tapTransport.ts•1.8 kB
import { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
import { JSONRPCMessage } from "@modelcontextprotocol/sdk/types.js";
type TransportEvent =
| {
type: "close";
}
| {
type: "onclose";
}
| {
type: "onerror";
error: Error;
}
| {
type: "onmessage";
message: JSONRPCMessage;
}
| {
type: "send";
message: JSONRPCMessage;
}
| {
type: "start";
};
export const tapTransport = (
transport: Transport,
eventHandler: (event: TransportEvent) => void,
) => {
const originalClose = transport.close.bind(transport);
const originalOnClose = transport.onclose?.bind(transport);
const originalOnError = transport.onerror?.bind(transport);
const originalOnMessage = transport.onmessage?.bind(transport);
const originalSend = transport.send.bind(transport);
const originalStart = transport.start.bind(transport);
transport.close = async () => {
eventHandler({
type: "close",
});
return originalClose?.();
};
transport.onclose = async () => {
eventHandler({
type: "onclose",
});
return originalOnClose?.();
};
transport.onerror = async (error: Error) => {
eventHandler({
type: "onerror",
error,
});
return originalOnError?.(error);
};
transport.onmessage = async (message: JSONRPCMessage) => {
eventHandler({
type: "onmessage",
message,
});
return originalOnMessage?.(message);
};
transport.send = async (message: JSONRPCMessage) => {
eventHandler({
type: "send",
message,
});
return originalSend?.(message);
};
transport.start = async () => {
eventHandler({
type: "start",
});
return originalStart?.();
};
return transport;
};