You'll noticeTier: how much it should matter to you
3Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
MCPArea: what it touches
Bug FixesKind: in v2.1.282,
Bug FixesSection of the release
What
An MCP server is an add-on program that gives Claude Code extra tools. A stdio server is one that runs on your machine and talks to Claude Code through its standard input and output.
When connecting, Claude Code first sends a short probe to agree on a protocol version. A slow server can miss the probe's time limit, then read the stale probe and reject the next step with an "unsupported protocol version" error. Before, Claude Code always restarted the server once without the probe.
Now, if that error names a modern version Claude Code supports, Claude Code asks the same running server again, waiting up to 3 seconds. It then connects using the modern protocol. It only restarts the server if that second request also fails.
Why
Slow-starting local MCP servers connect faster and are not restarted for no reason.
