diff --git a/mira/dkg/api.py b/mira/dkg/api.py
index 596e00540..c109beb1f 100644
--- a/mira/dkg/api.py
+++ b/mira/dkg/api.py
@@ -1,7 +1,8 @@
 """API endpoints."""
 
 import itertools as itt
-from typing import Any, List, Mapping, Optional, Union
+import os
+from typing import Any, List, Mapping, Optional, Union, Dict
 
 import pydantic
 from fastapi import APIRouter, Body, HTTPException, Path, Query, Request
@@ -10,7 +11,7 @@
 from scipy.spatial import distance
 from typing_extensions import Literal
 
-from mira.dkg.client import AskemEntity, Entity
+from mira.dkg.client import AskemEntity, Entity, Relation
 from mira.dkg.utils import DKG_REFINER_RELS
 
 __all__ = [
@@ -329,6 +330,36 @@ def get_relations(
         return [RelationResponse(subject=s, predicate=p, object=o) for s, p, o in records]
 
 
+active_add_relation_endpoint = os.getenv('MIRA_ADD_RELATION_ENDPOINT')
+
+if active_add_relation_endpoint:
+    @api_blueprint.post(
+        "/add_nodes",
+        response_model=None,
+        tags=["relations"],
+    )
+    def add_nodes(
+        request: Request,
+        node_list: List[Union[AskemEntity, Entity]]
+    ):
+        """Add a list of nodes to the DKG"""
+        for entity in node_list:
+            request.app.state.client.add_node(entity)
+
+    @api_blueprint.post(
+        "/add_relations",
+        response_model=None,
+        tags=["relations"],
+    )
+    def add_relations(
+        request: Request,
+        relation_list: List[Relation]
+    ):
+        """Add a list of relations to the DKG"""
+        for relation in relation_list:
+            request.app.state.client.add_relation(relation)
+
+
 class IsOntChildResult(BaseModel):
     """Result of a query to /is_ontological_child"""
 
diff --git a/mira/dkg/client.py b/mira/dkg/client.py
index d8101f1f5..7b9e2d162 100644
--- a/mira/dkg/client.py
+++ b/mira/dkg/client.py
@@ -41,6 +41,34 @@
 TxResult: TypeAlias = Optional[List[List[Any]]]
 
 
+class Relation(BaseModel):
+    """A relationship between two entities in the DKG"""
+    source_curie: str = Field(
+        description="The curie of the source node", example="probonto:k0000000"
+    )
+    target_curie: str = Field(
+        description="The curie of the target node", example="probonto:k0000007"
+    )
+    type: str = Field(
+        description="The type of the relation", example="has_parameter"
+    )
+    pred: str = Field(
+        description="The curie of the relation type",
+        example="probonto:c0000062"
+    )
+    source: str = Field(
+        description="The prefix of the relation curie", example="probonto"
+    )
+    graph: str = Field(
+        description="The URI of the relation",
+        example="https://raw.githubusercontent.com/probonto"
+                "/ontology/master/probonto4ols.owl"
+    )
+    version: str = Field(
+        description="The version number", example="2.5"
+    )
+
+
 class Entity(BaseModel):
     """An entity in the domain knowledge graph."""
 
@@ -307,6 +335,67 @@ def create_tx(self, query: str, **query_params):
                                              query,
                                              **query_params)
 
+    def add_node(self, entity):
+        """Add a node to the DKG
+
+        Parameters
+        ----------
+        entity:
+            The node object that will be added to the DKG
+        """
+        curie = entity.id
+        name = entity.name
+        type = entity.type
+        obsolete = entity.obsolete
+        description = entity.description
+        synonyms = entity.synonyms
+        alts = entity.alts
+        xrefs = entity.xrefs
+        labels = entity.labels
+
+        create_source_node_query = (
+            f"MERGE (n {{curie: '{curie}', "
+            f"name: '{name}', "
+            f"type: '{type}', "
+            f"obsolete: {obsolete}, "
+            f"description: '{description}', "
+            f"synonyms: {synonyms}, "
+            f"alts: {alts}, "
+            f"xrefs: {xrefs}, "
+            f"labels: {labels} }} )"
+        )
+
+        self.create_tx(create_source_node_query)
+
+    def add_relation(self, relation):
+        """Add a relation to the DKG
+
+        Parameters
+        ----------
+        relation:
+            The relation object that will be added to the DKG
+        """
+        source_curie = relation.source_curie
+        target_curie = relation.target_curie
+        type = relation.type
+        pred = relation.pred
+        source = relation.source
+        version = relation.version
+        graph = relation.graph
+
+        create_relation_query = (
+            f"MATCH (source_node {{curie: '{source_curie}'}}), "
+            f"(target_node {{curie: '{target_curie}'}}) "
+            f"MERGE (source_node)-[rel:{type}]->(target_node)"
+            f"SET rel.pred = '{pred}'"
+            f"SET rel.source = '{source}'"
+            f"SET rel.version = '{version}'"
+            f"SET rel.graph = '{graph}'"
+        )
+        
+        self.create_tx(create_relation_query)
+
+
     def create_single_property_node_index(
         self,
         index_name: str,