{"version":"2.1.285","anchor":"mcp-server-connect-and-resolve-helpers-on-the-session-scope","canonical_anchor":"mcp-server-connect-and-resolve-helpers-on-the-session-scope","heading":"Connecting an MCP server now fails cleanly if it leaves the session first","tier":"internal","area":"MCP","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.285\/e\/mcp-server-connect-and-resolve-helpers-on-the-session-scope","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.285","markdown":"### Connecting an MCP server now fails cleanly if it leaves the session first\n\nIf an MCP server is removed before it finishes connecting, the connection attempt now reports a failure\n\n**Unclear.** It is not clear which parts of Claude Code use these new connection steps.\n\n**What**\n\nAn MCP server is an outside program that gives Claude extra tools. Claude Code gains new internal ways to look up, wait for and connect an MCP server within a session.\n\nIf the server is removed from the session before it finishes connecting, the connection attempt now fails with a message. The message says the server left the session before it connected.\n\n**Why**\n\nParts of Claude Code, such as plugins or programs built on the SDK, can wait for an MCP server to finish connecting and get a clear result.\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 3\/5"}