diff --git a/proto-docs/session.md b/proto-docs/session.md
index 0d9f468..a480f45 100644
--- a/proto-docs/session.md
+++ b/proto-docs/session.md
@@ -317,7 +317,7 @@ Session Token body.
 | Field | Type | Label | Description |
 | ----- | ---- | ----- | ----------- |
 | version | [uint32](#uint32) |  | Token version. |
-| nonce | [uint32](#uint32) |  | Random nonce to prevent collisions. |
+| appdata | [bytes](#bytes) |  | Application-specific data that can be used to store additional context. This field is optional and can contain any application-defined data. Maximum size: 1024 bytes. |
 | issuer | [neo.fs.v2.refs.OwnerID](#neo.fs.v2.refs.OwnerID) |  | Account that issued this token (who signed it). |
 | subjects | [Target](#neo.fs.v2.session.Target) | repeated | Accounts authorized by this token (who can use it). Maximum number of subjects: 8. |
 | lifetime | [TokenLifetime](#neo.fs.v2.session.TokenLifetime) |  | Lifetime of this token. |
diff --git a/session/types.proto b/session/types.proto
index 2bac3b2..9c4a2dc 100644
--- a/session/types.proto
+++ b/session/types.proto
@@ -345,8 +345,10 @@ message SessionTokenV2 {
     // Token version.
     uint32 version = 1 [json_name = "version"];
 
-    // Random nonce to prevent collisions.
-    uint32 nonce = 2 [json_name = "nonce"];
+    // Application-specific data that can be used to store additional context.
+    // This field is optional and can contain any application-defined data.
+    // Maximum size: 1024 bytes.
+    bytes appdata = 2 [json_name = "appdata"];
 
     // Account that issued this token (who signed it).
     neo.fs.v2.refs.OwnerID issuer = 3 [json_name = "issuer"];