--- /dev/null
+<?php
+
+namespace Drupal\media_entity_instagram\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * Check if a value is a valid Instagram embed code/URL.
+ *
+ * @constraint(
+ * id = "InstagramEmbedCode",
+ * label = @Translation("Instagram embed code", context = "Validation"),
+ * type = { "link", "string", "string_long" }
+ * )
+ */
+class InstagramEmbedCodeConstraint extends Constraint {
+
+ /**
+ * The default violation message.
+ *
+ * @var string
+ */
+ public $message = 'Not valid Instagram URL/Embed code.';
+
+}