 +87,7 @@ class JsonAttributes(UUIDBaseNode.JsonAttributes):
         uncertainty_type: str = ""
         set_id: Optional[int] = None
         measurement_id: Optional[int] = None
-        data: List[Data] = field(default_factory=list)
+        data: List[Union[Data, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
@@ -102,7 +103,7 @@ def __init__(
         uncertainty_type: str = "",
         set_id: Optional[int] = None,
         measurement_id: Optional[int] = None,
-        data: Optional[List[Data]] = None,
+        data: Optional[List[Union[Data, UIDProxy]]] = None,
         **kwargs
     ):
         """
@@ -504,7 +505,7 @@ def measurement_id(self, new_measurement_id: Union[int, None]) -> None:
 
     @property
     @beartype
-    def data(self) -> List[Data]:
+    def data(self) -> List[Union[Data, UIDProxy]]:
         """
         detailed data associated with the condition
 
@@ -539,7 +540,7 @@ def data(self) -> List[Data]:
 
     @data.setter
     @beartype
-    def data(self, new_data: List[Data]) -> None:
+    def data(self, new_data: List[Union[Data, UIDProxy]]) -> None:
         """
         set the data node for this Condition Subobject
 
diff --git a/src/cript/nodes/subobjects/equipment.py b/src/cript/nodes/subobjects/equipment.py
index 99fa03e2c..ecac0af21 100644
--- a/src/cript/nodes/subobjects/equipment.py
+++ b/src/cript/nodes/subobjects/equipment.py
@@ -1,11 +1,12 @@
 from dataclasses import dataclass, field, replace
-from typing import List, Union
+from typing import List, Optional, Union
 
 from beartype import beartype
 
 from cript.nodes.subobjects.citation import Citation
 from cript.nodes.subobjects.condition import Condition
 from cript.nodes.supporting_nodes.file import File
+from cript.nodes.util.json import UIDProxy
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
@@ -53,14 +54,14 @@ class Equipment(UUIDBaseNode):
     class JsonAttributes(UUIDBaseNode.JsonAttributes):
         key: str = ""
         description: str = ""
-        condition: List[Condition] = field(default_factory=list)
-        file: List[File] = field(default_factory=list)
-        citation: List[Citation] = field(default_factory=list)
+        condition: List[Union[Condition, UIDProxy]] = field(default_factory=list)
+        file: List[Union[File, UIDProxy]] = field(default_factory=list)
+        citation: List[Union[Citation, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
     @beartype
-    def __init__(self, key: str, description: str = "", condition: Union[List[Condition], None] = None, file: Union[List[File], None] = None, citation: Union[List[Citation], None] = None, **kwargs) -> None:
+    def __init__(self, key: str, description: str = "", condition: Optional[List[Union[Condition, UIDProxy]]] = None, file: Optional[List[Union[File, UIDProxy]]] = None, citation: Optional[List[Union[Citation, UIDProxy]]] = None, **kwargs) -> None:
         """
         create equipment sub-object
 
@@ -174,7 +175,7 @@ def description(self, new_description: str) -> None:
 
     @property
     @beartype
-    def condition(self) -> List[Condition]:
+    def condition(self) -> List[Union[Condition, UIDProxy]]:
         """
         conditions under which the property was measured
 
@@ -199,7 +200,7 @@ def condition(self) -> List[Condition]:
 
     @condition.setter
     @beartype
-    def condition(self, new_condition: List[Condition]) -> None:
+    def condition(self, new_condition: List[Union[Condition, UIDProxy]]) -> None:
         """
         set a list of Conditions for the equipment sub-object
 
@@ -217,7 +218,7 @@ def condition(self, new_condition: List[Condition]) -> None:
 
     @property
     @beartype
-    def file(self) -> List[File]:
+    def file(self) -> List[Union[File, UIDProxy]]:
         """
         list of file nodes to link to calibration or equipment specification documents
 
@@ -242,7 +243,7 @@ def file(self) -> List[File]:
 
     @file.setter
     @beartype
-    def file(self, new_file: List[File]) -> None:
+    def file(self, new_file: List[Union[File, UIDProxy]]) -> None:
         """
         set the file node for the equipment subobject
 
@@ -260,7 +261,7 @@ def file(self, new_file: List[File]) -> None:
 
     @property
     @beartype
-    def citation(self) -> List[Citation]:
+    def citation(self) -> List[Union[Citation, UIDProxy]]:
         """
         reference to a book, paper, or scholarly work
 
@@ -296,7 +297,7 @@ def citation(self) -> List[Citation]:
 
     @citation.setter
     @beartype
-    def citation(self, new_citation: List[Citation]) -> None:
+    def citation(self, new_citation: List[Union[Citation, UIDProxy]]) -> None:
         """
         set the citation subobject for this equipment subobject
 
diff --git a/src/cript/nodes/subobjects/ingredient.py b/src/cript/nodes/subobjects/ingredient.py
index 9c66a304c..7b58b67c5 100644
--- a/src/cript/nodes/subobjects/ingredient.py
+++ b/src/cript/nodes/subobjects/ingredient.py
@@ -5,6 +5,7 @@
 
 from cript.nodes.primary_nodes.material import Material
 from cript.nodes.subobjects.quantity import Quantity
+from cript.nodes.util.json import UIDProxy
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
@@ -65,14 +66,14 @@ class Ingredient(UUIDBaseNode):
 
     @dataclass(frozen=True)
     class JsonAttributes(UUIDBaseNode.JsonAttributes):
-        material: Optional[Material] = None
-        quantity: List[Quantity] = field(default_factory=list)
+        material: Optional[Union[Material, UIDProxy]] = None
+        quantity: List[Union[Quantity, UIDProxy]] = field(default_factory=list)
         keyword: List[str] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
     @beartype
-    def __init__(self, material: Material, quantity: List[Quantity], keyword: Optional[List[str]] = None, **kwargs):
+    def __init__(self, material: Union[Material, UIDProxy], quantity: List[Union[Quantity, UIDProxy]], keyword: Optional[List[str]] = None, **kwargs):
         """
         create an ingredient sub-object
 
@@ -117,7 +118,7 @@ def _from_json(cls, json_dict: dict):
 
     @property
     @beartype
-    def material(self) -> Union[Material, None]:
+    def material(self) -> Union[Material, None, UIDProxy]:
         """
         current material in this ingredient sub-object
 
@@ -130,7 +131,7 @@ def material(self) -> Union[Material, None]:
 
     @property
     @beartype
-    def quantity(self) -> List[Quantity]:
+    def quantity(self) -> List[Union[Quantity, UIDProxy]]:
         """
         quantity for the ingredient sub-object
 
