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Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.265 ·

MCP config building gets a cache, off by default

A new gated cache for building MCP server configs exists but is switched off by default

TierNothing to try yethow much it should matter to you
Useful3my rating, 1 to 5
Signal3worth watching, 1 to 5
AreaArtifactswhat it touches
KindIn Developmentin v2.1.265,
Group of 2 Nothing to try yet

A new gated cache for building MCP server configs exists but is switched off by default

What

Claude 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.

This 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.

Why

The 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.

Read from
Feature flag
tengu_cobalt_plinth_loquat Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.265: off

Read once, for one account on one subscription tier, against v2.1.265. It isn't a statement about your account. What a flag value here can and cannot tell you

How sure we are
One source agreesOne thing we can check says the same as this entry.
The name it cites is new in this buildNew in this build: tengu_cobalt_plinth_loquat

See this entry in the whole of v2.1.265 →

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