diff --git a/packages/types/src/attachment.ts b/packages/types/src/attachment.ts
index 55cc795732ea..44f4123c7ad2 100644
--- a/packages/types/src/attachment.ts
+++ b/packages/types/src/attachment.ts
@@ -1,6 +1,27 @@
+/**
+ * An attachment to an event. This is used to upload arbitrary data to Sentry.
+ *
+ * Please take care to not add sensitive information in attachments.
+ *
+ * https://develop.sentry.dev/sdk/envelopes/#attachment
+ */
 export interface Attachment {
+  /**
+   * The attachment data. Can be a string or a binary data (byte array)
+   */
   data: string | Uint8Array;
+  /**
+   * The name of the uploaded file without a path component
+   */
   filename: string;
+  /**
+   * The content type of the attachment payload. Defaults to `application/octet-stream` if not specified.
+   *
+   * Any valid [media type](https://www.iana.org/assignments/media-types/media-types.xhtml) is allowed.
+   */
   contentType?: string;
-  attachmentType?: string;
+  /**
+   * The type of the attachment. Defaults to `event.attachment` if not specified.
+   */
+  attachmentType?: 'event.attachment' | 'event.minidump' | 'event.applecrashreport' | 'unreal.context' | 'unreal.logs';
 }