protocol
HTTP SSE (Server-Sent Events)
HTTP SSE is a standard for pushing real-time updates from a server to a client over a long-lived HTTP connection.
While stdio is ideal for local servers, remote MCP servers require a network transport. HTTP+SSE (Streamable HTTP) allows the server to stream updates (e.g., tool results) to the client over an open HTTP connection. It is unidirectional (server-to-client), and it enables MCP servers to be deployed behind standard load balancers or gateways.