{"version":"2.1.283","anchor":"new-tengu-starry-locket-gate-drops-unregistrable-mcp-servers","canonical_anchor":"new-tengu-starry-locket-gate-drops-unregistrable-mcp-servers","heading":"Synced claude.ai plugins can leave out MCP servers a terminal cannot sign in to","tier":"soon","area":"Plugins","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.283\/e\/new-tengu-starry-locket-gate-drops-unregistrable-mcp-servers","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.283","markdown":"### Synced claude.ai plugins can leave out MCP servers a terminal cannot sign in to\n\nClaude Code remembers when an MCP server offers no way for a terminal to register, and can leave such servers out of plugins synced from claude.ai\n\n**Unclear.** Exactly which plugin sources count as synced for this check is not settled.\n\n**What**\n\nMCP servers are outside programs that give Claude extra tools. Some need you to sign in with OAuth, a standard login flow, and for that the terminal must register itself with the server as a client.\n\n- Remembering the answer: when sign-in discovery finds that a server has no `registration_endpoint` and does not support client ID metadata documents, Claude Code now records the time as `registrationNotOfferedAt` in its credentials store. This recording happens without any flag.\n\n- Leaving servers out: for plugins synced from claude.ai, each HTTP or SSE MCP server with no `clientId`, no xaa setting and no credentials in its URL is checked against that record. If the record is less than 30 days old, the server is removed from the plugin and the debug log notes \"Left out MCP server\". This only happens when the flag `tengu_starry_locket` is on; its built-in default is false.\n\n- Checking again: if the record is older than 30 days, or dated in the future, the server is marked `redialToRelearnRegistration` instead. It is connected again and sign-in discovery runs fresh.\n\n- Skipping discovery: a second flag, `tengu_twinkly_prism`, skips MCP server discovery for claude.ai-synced plugins entirely.\n\nNothing has been read about `tengu_starry_locket` or `tengu_twinkly_prism` from the flag server.\n\n**Why**\n\nMCP servers from synced plugins that can never finish signing in from a terminal would stop showing up as failed sign-ins in `\/mcp`. The 30-day window means such a server is checked again later in case it starts allowing registration.\n\n- Flag `tengu_starry_locket`: Off in both readings (read for one account on one subscription tier against v2.1.283; this account: off, anonymous baseline: off, compiled default: off) These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.\n- Area: Plugins\n- Tier: Nothing to try yet\n- Useful: 2\/5\n- Signal: 3\/5"}