notifyResourceUpdated method

void notifyResourceUpdated(String uri, { Object? content, })

Send notifications/resources/updated for uri to the sessions subscribed to it (on 2026-07-28, to the subscriptions/listen streams that watch it).

content, when given, is added as a content key — not part of the specification, read by clients that want the new contents without a resources/read (mcp_client onResourceContentUpdated). It is one resource-contents entry: a ResourceContents, an EmbeddedResource (its resource is sent) or the JSON of either.

Implementation

void notifyResourceUpdated(String uri, {Object? content}) {
  final Map<String, dynamic>? contentJson = switch (content) {
    null => null,
    EmbeddedResource() => Map<String, dynamic>.from(
      content.resource.toJson(),
    ),
    ResourceContents() => Map<String, dynamic>.from(content.toJson()),
    Map() => Map<String, dynamic>.from(content),
    _ =>
      throw ArgumentError.value(
        content,
        'content',
        'is not resource contents',
      ),
  };
  // Invalidate cache
  _resourceCache.remove(uri);

  if (!isConnected || !capabilities.hasResources) return;

  // Build notification based on whether content is provided
  final Map<String, dynamic> notification;
  if (contentJson != null) {
    // Extended format: one resource-contents entry
    notification = {'uri': uri, 'content': contentJson};
  } else {
    // Standard MCP 2025-03-26 format (URI only)
    notification = {'uri': uri};
  }

  // 2026-07-28 (SEP-2577): fan out to `subscriptions/listen` streams whose
  // filter opted into this URI (independent of the legacy subscribe registry).
  _fanOutToSubscriptions(
    'notifications/resources/updated',
    notification,
    uri: uri,
  );

  final subscribers = _resourceSubscriptions[uri];
  if (subscribers == null || subscribers.isEmpty) return;

  for (final sessionId in subscribers) {
    if (_sessions.containsKey(sessionId)) {
      _sendNotification(
        sessionId,
        'notifications/resources/updated',
        notification,
      );
    }
  }
}