Trait NotificationDefinition

Source

pub trait NotificationDefinition:
    HasNotificationMetadata
    + HasNotificationPayload
    + HasNotificationRules {
    // Provided methods
    fn to_notification(&self) -> Notification { ... }
    fn validate(&self) -> Result<(), String> { ... }
}

Expand description

Complete MCP Notification Creation - Build real-time event broadcasting systems.

This trait represents a complete, working MCP notification that can broadcast real-time events to connected clients with structured payloads and routing rules. When you implement the required metadata traits, you automatically get NotificationDefinition for free via blanket implementation.

§What You’re Building

A notification is a real-time event system that:

Broadcasts events to connected clients instantly
Carries structured JSON payloads with event data
Supports routing rules for targeted delivery
Provides reliable event ordering and delivery

§How to Create a Notification

Implement these three traits on your struct:


// This struct will automatically implement NotificationDefinition!
struct FileChangeNotification {
    file_path: String,
    change_type: String,
    payload_data: Value,
}

impl FileChangeNotification {
    fn new(file_path: String, change_type: String) -> Self {
        let payload_data = json!({
            "path": file_path,
            "type": change_type,
            "timestamp": "2024-01-01T00:00:00Z"
        });
        Self { file_path, change_type, payload_data }
    }
}

impl HasNotificationMetadata for FileChangeNotification {
    fn method(&self) -> &str {
        "file/changed"
    }
}

impl HasNotificationPayload for FileChangeNotification {
    fn payload(&self) -> Option<&Value> {
        Some(&self.payload_data)
    }
}

impl HasNotificationRules for FileChangeNotification {
    fn priority(&self) -> u32 {
        1
    }
}

// Now you can use it with the server:
let notification = FileChangeNotification::new(
    "/workspace/src/main.rs".to_string(),
    "modified".to_string(),
);

// The notification automatically implements NotificationDefinition
let base_notification = notification.to_notification();