diff --git a/core/lib/Drupal/Core/Http/LinkRelationshipInterface.php b/core/lib/Drupal/Core/Http/LinkRelationshipInterface.php
new file mode 100644
index 0000000..11baf99
--- /dev/null
+++ b/core/lib/Drupal/Core/Http/LinkRelationshipInterface.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace Drupal\Core\Http;
+
+/**
+ * Defines a single relationship.
+ */
+interface LinkRelationshipInterface {
+
+  /**
+   * Returns the name/identifier of the link relationship.
+   *
+   * @return string
+   */
+  public function getName();
+
+  /**
+   * Returns the description of the link relationship.
+   *
+   * @return string
+   */
+  public function getDescription();
+
+  /**
+   * Returns the URL pointing to the reference of the link relationship.
+   *
+   * @return string
+   */
+  public function getReference();
+
+  /**
+   * Returns some extra notes about this link relationship.
+   *
+   * @return string
+   */
+  public function getNotes();
+
+}
diff --git a/core/tests/Drupal/KernelTests/Core/Http/LinkRelationshipsTest.php b/core/tests/Drupal/KernelTests/Core/Http/LinkRelationshipsTest.php
new file mode 100644
index 0000000..3073032
--- /dev/null
+++ b/core/tests/Drupal/KernelTests/Core/Http/LinkRelationshipsTest.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace Drupal\KErnelTests\Core\Http;
+
+use Drupal\Core\Http\LinkRelationship;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests link relationships in Drupal.
+ *
+ * @group HTTP
+ */
+class LinkRelationshipsTest extends KernelTestBase {
+
+  public function testAvailableLinkRelationships() {
+    /** @var \Drupal\Core\Http\LinkRelationshipManager $link_relationship_manager */
+    $link_relationship_manager = \Drupal::service('plugin.manager.link_relationship');
+    /** @var  $canonical */
+    /** @var \Drupal\Core\Http\LinkRelationshipInterface $canonical */
+    $canonical = $link_relationship_manager->createInstance('canonical');
+    $this->assertInstanceOf(LinkRelationship::class, $canonical);
+    $this->assertEquals('[RFC6596]', $canonical->getReference());
+
+    // Test a couple of examples
+    print_r(array_keys($link_relationship_manager->getDefinitions()));
+    $this->assertArraySubset(['about', 'original', 'type'], array_keys($link_relationship_manager->getDefinitions()));
+  }
+
+}