@@ -142,7 +143,7 @@ def quantity(self) -> List[Quantity]:
         return self._json_attrs.quantity.copy()
 
     @beartype
-    def set_material(self, new_material: Material, new_quantity: List[Quantity]) -> None:
+    def set_material(self, new_material: Union[Material, UIDProxy], new_quantity: List[Union[Quantity, UIDProxy]]) -> None:
         """
         update ingredient sub-object with new material and new list of quantities
 
diff --git a/src/cript/nodes/subobjects/property.py b/src/cript/nodes/subobjects/property.py
index 196772865..d6af1a7d2 100644
--- a/src/cript/nodes/subobjects/property.py
+++ b/src/cript/nodes/subobjects/property.py
@@ -10,6 +10,7 @@
 from cript.nodes.primary_nodes.process import Process
 from cript.nodes.subobjects.citation import Citation
 from cript.nodes.subobjects.condition import Condition
+from cript.nodes.util.json import UIDProxy
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
@@ -76,14 +77,14 @@ class JsonAttributes(UUIDBaseNode.JsonAttributes):
         unit: Optional[str] = ""
         uncertainty: Optional[Number] = None
         uncertainty_type: str = ""
-        component: List[Material] = field(default_factory=list)
+        component: List[Union[Material, UIDProxy]] = field(default_factory=list)
         structure: str = ""
         method: str = ""
-        sample_preparation: Optional[Process] = None
-        condition: List[Condition] = field(default_factory=list)
-        data: List[Data] = field(default_factory=list)
-        computation: List[Computation] = field(default_factory=list)
-        citation: List[Citation] = field(default_factory=list)
+        sample_preparation: Optional[Union[Process, UIDProxy]] = None
+        condition: List[Union[Condition, UIDProxy]] = field(default_factory=list)
+        data: List[Union[Data, UIDProxy]] = field(default_factory=list)
+        computation: List[Union[Computation, UIDProxy]] = field(default_factory=list)
+        citation: List[Union[Citation, UIDProxy]] = field(default_factory=list)
         notes: str = ""
 
     _json_attrs: JsonAttributes = JsonAttributes()
@@ -97,14 +98,14 @@ def __init__(
         unit: Union[str, None],
         uncertainty: Optional[Number] = None,
         uncertainty_type: str = "",
-        component: Optional[List[Material]] = None,
+        component: Optional[List[Union[Material, UIDProxy]]] = None,
         structure: str = "",
         method: str = "",
-        sample_preparation: Optional[Process] = None,
-        condition: Optional[List[Condition]] = None,
-        data: Optional[List[Data]] = None,
-        computation: Optional[List[Computation]] = None,
-        citation: Optional[List[Citation]] = None,
+        sample_preparation: Optional[Union[Process, UIDProxy]] = None,
+        condition: Optional[List[Union[Condition, UIDProxy]]] = None,
+        data: Optional[List[Union[Data, UIDProxy]]] = None,
+        computation: Optional[List[Union[Computation, UIDProxy]]] = None,
+        citation: Optional[List[Union[Citation, UIDProxy]]] = None,
         notes: str = "",
         **kwargs
     ):
@@ -372,7 +373,7 @@ def uncertainty_type(self) -> str:
 
     @property
     @beartype
-    def component(self) -> List[Material]:
+    def component(self) -> List[Union[Material, UIDProxy]]:
         """
         list of Materials that the Property relates to
 
@@ -392,7 +393,7 @@ def component(self) -> List[Material]:
 
     @component.setter
     @beartype
-    def component(self, new_component: List[Material]) -> None:
+    def component(self, new_component: List[Union[Material, UIDProxy]]) -> None:
         """
         set the list of Materials as components for the Property subobject
 
@@ -486,7 +487,7 @@ def method(self, new_method: str) -> None:
 
     @property
     @beartype
-    def sample_preparation(self) -> Union[Process, None]:
+    def sample_preparation(self) -> Union[Process, None, UIDProxy]:
         """
         sample_preparation
 
@@ -506,7 +507,7 @@ def sample_preparation(self) -> Union[Process, None]:
 
     @sample_preparation.setter
     @beartype
-    def sample_preparation(self, new_sample_preparation: Union[Process, None]) -> None:
+    def sample_preparation(self, new_sample_preparation: Union[Process, None, UIDProxy]) -> None:
         """
         set the sample_preparation for the Property subobject
 
@@ -524,7 +525,7 @@ def sample_preparation(self, new_sample_preparation: Union[Process, None]) -> No
 
     @property
     @beartype
-    def condition(self) -> List[Condition]:
+    def condition(self) -> List[Union[Condition, UIDProxy]]:
         """
         list of Conditions under which the property was measured
 
@@ -544,7 +545,7 @@ def condition(self) -> List[Condition]:
 
     @condition.setter
     @beartype
-    def condition(self, new_condition: List[Condition]) -> None:
+    def condition(self, new_condition: List[Union[Condition, UIDProxy]]) -> None:
         """
         set the list of Conditions for this property subobject
 
@@ -562,7 +563,7 @@ def condition(self, new_condition: List[Condition]) -> None:
 
     @property
     @beartype
-    def data(self) -> List[Data]:
+    def data(self) -> List[Union[Data, UIDProxy]]:
         """
         List of Data nodes for this Property subobjects
 
@@ -589,7 +590,7 @@ def data(self) -> List[Data]:
 
     @data.setter
     @beartype
-    def data(self, new_data: List[Data]) -> None:
+    def data(self, new_data: List[Union[Data, UIDProxy]]) -> None:
         """
         set the Data node for the Property subobject
 
@@ -607,7 +608,7 @@ def data(self, new_data: List[Data]) -> None:
 
     @property
     @beartype
-    def computation(self) -> List[Computation]:
+    def computation(self) -> List[Union[Computation, UIDProxy]]:
         """
         list of Computation nodes that produced this property
 
@@ -627,7 +628,7 @@ def computation(self) -> List[Computation]:
 
     @computation.setter
     @beartype
-    def computation(self, new_computation: List[Computation]) -> None:
+    def computation(self, new_computation: List[Union[Computation, UIDProxy]]) -> None:
         """
         set the list of Computation nodes that produced this property
 
@@ -645,7 +646,7 @@ def computation(self, new_computation: List[Computation]) -> None:
 
     @property
     @beartype
-    def citation(self) -> List[Citation]:
+    def citation(self) -> List[Union[Citation, UIDProxy]]:
         """
         list of Citation subobjects for this Property subobject
 
@@ -681,7 +682,7 @@ def citation(self) -> List[Citation]:
 
