You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.295,
ImprovementsSection of the release
What
MCP servers are outside programs that give Claude Code extra tools. Some connect over WebSocket, a type of network connection that stays open and passes messages back and forth.
Claude Code now measures each message that arrives from a WebSocket MCP server. If a message is larger than a set limit, Claude Code does not read it. It reports an error and closes the connection. The error says the MCP server sent a WebSocket message over a given number of MiB (mebibytes, a unit of about one million bytes), and that Claude Code did not read it and closed the connection. Before, every message was read regardless of size.
Why
If you use an MCP server that sends very large messages over WebSocket, it may now be disconnected. The error message shows the limit in MiB, so you can see how far over it the server went.
