Unclear It is not clear what either variable does or whether setting one has any effect.
What
An environment variable is a named setting that a program receives when it starts. Claude Code keeps lists of which environment variables it passes on to sessions started through a runner or a bridge, where another program hosts and drives the session.
CLAUDE_CODE_COWORK_PLUGIN_SKILLappears for the first time.CLAUDE_RUNNER_OFFERS_NEW_MACHINEis added to several of the runner and bridge lists.
Both are only added to these lists. Nothing else about them changes.
Why
The names point to a plugin skill feature for Cowork and to a runner offering a new machine in host-driven sessions. What each variable does is not described.
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It is not clear what either variable does or whether setting one has any effect.