     @citation.setter
     @beartype
-    def citation(self, new_citation: List[Citation]) -> None:
+    def citation(self, new_citation: List[Union[Citation, UIDProxy]]) -> None:
         """
         set the list of Citation subobjects for the Property subobject
 
diff --git a/src/cript/nodes/subobjects/software_configuration.py b/src/cript/nodes/subobjects/software_configuration.py
index 02dbfa9bd..a7fc4f26e 100644
--- a/src/cript/nodes/subobjects/software_configuration.py
+++ b/src/cript/nodes/subobjects/software_configuration.py
@@ -6,6 +6,7 @@
 from cript.nodes.subobjects.algorithm import Algorithm
 from cript.nodes.subobjects.citation import Citation
 from cript.nodes.subobjects.software import Software
+from cript.nodes.util.json import UIDProxy
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
@@ -57,15 +58,15 @@ class SoftwareConfiguration(UUIDBaseNode):
 
     @dataclass(frozen=True)
     class JsonAttributes(UUIDBaseNode.JsonAttributes):
-        software: Union[Software, None] = None
-        algorithm: List[Algorithm] = field(default_factory=list)
+        software: Optional[Union[Software, UIDProxy]] = None
+        algorithm: List[Union[Algorithm, UIDProxy]] = field(default_factory=list)
         notes: str = ""
-        citation: List[Citation] = field(default_factory=list)
+        citation: List[Union[Citation, UIDProxy]] = field(default_factory=list)
 
     _json_attrs: JsonAttributes = JsonAttributes()
 
     @beartype
-    def __init__(self, software: Software, algorithm: Optional[List[Algorithm]] = None, notes: str = "", citation: Union[List[Citation], None] = None, **kwargs):
+    def __init__(self, software: Union[Software, UIDProxy], algorithm: Optional[List[Union[Algorithm, UIDProxy]]] = None, notes: str = "", citation: Union[List[Union[Citation, UIDProxy]], None] = None, **kwargs):
         """
         Create Software_Configuration sub-object
 
@@ -102,7 +103,7 @@ def __init__(self, software: Software, algorithm: Optional[List[Algorithm]] = No
 
     @property
     @beartype
-    def software(self) -> Union[Software, None]:
+    def software(self) -> Union[Software, None, UIDProxy]:
         """
         Software used
 
@@ -122,7 +123,7 @@ def software(self) -> Union[Software, None]:
 
     @software.setter
     @beartype
-    def software(self, new_software: Union[Software, None]) -> None:
+    def software(self, new_software: Union[Software, None, UIDProxy]) -> None:
         """
         set the Software used
 
@@ -140,7 +141,7 @@ def software(self, new_software: Union[Software, None]) -> None:
 
     @property
     @beartype
-    def algorithm(self) -> List[Algorithm]:
+    def algorithm(self) -> List[Union[Algorithm, UIDProxy]]:
         """
         list of Algorithms used
 
@@ -161,7 +162,7 @@ def algorithm(self) -> List[Algorithm]:
 
     @algorithm.setter
     @beartype
-    def algorithm(self, new_algorithm: List[Algorithm]) -> None:
+    def algorithm(self, new_algorithm: List[Union[Algorithm, UIDProxy]]) -> None:
         """
         set the list of Algorithms
 
@@ -224,7 +225,7 @@ def notes(self, new_notes: str) -> None:
 
     @property
     @beartype
-    def citation(self) -> List[Citation]:
+    def citation(self) -> List[Union[Citation, UIDProxy]]:
         """
         list of Citation sub-objects for the Software_Configuration
 
@@ -261,7 +262,7 @@ def citation(self) -> List[Citation]:
 
     @citation.setter
     @beartype
-    def citation(self, new_citation: List[Citation]) -> None:
+    def citation(self, new_citation: List[Union[Citation, UIDProxy]]) -> None:
         """
         set the Citation sub-object
 
diff --git a/src/cript/nodes/util/core.py b/src/cript/nodes/util/core.py
index 938ec7201..e1b5facc6 100644
--- a/src/cript/nodes/util/core.py
+++ b/src/cript/nodes/util/core.py
@@ -67,3 +67,16 @@ def get_orphaned_experiment_exception(orphaned_node):
         return CRIPTOrphanedComputationalProcessError(orphaned_node)
     # Base case raise the parent exception. TODO add bug warning.
     return CRIPTOrphanedExperimentError(orphaned_node)
+
+
+def iterate_leaves(obj):
+    """Helper function that iterates over all leaves of nested dictionaries or lists."""
+
+    if isinstance(obj, dict):
+        for value in obj.values():
+            yield from iterate_leaves(value)
+    elif isinstance(obj, list):
+        for item in obj:
+            yield from iterate_leaves(item)
+    else:
+        yield obj
diff --git a/src/cript/nodes/util/json.py b/src/cript/nodes/util/json.py
index 274c1df1c..2b923bab5 100644
--- a/src/cript/nodes/util/json.py
+++ b/src/cript/nodes/util/json.py
@@ -14,9 +14,21 @@
     CRIPTJsonDeserializationError,
     CRIPTJsonNodeError,
 )
+from cript.nodes.util.core import iterate_leaves
 from cript.nodes.uuid_base import UUIDBaseNode
 
 
+@dataclasses.dataclass(frozen=True)
+class UIDProxy:
+    """Helper class that store temporarily unresolved UIDs."""
+
+    uid: Optional[str] = None
+
+    def __post_init__(self):
+        if self.uid is None:
+            raise RuntimeError("UID needs to be initialized")
+
+
 class NodeEncoder(json.JSONEncoder):
     """
     Custom JSON encoder for serializing CRIPT nodes to JSON.
@@ -93,6 +105,10 @@ def default(self, obj):
         """
         if isinstance(obj, uuid.UUID):
             return str(obj)
+
+        if isinstance(obj, UIDProxy):
+            return obj.uid
+
         if isinstance(obj, BaseNode):
             try:
                 uid = obj.uid
@@ -136,21 +152,20 @@ def default(self, obj):
 
     def _apply_modifications(self, serialize_dict: Dict):
         """
-                Checks the serialize_dict to see if any other operations are required before it
-                can be considered done. If other operations are required, then it passes it to the other operations
-                and at the end returns the fully finished dict.
+        Checks the serialize_dict to see if any other operations are required before it
+        can be considered done. If other operations are required, then it passes it to the other operations
+        and at the end returns the fully finished dict.
 
-                This function is essentially a big switch case that checks the node type
-                and determines what other operations are required for it.
+        This function is essentially a big switch case that checks the node type
+        and determines what other operations are required for it.
 
