{"version":"2.1.295","anchor":"mcp-websocket-messages-over-a-size-cap-now-close-the-connect","canonical_anchor":"mcp-websocket-messages-over-a-size-cap-now-close-the-connect","heading":"Oversized messages from WebSocket MCP servers now close the connection","tier":"notice","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.295\/e\/mcp-websocket-messages-over-a-size-cap-now-close-the-connect","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.295","markdown":"### Oversized messages from WebSocket MCP servers now close the connection\n\nIf an MCP server connected over WebSocket sends a message above a size limit, Claude Code closes the connection without reading it\n\n**What**\n\nMCP 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.\n\nClaude 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.\n\n**Why**\n\nIf 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.\n\n- Area: MCP\n- Tier: You'll notice\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}