Last reviewed
Correct answer: D. As an HTTP POST to the endpoint, with server-sent events available but not required.
Explanation
The principle — The request half is required and the streaming half is optional, which is the opposite of what the name suggests.
Why the key is correct — Streamable HTTP transport: Uses HTTP POST for client-to-server messages with optional Server-Sent Events for streaming capabilities. The client side is stated as a requirement: the client MUST use HTTP POST to send JSON-RPC messages.
Why the others are wrong — There is no standing channel the client writes into, streaming is not obligatory, and there is one endpoint rather than two.
Remember this — Client to server is always a POST; streaming is what may come back.
Sources — MCP first-party documentation.
Sources
“Streamable HTTP transport: Uses HTTP POST for client-to-server messages with optional Server-Sent Events for streaming capabilities.”
“The client MUST use HTTP POST to send JSON-RPC messages.”
Practise 10 questions on this topic
Take MCP Fundamentals — Timed Test 1 (10 questions) — scored instantly, explanation for every question, no login.