Struct NotificationMetaObject 

pub struct NotificationMetaObject {
    pub io_modelcontextprotocol_subscription_id: Option<RequestId>,
    pub extra: Option<Map<String, Value>>,
}

Latest MCP Protocol 2026_07_28 Extends {@link MetaObject} with additional notification-specific fields. All key naming rules from MetaObject apply.

JSON schema

{
 "description": "Extends {@link MetaObject} with additional notification-specific fields. All key naming rules from MetaObject apply.",
 "type": "object",
 "properties": {
   "io.modelcontextprotocol/subscriptionId": {
     "description": "Identifies the subscription stream a notification was delivered on. The\nserver MUST include this key on every notification delivered via a\n{@link SubscriptionsListenRequestsubscriptions/listen} stream, so the\nclient can correlate the notification with the originating subscription.\nThe key is absent on notifications not delivered via a subscription\nstream (e.g. progress notifications for an in-flight request), which is\nwhy it is optional here.\n\nThe value is the JSON-RPC ID of the subscriptions/listen request that\nopened the stream.",
     "$ref": "#/$defs/RequestId"
   }
 },
 "additionalProperties": {}
}

Fields

io_modelcontextprotocol_subscription_id: Option<RequestId>

Identifies the subscription stream a notification was delivered on. The server MUST include this key on every notification delivered via a {@link SubscriptionsListenRequestsubscriptions/listen} stream, so the client can correlate the notification with the originating subscription. The key is absent on notifications not delivered via a subscription stream (e.g. progress notifications for an in-flight request), which is why it is optional here. The value is the JSON-RPC ID of the subscriptions/listen request that opened the stream.

extra: Option<Map<String, Value>>

Trait Implementations

impl Clone for NotificationMetaObject

fn clone(&self) -> NotificationMetaObject

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NotificationMetaObject

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for NotificationMetaObject

fn default() -> NotificationMetaObject

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for NotificationMetaObject

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for NotificationMetaObject

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.