-                Parameters
-                ----------
-        <<<<<<< HEAD
-                serialize_dict: Dict
+        Parameters
+        ----------
+        serialize_dict: Dict
 
-                Returns
-                -------
-                serialize_dict: Dict
+        Returns
+        -------
+        serialize_dict: Dict
         """
 
         def process_attribute(attribute):
@@ -221,7 +236,11 @@ def __init__(self, uid_cache: Optional[Dict] = None):
             uid_cache = {}
         self._uid_cache = uid_cache
 
-    def __call__(self, node_str: Union[Dict, str]) -> Dict:
+    @property
+    def uid_cache(self):
+        return self._uid_cache
+
+    def __call__(self, node_str: Union[Dict, str]) -> Union[Dict, UIDProxy]:
         """
         Internal function, used as a hook for json deserialization.
 
@@ -266,9 +285,9 @@ def __call__(self, node_str: Union[Dict, str]) -> Dict:
             try:
                 return self._uid_cache[node_dict["uid"]]
             except KeyError:
-                # TODO if we convince beartype to accept Proxy temporarily, enable return instead of raise
-                raise CRIPTDeserializationUIDError("Unknown", node_dict["uid"])
-                # return _UIDProxy(node_dict["uid"])
+                # raise CRIPTDeserializationUIDError("Unknown", node_dict["uid"])
+                proxy = UIDProxy(uid=node_dict["uid"])
+                return proxy
 
         try:
             node_type_list = node_dict["node"]
@@ -294,8 +313,35 @@ def __call__(self, node_str: Union[Dict, str]) -> Dict:
         # Fall back
         return node_dict
 
-
-def load_nodes_from_json(nodes_json: Union[str, Dict], _use_uuid_cache: Optional[Dict] = None):
+    def resolve_unresolved_uids(self, node_iter):
+        def handle_uid_replacement(node, name, attr):
+            if isinstance(attr, UIDProxy):
+                unresolved_uid = attr.uid
+                try:
+                    uid_node = self.uid_cache[unresolved_uid]
+                except KeyError as exc:
+                    raise CRIPTDeserializationUIDError("Unknown", unresolved_uid) from exc
+                updated_attrs = dataclasses.replace(node._json_attrs, **{name: uid_node})
+                node._update_json_attrs_if_valid(updated_attrs)
+
+        for node_leaves in iterate_leaves(node_iter):
+            if isinstance(node_leaves, BaseNode):
+                for node in node_leaves:
+                    field_names = [field.name for field in dataclasses.fields(node._json_attrs)]
+                    for field_name in field_names:
+                        field_attr = getattr(node._json_attrs, field_name)
+                        handle_uid_replacement(node, field_name, field_attr)
+                        if isinstance(field_attr, list):
+                            for i in range(len(field_attr)):
+                                if isinstance(field_attr[i], UIDProxy):
+                                    try:
+                                        field_attr[i] = self.uid_cache[field_attr[i].uid]
+                                    except KeyError as exc:
+                                        raise CRIPTDeserializationUIDError("Unknown", field_attr[i].uid) from exc
+        return node_iter
+
+
+def load_nodes_from_json(nodes_json: Union[str, Dict], api=None, _use_uuid_cache: Optional[Dict] = None, skip_validation: bool = False):
     """
     User facing function, that return a node and all its children from a json string input.
 
@@ -343,6 +389,11 @@ def load_nodes_from_json(nodes_json: Union[str, Dict], _use_uuid_cache: Optional
         Typically returns a single CRIPT node,
         but if given a list of nodes, then it will serialize them and return a list of CRIPT nodes
     """
+    from cript.api.api import _get_global_cached_api
+
+    if api is None:
+        api = _get_global_cached_api()
+
     # Initialize the custom decoder hook for JSON deserialization
     node_json_hook = _NodeDecoderHook()
 
@@ -357,11 +408,22 @@ def load_nodes_from_json(nodes_json: Union[str, Dict], _use_uuid_cache: Optional
     if _use_uuid_cache is not None:  # If requested use a custom cache.
         UUIDBaseNode._uuid_cache = _use_uuid_cache
 
+    previous_skip_validation = api.schema.skip_validation
+    # Temporarily disable validation while loading nodes from JSON
+    api.schema.skip_validation = True
     try:
         loaded_nodes = json.loads(nodes_json, object_hook=node_json_hook)
+        loaded_nodes = node_json_hook.resolve_unresolved_uids(loaded_nodes)
     finally:
         # Definitively restore the old cache state
         UUIDBaseNode._uuid_cache = previous_uuid_cache
+        api.schema.skip_validation = previous_skip_validation
+
+    # If nodes are actually expected to be checked, do it now
+    if not previous_skip_validation and not skip_validation:
+        for node in iterate_leaves(loaded_nodes):
+            if isinstance(node, BaseNode):
+                node.validate()
 
     if _use_uuid_cache is not None:
         return loaded_nodes, _use_uuid_cache
@@ -399,41 +461,3 @@ def _is_node_field_valid(node_type_list: List) -> bool:
         return True
     else:
         return False
-
-
-# class _UIDProxy:
-#     """
-#     Proxy class for unresolvable UID nodes.
-#     This is going to be replaced by actual nodes.
-
-#     Report a bug if you find this class in production.
-#     """
-
-#     def __init__(self, uid: str):
-#         self.uid = uid
-#         print("proxy", uid)
-
-# TODO: enable this logic to replace proxies, once beartype is OK with that.
-# def recursive_proxy_replacement(node, handled_nodes):
-#     if isinstance(node, _UIDProxy):
-#         try:
-#             node = node_json_hook._uid_cache[node.uid]
-#         except KeyError as exc:
-#             raise CRIPTDeserializationUIDError(node.node_type, node.uid)
-#         return node
-#     handled_nodes.add(node.uid)
-#     for field in node._json_attrs.__dict__:
-#         child_node = getattr(node._json_attrs, field)
-#         if not isinstance(child_node, List):
-#             if hasattr(cn, "__bases__") and BaseNode in child_node.__bases__:
-#                 child_node = recursive_proxy_replacement(child_node, handled_nodes)
-#                 node._json_attrs = replace(node._json_attrs, field=child_node)
-#         else:
-#             for i, cn in enumerate(child_node):
-#                 if hasattr(cn, "__bases__") and BaseNode in cn.__bases__:
-#                     if cn.uid not in handled_nodes:
-#                         child_node[i] = recursive_proxy_replacement(cn, handled_nodes)
-
-#     return node
-# handled_nodes = set()
-# recursive_proxy_replacement(json_nodes, handled_nodes)
diff --git a/src/cript/nodes/uuid_base.py b/src/cript/nodes/uuid_base.py
index 87fac9043..ca2e5c319 100644
--- a/src/cript/nodes/uuid_base.py
+++ b/src/cript/nodes/uuid_base.py
@@ -3,8 +3,11 @@
 from dataclasses import dataclass, field, replace
 from typing import Any, Dict, Optional
 
