This is a relatively straightforward question. Can an workflow with an MCP trigger selectively send data back to the client before the workflow has completed in order to update the user on progress?
The MCP protocol implements a send() method and I haven’t found any implementation to use it within n8n.
Any help is appreciated.
MCP Send References
this._streamMapping.forEach((response) => {
response.end();
});
this._streamMapping.clear();
// Clear any pending responses
this._requestResponseMap.clear();
this.onclose?.();
}
async send(message: JSONRPCMessage, options?: { relatedRequestId?: RequestId }): Promise<void> {
let requestId = options?.relatedRequestId;
if (isJSONRPCResponse(message) || isJSONRPCError(message)) {
// If the message is a response, use the request ID from the message
requestId = message.id;
}
// Check if this message should be sent on the standalone SSE stream (no request ID)
// Ignore notifications from tools (which have relatedRequestId set)
// Those will be sent via dedicated response SSE streams
if (requestId === undefined) {
this._streamMapping.forEach((response) => {
response.end();
});
this._streamMapping.clear();
// Clear any pending responses
this._requestResponseMap.clear();
this.onclose?.();
}
async send(message: JSONRPCMessage, options?: { relatedRequestId?: RequestId }): Promise<void> {
let requestId = options?.relatedRequestId;
if (isJSONRPCResponse(message) || isJSONRPCError(message)) {
// If the message is a response, use the request ID from the message
requestId = message.id;
}
// Check if this message should be sent on the standalone SSE stream (no request ID)
// Ignore notifications from tools (which have relatedRequestId set)
// Those will be sent via dedicated response SSE streams
if (requestId === undefined) {
system
October 7, 2025, 12:28pm
2
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