diff --git a/app/api/migrations/0009_annotations_relations_20210421_1445.py b/app/api/migrations/0009_annotations_relations_20210421_1445.py
new file mode 100644
index 00000000..7106b755
--- /dev/null
+++ b/app/api/migrations/0009_annotations_relations_20210421_1445.py
@@ -0,0 +1,34 @@
+# Generated by Django 3.1.6 on 2021-03-02 10:13
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0008_auto_20210302_1013'),
+    ]
+
+    operations = [
+        migrations.CreateModel(  # id_autogen, annotation_id_1, annotation_id_2, type, author, timestamp
+            name='RelationTypes',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.TextField(max_length=50)),
+                ('color', models.TextField(max_length=20)),
+                ('project', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='relation_types', to='api.Project'))
+            ],
+        ),
+        migrations.CreateModel(  # id_autogen, annotation_id_1, annotation_id_2, type, author, timestamp
+            name='AnnotationRelations',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('annotation_id_1', models.IntegerField()),
+                ('annotation_id_2', models.IntegerField()),
+                ('type', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='api.RelationTypes')),
+                ('timestamp', models.DateTimeField(auto_now_add=True))
+            ],
+        )
+    ]
diff --git a/app/api/models.py b/app/api/models.py
index cb367151..9fdaa41c 100644
--- a/app/api/models.py
+++ b/app/api/models.py
@@ -265,6 +265,25 @@ class SequenceAnnotation(Annotation):
         unique_together = ('document', 'user', 'label', 'start_offset', 'end_offset')
 
 
+class AnnotationRelations:
+    user = models.ForeignKey(User, on_delete=models.CASCADE)
+    timestamp = models.DateTimeField(auto_now_add=True)
+    annotation_id_1 = models.IntegerField()
+    annotation_id_2 = models.IntegerField()
+    type = models.CharField(max_length=50)
+
+    class Meta:
+        unique_together = ('timestamp', 'user', 'annotation_id_1', 'annotation_id_2', 'type')
+
+
+class RelationTypes:
+    color = models.TextField()
+    name = models.TextField()
+
+    class Meta:
+        unique_together = ('color', 'name')
+
+
 class Seq2seqAnnotation(Annotation):
     # Override AnnotationManager for custom functionality
     objects = Seq2seqAnnotationManager()