+from beartype import beartype
+
 from cript.nodes.core import BaseNode
 from cript.nodes.exceptions import CRIPTUUIDException
+from cript.nodes.node_iterator import NodeIterator
 
 
 class UUIDBaseNode(BaseNode, ABC):
@@ -30,7 +33,7 @@ class JsonAttributes(BaseNode.JsonAttributes):
     _json_attrs: JsonAttributes = JsonAttributes()
 
     def __new__(cls, *args, **kwargs):
-        uuid: Optional[str] = kwargs.get("uuid")
+        uuid: Optional[str] = str(kwargs.get("uuid"))
         if uuid and uuid in UUIDBaseNode._uuid_cache:
             existing_node_to_overwrite = UUIDBaseNode._uuid_cache[uuid]
             if type(existing_node_to_overwrite) is not cls:
@@ -51,8 +54,13 @@ def __init__(self, **kwargs):
         UUIDBaseNode._uuid_cache[uuid] = self
 
     @property
-    def uuid(self) -> uuid.UUID:
-        return uuid.UUID(self._json_attrs.uuid)
+    @beartype
+    def uuid(self) -> str:
+        if not isinstance(self._json_attrs.uuid, str):
+            # Some JSON decoding automatically converted this to UUID objects, which we don't want
+            self._json_attrs = replace(self._json_attrs, uuid=str(self._json_attrs.uuid))
+
+        return self._json_attrs.uuid
 
     @property
     def url(self):
@@ -76,3 +84,7 @@ def updated_at(self):
     @property
     def created_at(self):
         return self._json_attrs.created_at
+
+    def __iter__(self) -> NodeIterator:
+        """Enables DFS iteration over all children."""
+        return NodeIterator(self)
diff --git a/tests/fixtures/primary_nodes.py b/tests/fixtures/primary_nodes.py
index 65fbf0222..063a3a334 100644
--- a/tests/fixtures/primary_nodes.py
+++ b/tests/fixtures/primary_nodes.py
@@ -26,15 +26,15 @@ def complex_project_dict(complex_collection_node, simple_material_node, complex_
     project_dict = {"node": ["Project"]}
     project_dict["locked"] = True
     project_dict["model_version"] = "1.0.0"
-    project_dict["updated_by"] = json.loads(copy.deepcopy(complex_user_node).get_json(condense_to_uuid={}).json)
-    project_dict["created_by"] = json.loads(complex_user_node.get_json(condense_to_uuid={}).json)
+    project_dict["updated_by"] = json.loads(copy.deepcopy(complex_user_node).get_expanded_json())
+    project_dict["created_by"] = json.loads(complex_user_node.get_expanded_json())
     project_dict["public"] = True
     project_dict["name"] = "my project name"
     project_dict["notes"] = "my project notes"
-    project_dict["member"] = [json.loads(complex_user_node.get_json(condense_to_uuid={}).json)]
-    project_dict["admin"] = [json.loads(complex_user_node.get_json(condense_to_uuid={}).json)]
-    project_dict["collection"] = [json.loads(complex_collection_node.get_json(condense_to_uuid={}).json)]
-    project_dict["material"] = [json.loads(copy.deepcopy(simple_material_node).get_json(condense_to_uuid={}).json)]
+    project_dict["member"] = [json.loads(complex_user_node.get_expanded_json())]
+    project_dict["admin"] = [json.loads(complex_user_node.get_expanded_json())]
+    project_dict["collection"] = [json.loads(complex_collection_node.get_expanded_json())]
+    project_dict["material"] = [json.loads(copy.deepcopy(simple_material_node).get_expanded_json())]
     return project_dict
 
 
@@ -47,6 +47,387 @@ def complex_project_node(complex_project_dict) -> cript.Project:
     return complex_project
 
