Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.221 Home All releases olderv2.1.220 v2.1.222newer

New "prototype" skill, present in the bundle but hard-disabled

Not switched on
Useful3 Signal4
Skills Notable

A built-in "prototype" skill for one-page HTML mockups ships but is hard-disabled.

The prototype skill builds and republishes a single HTML page artifact, but its enable check always returns false.

prototype
What

A built-in skill registered as name: "prototype" ships in this build but is switched off, so it never appears in the skill menu.

Details
  • SKILL.md tells Claude to run a short intake ("two to four at most, in one short message"), state assumptions, load the artifact-design skill, write one self-contained HTML page in the scratchpad directory, and publish it with the Artifact tool
  • iteration republishes the SAME file so the URL and version history carry forward
  • registration passes isEnabled: Lgo, and function Lgo() { return !1; } is a build constant, so the skill is unreachable on 2.1.221 unless a later build changes that helper
  • also exported as isPrototypeEnabled
Evidence

menuDescription: "Prototype an idea as a working Artifact"

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.221 →