diff --git a/v2/swagger.yaml b/v2/swagger.yaml
index db39345..f520e8e 100644
--- a/v2/swagger.yaml
+++ b/v2/swagger.yaml
@@ -1744,6 +1744,54 @@ paths:
         500:
           description: Server Error
 
+  /user-postcard/seen:
+    post:
+      tags:
+        - postcard
+      summary: Mark received postcard as opened
+      operationId: userPostcardSeen
+      parameters:
+        - name: id
+          in: query
+          description: UserPostcard item ID
+          schema:
+            type: string
+            format: uuid
+          required: true
+      responses:
+        200:
+          description: Postcard marked as opened
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  success:
+                    type: boolean
+                    example: true
+                  data:
+                    type: object
+                    nullable: true
+                    example: null
+                  errors:
+                    type: object
+                    nullable: true
+                    example: null
+                  message:
+                    type: object
+                    nullable: true
+                    example: null
+        400:
+          description: Invalid input (malformed id)
+        401:
+          description: Unauthorized request
+        403:
+          description: Unauthorized request
+        404:
+          description: Postcard not found
+        500:
+          description: Server Error
+
   /article/news:
     get:
       tags:
@@ -9175,7 +9223,10 @@ components:
           type: string
         is_seen:
           type: boolean
-          description: Did user seen this postcard?
+          description: Whether the recipient has opened this postcard.
+        needShowEnvelope:
+          type: boolean
+          description: Whether the mobile app should show the unopened postcard envelope.
 
     userGroup:
       type: object
@@ -13898,4 +13949,4 @@ components:
 security:
   - SessionAuth: [ ]
   - ApiKeyAuth: [ ]
-  - BearerAuth: [ ]
\ No newline at end of file
+  - BearerAuth: [ ]