QABattle

MCP & Protocol Testing / Quiz

Transports: stdio vs Streamable HTTP

The data layer is the same; the pipe is not. stdio and Streamable HTTP fail in different ways, and one wrong byte on stdout wrecks a local server.

Difficulty
Medium
Format
Quiz
Points
150
Estimate
10 min

// MISSION BRIEF

Your Mission

MCP defines two transports. stdio moves newline-delimited JSON over a subprocess's stdin/stdout; Streamable HTTP moves it over HTTP POST with optional Server-Sent Events. Each has its own framing rules and its own failure modes. Test the pipe, not just the payload.

Scoring: equal weight per question.

// FIRST CONTACT

Battle teaser

For the stdio transport, how are MCP messages framed on the wire?

  1. AAs newline-delimited JSON on stdin/stdout; a single message must not contain embedded newlines
  2. BAs multipart HTTP bodies
  3. CAs length-prefixed binary frames
  4. DAs gRPC protobufs
Answers, scoring, hints, and the full battle stay sealed.

// SKILL TAGS

mcptransportstdiohttp-sseprotocol-testing