 
+@pytest.fixture(scope="function")
+def fixed_cyclic_project_node() -> cript.Project:
+    project_json_string: str = "{\n"
+    project_json_string += '"node": ["Project"],\n'
+    project_json_string += '"uid": "_:0e487131-1dbf-4c6c-9ee0-650df148b06e",\n'
+    project_json_string += '"uuid": "55a41f23-4791-4dc7-bf2c-48fd2b6fc90b",\n'
+    project_json_string += '"updated_by": {\n'
+    project_json_string += '"node": ["User"],\n'
+    project_json_string += '"uid": "_:5838e9cc-f01d-468e-96de-93bfe6fb758f",\n'
+    project_json_string += '"uuid": "5838e9cc-f01d-468e-96de-93bfe6fb758f",\n'
+    project_json_string += '"created_at": "2024-03-12 15:58:12.486673",\n'
+    project_json_string += '"updated_at": "2024-03-12 15:58:12.486681",\n'
+    project_json_string += '"email": "test@emai.com",\n'
+    project_json_string += '"model_version": "1.0.0",\n'
+    project_json_string += '"orcid": "0000-0002-0000-0000",\n'
+    project_json_string += '"picture": "/my/picture/path",\n'
+    project_json_string += '"username": "testuser"\n'
+    project_json_string += "},\n"
+    project_json_string += '"created_by": {\n'
+    project_json_string += '"node": ["User"],\n'
+    project_json_string += '"uid": "_:2bb1fc16-6e72-480d-a3df-b74eac4d32e8",\n'
+    project_json_string += '"uuid": "ab385d26-6ee5-40d4-9095-2d623616a162",\n'
+    project_json_string += '"created_at": "2024-03-12 15:58:12.486673",\n'
+    project_json_string += '"updated_at": "2024-03-12 15:58:12.486681",\n'
+    project_json_string += '"email": "test@emai.com",\n'
+    project_json_string += '"model_version": "1.0.0",\n'
+    project_json_string += '"orcid": "0000-0002-0000-0000",\n'
+    project_json_string += '"picture": "/my/picture/path",\n'
+    project_json_string += '"username": "testuser"\n'
+    project_json_string += "},\n"
+    project_json_string += '"locked": true,\n'
+    project_json_string += '"model_version": "1.0.0",\n'
+    project_json_string += '"public": true,\n'
+    project_json_string += '"name": "my project name",\n'
+    project_json_string += '"notes": "my project notes",\n'
+    project_json_string += '"member": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:2bb1fc16-6e72-480d-a3df-b74eac4d32e8"\n'
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"admin": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:2bb1fc16-6e72-480d-a3df-b74eac4d32e8"\n'
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"collection": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Collection"],\n'
+    project_json_string += '"uid": "_:61a99328-108b-4307-bfcb-fccd12a5dd91",\n'
+    project_json_string += '"uuid": "61a99328-108b-4307-bfcb-fccd12a5dd91",\n'
+    project_json_string += '"name": "my complex collection name",\n'
+    project_json_string += '"experiment": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Experiment"],\n'
+    project_json_string += '"uid": "_:d2b3169d-c200-4143-811a-a0d07439dd96",\n'
+    project_json_string += '"uuid": "d2b3169d-c200-4143-811a-a0d07439dd96",\n'
+    project_json_string += '"name": "my experiment name",\n'
+    project_json_string += '"process": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Process"],\n'
+    project_json_string += '"uid": "_:5d649b93-8f2c-4509-9aa7-311213df9405",\n'
+    project_json_string += '"uuid": "5d649b93-8f2c-4509-9aa7-311213df9405",\n'
+    project_json_string += '"name": "my process name",\n'
+    project_json_string += '"type": "affinity_pure",\n'
+    project_json_string += '"ingredient": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Ingredient"],\n'
+    project_json_string += '"uid": "_:21601ad5-c225-4626-8baa-3a7c1d64cafa",\n'
+    project_json_string += '"uuid": "21601ad5-c225-4626-8baa-3a7c1d64cafa",\n'
+    project_json_string += '"material": {\n'
+    project_json_string += '"node": ["Material"],\n'
+    project_json_string += '"uid": "_:ea9ad3e7-84a7-475f-82a8-16f5b9241e37",\n'
+    project_json_string += '"uuid": "ea9ad3e7-84a7-475f-82a8-16f5b9241e37",\n'
+    project_json_string += '"name": "my test material 9221be1d-247c-4f67-8a0a-fe1ec657705b",\n'
+    project_json_string += '"property": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Property"],\n'
+    project_json_string += '"uid": "_:fc504202-6fdd-43c7-830d-40c7d3f0cb8c",\n'
+    project_json_string += '"uuid": "fc504202-6fdd-43c7-830d-40c7d3f0cb8c",\n'
+    project_json_string += '"key": "modulus_shear",\n'
+    project_json_string += '"type": "value",\n'
+    project_json_string += '"value": 5.0,\n'
+    project_json_string += '"unit": "GPa",\n'
+    project_json_string += '"computation": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Computation"],\n'
+    project_json_string += '"uid": "_:175708fa-cc29-4442-be7f-adf85e995330",\n'
+    project_json_string += '"uuid": "175708fa-cc29-4442-be7f-adf85e995330",\n'
+    project_json_string += '"name": "my computation name",\n'
+    project_json_string += '"type": "analysis",\n'
+    project_json_string += '"input_data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Data"],\n'
+    project_json_string += '"uid": "_:dcb516a1-951d-461a-beb6-bdf2aecd0778",\n'
+    project_json_string += '"uuid": "dcb516a1-951d-461a-beb6-bdf2aecd0778",\n'
+    project_json_string += '"name": "my data name",\n'
+    project_json_string += '"type": "afm_amp",\n'
+    project_json_string += '"file": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["File"],\n'
+    project_json_string += '"uid": "_:c94aba31-adf2-4eeb-b51e-8c70568c2eb0",\n'
+    project_json_string += '"uuid": "c94aba31-adf2-4eeb-b51e-8c70568c2eb0",\n'
+    project_json_string += '"name": "my complex file node fixture",\n'
+    project_json_string += '"source": "https://criptapp.org",\n'
+    project_json_string += '"type": "calibration",\n'
+    project_json_string += '"extension": ".csv",\n'
+    project_json_string += '"data_dictionary": "my file\'s data dictionary"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"output_data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Data"],\n'
+    project_json_string += '"uid": "_:6a2e81af-861b-4c66-96fd-b969a38b81b1",\n'
+    project_json_string += '"uuid": "6a2e81af-861b-4c66-96fd-b969a38b81b1",\n'
+    project_json_string += '"name": "my data name",\n'
+    project_json_string += '"type": "afm_amp",\n'
+    project_json_string += '"file": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["File"],\n'
+    project_json_string += '"uid": "_:ce01ba93-cfc5-4265-a6d6-8c38397deb43",\n'
+    project_json_string += '"uuid": "ce01ba93-cfc5-4265-a6d6-8c38397deb43",\n'
+    project_json_string += '"name": "my complex file node fixture",\n'
+    project_json_string += '"source": "https://criptapp.org",\n'
+    project_json_string += '"type": "calibration",\n'
+    project_json_string += '"extension": ".csv",\n'
+    project_json_string += '"data_dictionary": "my file\'s data dictionary"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Computation"],\n'
+    project_json_string += '"uid": "_:1aa11462-b394-4c35-906e-d0e9198be6da",\n'
+    project_json_string += '"uuid": "1aa11462-b394-4c35-906e-d0e9198be6da",\n'
+    project_json_string += '"name": "my computation name",\n'
+    project_json_string += '"type": "analysis",\n'
+    project_json_string += '"input_data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:dcb516a1-951d-461a-beb6-bdf2aecd0778"\n'
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"output_data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:6a2e81af-861b-4c66-96fd-b969a38b81b1"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"parent_material": {\n'
+    project_json_string += '"node": ["Material"],\n'
+    project_json_string += '"uid": "_:2ee56671-5efb-4f99-a7ea-d659f5b5dd9a",\n'
+    project_json_string += '"uuid": "2ee56671-5efb-4f99-a7ea-d659f5b5dd9a",\n'
+    project_json_string += '"name": "my test material 9221be1d-247c-4f67-8a0a-fe1ec657705b",\n'
+    project_json_string += '"process": {\n'
+    project_json_string += '"uid": "_:5d649b93-8f2c-4509-9aa7-311213df9405"\n'
+    project_json_string += "},\n"
+    project_json_string += '"property": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Property"],\n'
+    project_json_string += '"uid": "_:fde629f5-8d3a-4546-8cd3-9de63b990187",\n'
+    project_json_string += '"uuid": "fde629f5-8d3a-4546-8cd3-9de63b990187",\n'
+    project_json_string += '"key": "modulus_shear",\n'
+    project_json_string += '"type": "value",\n'
+    project_json_string += '"value": 5.0,\n'
+    project_json_string += '"unit": "GPa",\n'
+    project_json_string += '"computation": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Computation"],\n'
+    project_json_string += '"uid": "_:2818ed85-2758-45f9-9f30-5c3dfedd3d33",\n'
+    project_json_string += '"uuid": "2818ed85-2758-45f9-9f30-5c3dfedd3d33",\n'
