{"version":"2.1.274","anchor":"first-party-mcp-auto-auth-fallback-narrowed-to-design-server","canonical_anchor":"first-party-mcp-auto-auth-fallback-narrowed-to-design-server","heading":"First-party MCP auto-auth fallback narrowed to design servers requiring consent","tier":"internal","area":"MCP","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.274\/e\/first-party-mcp-auto-auth-fallback-narrowed-to-design-server","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.274","markdown":"### First-party MCP auto-auth fallback narrowed to design servers requiring consent\n\nAutomatic MCP re-authentication using a stored design token now only applies to \/v1\/design\/ server URLs, not other first-party servers\n\n**What**\n\nFor first-party MCP (Model Context Protocol, the system Claude Code uses to talk to external tool servers) servers, Claude Code previously had a fallback that could automatically re-authenticate using a consent-gated callback for any first-party-looking server. Now that fallback only fires when the server's URL is https, first-party, and its path starts with `\/v1\/design\/`. A separate check for what counts as a matching first-party URL was also widened to include a new `\/v1\/claude\/test\/` path, but the actual token-fallback behavior still only applies to `\/v1\/design\/` URLs.\n\n**Why**\n\nThis narrows automatic authentication so that other first-party MCP servers no longer silently pick up a stored design-related credential; only design servers get that fallback now.\n\nGate state\n\nNo sentence about `tengu_mcp_first_party_auto_auth` since nothing has been read about it yet.\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 1\/5"}