{"version":"2.1.265","anchor":"artifact-db-mcp-switch-latched-behind-tengu-cobalt-plinth","canonical_anchor":"mcp-config-building-gets-a-new-five-class-entries-cache-g","heading":"MCP config building gets a cache, off by default","tier":"soon","area":"Artifacts","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.265\/e\/artifact-db-mcp-switch-latched-behind-tengu-cobalt-plinth","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.265","markdown":"### MCP config building gets a cache, off by default\n\nA new gated cache for building MCP server configs exists but is switched off by default\n\n**What**\n\nClaude Code can connect to MCP (Model Context Protocol) servers, which requires building their connection configs. A new mechanism now caches that config-building work instead of redoing it every time, feeding into the existing MCP connection-management step.\n\nThis is controlled by a feature flag called the \"artifact MCP switch\" (`tengu_cobalt_plinth_loquat`). New per-session state tracks things like whether the switch has been decided (latched), whether MCP servers\/entries have already been built, and how many entry-skips have been logged. The gate decision is made once per session and reported via telemetry. When the switch is off, the cache is a no-op and config building happens as before.\n\n**Why**\n\nThe switch defaults to off, so this doesn't change current behavior yet, but it lays the groundwork to avoid rebuilding MCP server configs unnecessarily once enabled.\n\n- Flag `tengu_cobalt_plinth_loquat`: Not enough to say (read for one account on one subscription tier against v2.1.265; this account: no value returned, anonymous baseline: no value returned, compiled default: off)\n- Area: Artifacts\n- Tier: Nothing to try yet\n- Useful: 3\/5\n- Signal: 3\/5\n- Present in the build but not switched on"}