+    project_json_string += '"name": "my computation name",\n'
+    project_json_string += '"type": "analysis",\n'
+    project_json_string += '"input_data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Data"],\n'
+    project_json_string += '"uid": "_:0a88e09d-488f-45ed-ad9c-14873792b8fd",\n'
+    project_json_string += '"uuid": "0a88e09d-488f-45ed-ad9c-14873792b8fd",\n'
+    project_json_string += '"name": "my data name",\n'
+    project_json_string += '"type": "afm_amp",\n'
+    project_json_string += '"file": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["File"],\n'
+    project_json_string += '"uid": "_:1fc95012-2845-46ac-a8e3-7178fe19afcd",\n'
+    project_json_string += '"uuid": "1fc95012-2845-46ac-a8e3-7178fe19afcd",\n'
+    project_json_string += '"name": "my complex file node fixture",\n'
+    project_json_string += '"source": "https://criptapp.org",\n'
+    project_json_string += '"type": "calibration",\n'
+    project_json_string += '"extension": ".csv",\n'
+    project_json_string += '"data_dictionary": "my file\'s data dictionary"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"output_data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Data"],\n'
+    project_json_string += '"uid": "_:309b0d7b-027c-4422-ab5f-58069fe4adb1",\n'
+    project_json_string += '"uuid": "309b0d7b-027c-4422-ab5f-58069fe4adb1",\n'
+    project_json_string += '"name": "my data name",\n'
+    project_json_string += '"type": "afm_amp",\n'
+    project_json_string += '"file": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["File"],\n'
+    project_json_string += '"uid": "_:e78cf3cf-de6c-4364-93c4-4fb3d352bde2",\n'
+    project_json_string += '"uuid": "e78cf3cf-de6c-4364-93c4-4fb3d352bde2",\n'
+    project_json_string += '"name": "my complex file node fixture",\n'
+    project_json_string += '"source": "https://criptapp.org",\n'
+    project_json_string += '"type": "calibration",\n'
+    project_json_string += '"extension": ".csv",\n'
+    project_json_string += '"data_dictionary": "my file\'s data dictionary"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Computation"],\n'
+    project_json_string += '"uid": "_:09cf72a4-a397-4953-baa6-7cdf5be067c4",\n'
+    project_json_string += '"uuid": "09cf72a4-a397-4953-baa6-7cdf5be067c4",\n'
+    project_json_string += '"name": "my computation name",\n'
+    project_json_string += '"type": "analysis",\n'
+    project_json_string += '"input_data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:0a88e09d-488f-45ed-ad9c-14873792b8fd"\n'
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"output_data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:309b0d7b-027c-4422-ab5f-58069fe4adb1"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"bigsmiles": "{[][$]COC[$][]}"\n'
+    project_json_string += "},\n"
+    project_json_string += '"bigsmiles": "{[][$]COC[$][]}"\n'
+    project_json_string += "}\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"product": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:ea9ad3e7-84a7-475f-82a8-16f5b9241e37"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"computation": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:2818ed85-2758-45f9-9f30-5c3dfedd3d33"\n'
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:09cf72a4-a397-4953-baa6-7cdf5be067c4"\n'
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:175708fa-cc29-4442-be7f-adf85e995330"\n'
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:1aa11462-b394-4c35-906e-d0e9198be6da"\n'
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"data": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:0a88e09d-488f-45ed-ad9c-14873792b8fd"\n'
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:309b0d7b-027c-4422-ab5f-58069fe4adb1"\n'
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:dcb516a1-951d-461a-beb6-bdf2aecd0778"\n'
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:6a2e81af-861b-4c66-96fd-b969a38b81b1"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"inventory": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Inventory"],\n'
+    project_json_string += '"uid": "_:1ff50987-e0a2-4aa3-a1a2-bdcefd54693d",\n'
+    project_json_string += '"uuid": "1ff50987-e0a2-4aa3-a1a2-bdcefd54693d",\n'
+    project_json_string += '"name": "my inventory name",\n'
+    project_json_string += '"material": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:ea9ad3e7-84a7-475f-82a8-16f5b9241e37"\n'
+    project_json_string += "},\n"
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Material"],\n'
+    project_json_string += '"uid": "_:845c90c1-5a93-416f-9c42-1bac1de0bd9a",\n'
+    project_json_string += '"uuid": "845c90c1-5a93-416f-9c42-1bac1de0bd9a",\n'
+    project_json_string += '"name": "material 2 730f2483-f018-4583-82d3-beb27947d470",\n'
+    project_json_string += '"process": {\n'
+    project_json_string += '"uid": "_:5d649b93-8f2c-4509-9aa7-311213df9405"\n'
+    project_json_string += "},\n"
+    project_json_string += '"property": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:fc504202-6fdd-43c7-830d-40c7d3f0cb8c"\n'
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"bigsmiles": "{[][$]COC[$][]}"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"doi": "10.1038/1781168a0",\n'
+    project_json_string += '"citation": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"node": ["Citation"],\n'
+    project_json_string += '"uid": "_:1232d7be-d870-4357-bf41-f53a09707cca",\n'
+    project_json_string += '"uuid": "1232d7be-d870-4357-bf41-f53a09707cca",\n'
+    project_json_string += '"type": "reference",\n'
+    project_json_string += '"reference": {\n'
+    project_json_string += '"node": ["Reference"],\n'
+    project_json_string += '"uid": "_:3fb7801f-7253-4d6b-813b-f1d2d25b6316",\n'
+    project_json_string += '"uuid": "3fb7801f-7253-4d6b-813b-f1d2d25b6316",\n'
+    project_json_string += '"type": "journal_article",\n'
+    project_json_string += '"title": "Multi-architecture Monte-Carlo (MC) simulation of soft coarse-grained polymeric materials: SOft coarse grained Monte-Carlo Acceleration (SOMA)",\n'
+    project_json_string += '"author": ["Ludwig Schneider", "Marcus M\u00fcller"],\n'
+    project_json_string += '"journal": "Computer Physics Communications",\n'
+    project_json_string += '"publisher": "Elsevier",\n'
+    project_json_string += '"year": 2019,\n'
+    project_json_string += '"pages": [463, 476],\n'
+    project_json_string += '"doi": "10.1016/j.cpc.2018.08.011",\n'
+    project_json_string += '"issn": "0010-4655",\n'
+    project_json_string += '"website": "https://www.sciencedirect.com/science/article/pii/S0010465518303072"\n'
+    project_json_string += "}\n"
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+    project_json_string += "],\n"
+    project_json_string += '"material": [\n'
+    project_json_string += "{\n"
+    project_json_string += '"uid": "_:2ee56671-5efb-4f99-a7ea-d659f5b5dd9a"\n'
+    project_json_string += "}\n"
+    project_json_string += "]\n"
+    project_json_string += "}\n"
+
+    return cript.load_nodes_from_json(project_json_string)
+
+
+@pytest.fixture(scope="function")
+def fixed_cyclic_project_dfs_uuid_order():
+    expected_list = [
+        "55a41f23-4791-4dc7-bf2c-48fd2b6fc90b",
+        "ab385d26-6ee5-40d4-9095-2d623616a162",
+        "61a99328-108b-4307-bfcb-fccd12a5dd91",
+        "1232d7be-d870-4357-bf41-f53a09707cca",
+        "3fb7801f-7253-4d6b-813b-f1d2d25b6316",
+        "d2b3169d-c200-4143-811a-a0d07439dd96",
+        "2818ed85-2758-45f9-9f30-5c3dfedd3d33",
+        "0a88e09d-488f-45ed-ad9c-14873792b8fd",
+        "1fc95012-2845-46ac-a8e3-7178fe19afcd",
+        "309b0d7b-027c-4422-ab5f-58069fe4adb1",
+        "e78cf3cf-de6c-4364-93c4-4fb3d352bde2",
+        "09cf72a4-a397-4953-baa6-7cdf5be067c4",
+        "175708fa-cc29-4442-be7f-adf85e995330",
+        "dcb516a1-951d-461a-beb6-bdf2aecd0778",
+        "c94aba31-adf2-4eeb-b51e-8c70568c2eb0",
+        "6a2e81af-861b-4c66-96fd-b969a38b81b1",
+        "ce01ba93-cfc5-4265-a6d6-8c38397deb43",
+        "1aa11462-b394-4c35-906e-d0e9198be6da",
+        "5d649b93-8f2c-4509-9aa7-311213df9405",
+        "21601ad5-c225-4626-8baa-3a7c1d64cafa",
+        "ea9ad3e7-84a7-475f-82a8-16f5b9241e37",
+        "2ee56671-5efb-4f99-a7ea-d659f5b5dd9a",
+        "fde629f5-8d3a-4546-8cd3-9de63b990187",
+        "fc504202-6fdd-43c7-830d-40c7d3f0cb8c",
+        "1ff50987-e0a2-4aa3-a1a2-bdcefd54693d",
+        "845c90c1-5a93-416f-9c42-1bac1de0bd9a",
+        "5838e9cc-f01d-468e-96de-93bfe6fb758f",
+    ]
+    return expected_list
+
+
 @pytest.fixture(scope="function")
 def simple_collection_node(simple_experiment_node) -> cript.Collection:
     """
@@ -244,10 +625,10 @@ def complex_material_dict(simple_property_node, simple_process_node, complex_com
 
