CLAUDE_CODE_WALNUT_SPIRE
A Claude Code environment variable, read out of the shipped bundle. It was in the build from v2.1.207 and was gone by v2.1.269.
Plugin eval checks your credentials first and aborts instead of failing every case.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.233.
In the changelogs
7Releases whose published page names CLAUDE_CODE_WALNUT_SPIRE.
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v2.1.235
plugin evalgains --eval-dir and a manifest eval directory, still early accessplugin eval gets a configurable case directory via --eval-dir or a manifest key, still gated as early access
found in this entry's text
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v2.1.233
Plugin eval checks your credentials before running any case
Plugin eval checks your credentials first and aborts instead of failing every case.
found in this entry's text
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v2.1.233
Grader summaries in plugin eval are scrubbed before truncation
Grader summaries in plugin eval are stripped of escape characters before printing.
found in this entry's text
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v2.1.233
Plugin subcommand help now comes from one table, with eval commands hidden
Plugin subcommand help now comes from one table, with eval commands hidden by default.
found in this entry's text
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v2.1.233
Plugin eval tells the model the env var that turns it on
Setting CLAUDE_CODE_WALNUT_SPIRE=1 turns on the early-access plugin eval command.
named in this entry, found in this entry's text
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v2.1.233
The built-in guide agent can answer questions about plugin eval and /skill-doctor offline
The built-in guide agent can now answer about plugin eval and /skill-doctor from bundled reference text.
found in this entry's text
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v2.1.207
Walnut Spire (
plugin evalGeneral Availability) [In Development]found in this entry's text
First cited
2The earliest release whose published evidence quoted CLAUDE_CODE_WALNUT_SPIRE was v2.1.207, 10 Jul 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table below.
Presence across releases
2Build by build
90One row per release since the first build this name was read out of. Absent means the build was read and the name was not in it, never mined means no bundle for that release was ever archived, and a declared type or a default is only ever what that release's own bundle stated.
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 environment variable does. All environment variables.