Source Intelligence
Sweep 28 Aug 2026 · 00:00Z Build v2.1.250 478 read Stable v2.1.236 Latest v2.1.250 Next v2.1.250 Feeds RSS JSON llms.txt

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.

Reference / Feature flags

tengu_russet_plover

A Claude Code feature flag, read out of the shipped bundle. It has been in the build since v2.1.239, including the newest one read.

What it is

Artifact syntax highlighting and mermaid diagrams are now always on; three other gates were renamed and stay off.

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.239.

Presence across releases

ReleasesReadingDeclared typeDefault
2.1.245 – 2.1.250 5 releases never mined
2.1.239 – 2.1.243 5 releases in the build bool:false

A row reading never mined is a release with no archived bundle behind it. Nothing was read out of it, so nothing here says whether the name was in it. A declared type or a default is only ever what that release's own bundle stated.

Gate readings

ReleaseResolvedThis accountAnonymousCompiled default
v2.1.240 Off in both readings off off on
v2.1.239 Off in both readings off off on

Two arms, because they disagree: this account is the one account this site reads and anonymous is a baseline with no identity attached. A reading says nothing about your account, and off cannot rule out a rollout both readings sit outside of. What these readings can and cannot show.

Changelog entries naming it

  1. v2.1.240Saving a default effort level can now scope it to one model

    Your saved default effort could apply per model instead of everywhere, but that is off.

    gate cited by this entry

  2. v2.1.239Three feature gates renamed, three retired

    Artifact syntax highlighting and mermaid diagrams are now always on; three other gates were renamed and stay off.

    gate cited by this entry

  3. v2.1.239Per-model effort level in settings, behind a gate

    You could set an effort level per model in settings, but the lookup is gated off.

    gate cited by this entry

Documentation pages

None of Anthropic's documentation pages this site has a copy of carries this name.

Names beside it

Every feature flag in the inventory starting tengu_russet, up to twelve of them.

tengu_russet_linnetNo description from anybody. 2.1.196 tengu_russet_pergolaA productivity-skills switch is named in the artifact code but nothing reads it. never mined

Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the feature flag does. All feature flags.