{"version":"2.1.281","anchor":"headless-mcp-apply-redials-only-servers-whose-config-changed","canonical_anchor":"headless-mcp-apply-redials-only-servers-whose-config-changed","heading":"Headless MCP apply redials only servers whose config changed","tier":"notice","area":"MCP","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.281\/e\/headless-mcp-apply-redials-only-servers-whose-config-changed","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.281","markdown":"### Headless MCP apply redials only servers whose config changed\n\nIn SDK and headless sessions, applying MCP settings no longer reconnects to every server; it compares each server's config first\n\n**Unclear.** The finding's title says only changed servers are redialled, but its description says a server is dialled when the configs are equal, so which way the comparison goes is unsettled, and the flag is not named.\n\n**What**\n\nMCP servers are external programs that give Claude Code extra tools. A headless session runs without someone at the keyboard, for example one driven through the SDK (the library for running Claude Code from other programs). In these sessions, applying the MCP server list used to reconnect to every server. Once a flag is set, Claude Code now compares each server's configuration with the existing connection of the same name (`areMcpConfigsEqual`) and uses that comparison to decide whether to reconnect.\n\n**Why**\n\nFewer servers are reconnected when MCP settings are applied, so connections that do not need restarting are left alone.\n\n- Area: MCP\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5"}