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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 v2.1.268 ·

MCP tool-schema meta-validator now loaded lazily via dynamic chunk import

MCP's tool-schema validator is now loaded lazily from a separate bundled chunk instead of built upfront

TierUnder the hoodhow much it should matter to you
Useful1my rating, 1 to 5
Signal1worth watching, 1 to 5
AreaMCPwhat it touches
KindInternal Changesin v2.1.268,
Under the hood

MCP's tool-schema validator is now loaded lazily from a separate bundled chunk instead of built upfront

What

When Claude Code checks that an MCP (Model Context Protocol) server's tool definitions conform to the JSON Schema draft 2020-12 standard, it now loads the validator function lazily from a separate bundled chunk of code, rather than constructing the validator instance directly every time.

Why

This is an internal implementation change to how the validator is obtained; if that validator ever fails to load, tool schema checks fail open (meaning they don't block the tool from being used), so the practical behavior for users should stay the same.

How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtWhether this lazy-loading change has any user-visible effect beyond internal structure is not stated.

See this entry in the whole of v2.1.268 →

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