MCP & Protocol Testing / Scenario

The Handshake That Hung

A new MCP client connects and immediately stalls. Read the JSON-RPC trace and pin the exact lifecycle rule it violated.

Difficulty
Hard
Format
Scenario
Points
200
Estimate
15 min

// MISSION BRIEF

Your Mission

A partner team wrote a fresh MCP client. Against your server it hangs on connect, tools never load. Their logs say "server unresponsive." Your server logs tell a different story.

You have the full JSON-RPC trace. Find the lifecycle violation, and decide who is actually at fault.

// FIRST CONTACT

Battle teaser

First artifact

JSON-RPC trace (client -> server, server -> client)

Which lifecycle rules did the client break? (Select all that apply.)

  1. AIt declared a capability the server rejected
  2. BIt never sent notifications/initialized
  3. CIt used an unsupported protocolVersion
  4. DIt sent tools/list before the server responded to initialize
Answers, scoring, hints, and the full battle stay sealed.

// SKILL TAGS

mcphandshakelifecycleprotocol-testingdebugging