     material_dict = {"node": ["Material"]}
     material_dict["name"] = "my complex material"
-    material_dict["property"] = [json.loads(simple_property_node.get_json(condense_to_uuid={}).json)]
-    material_dict["process"] = json.loads(simple_process_node.get_json(condense_to_uuid={}).json)
-    material_dict["parent_material"] = json.loads(simple_material_node.get_json(condense_to_uuid={}).json)
-    material_dict["computational_forcefield"] = json.loads(complex_computational_forcefield_node.get_json(condense_to_uuid={}).json)
+    material_dict["property"] = [json.loads(simple_property_node.get_expanded_json())]
+    material_dict["process"] = json.loads(simple_process_node.get_expanded_json())
+    material_dict["parent_material"] = json.loads(simple_material_node.get_expanded_json())
+    material_dict["computational_forcefield"] = json.loads(complex_computational_forcefield_node.get_expanded_json())
     material_dict["bigsmiles"] = "{[][$]CC[$][]}"
     material_dict["keyword"] = my_material_keyword
 
diff --git a/tests/test_node_util.py b/tests/test_node_util.py
index 806d4799b..a1125ceda 100644
--- a/tests/test_node_util.py
+++ b/tests/test_node_util.py
@@ -187,28 +187,22 @@ def test_local_search(simple_algorithm_node, complex_parameter_node):
     find_algorithms = a.find_children({"parameter": [{"key": "damping_time"}, {"key": "update_frequency"}, {"foo": "bar"}]})
     assert find_algorithms == []
 
+    # Test search depth exclusions
+    find_algorithms = a.find_children({"node": "Algorithm", "key": "mc_barostat"}, search_depth=0)
+    assert find_algorithms == [a]
+    find_parameter = a.find_children({"node": ["Parameter"]}, search_depth=1)
+    assert find_parameter == [p1, p2]
+    find_parameter = a.find_children({"node": ["Parameter"]}, search_depth=0)
+    assert find_parameter == []
+
+
+def test_cycles(fixed_cyclic_project_node):
+    new_project = fixed_cyclic_project_node
+    new_json = new_project.get_expanded_json()
 
-def test_cycles(complex_data_node, simple_computation_node):
-    # We create a wrong cycle with parameters here.
-    # TODO replace this with nodes that actually can form a cycle
-    d = copy.deepcopy(complex_data_node)
-    c = copy.deepcopy(simple_computation_node)
-    d.computation += [c]
-    # Using input and output data guarantees a cycle here.
-    c.output_data += [d]
-    c.input_data += [d]
-
-    # # Test the repetition of a citation.
-    # # Notice that we do not use a deepcopy here, as we want the citation to be the exact same node.
-    # citation = d.citation[0]
-    # # c._json_attrs.citation.append(citation)
-    # c.citation += [citation]
-    # # print(c.get_json(indent=2).json)
-    # # c.validate()
-
-    # Generate json with an implicit cycle
-    c.json
-    d.json
+    reloaded_project, cache = cript.load_nodes_from_json(new_json, _use_uuid_cache=dict())
+    assert reloaded_project is not new_project
+    assert reloaded_project.uuid == new_project.uuid
 
 
 def test_uid_serial(simple_inventory_node):
@@ -291,6 +285,7 @@ def test_invalid_project_graphs(simple_project_node, simple_material_node, simpl
     # Now add an orphan data
     data = copy.deepcopy(simple_data_node)
     property.data = [data]
+
     with pytest.raises(CRIPTOrphanedDataError):
         project.validate()
     # Fix with the helper function
@@ -364,3 +359,8 @@ def test_uuid_cache_override(complex_project_node):
         new_node = cache[key]
         assert old_node.uuid == new_node.uuid
         assert old_node is not new_node
+
+
+def test_dfs_order(fixed_cyclic_project_node, fixed_cyclic_project_dfs_uuid_order):
+    for i, node in enumerate(fixed_cyclic_project_node):
+        assert node.uuid == fixed_cyclic_project_dfs_uuid_order[i]