CLAUDE_CODE_RESUME_CACHE_WARM
A Claude Code environment variable, read out of the shipped bundle. It has been in the build since v2.1.318, including the newest one read.
Claude Code recognises CLAUDE_CODE_RESUME_CACHE_WARM and lets a cache-warming request run when you resume a session
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.318.
In the changelogs
2Releases whose published page names CLAUDE_CODE_RESUME_CACHE_WARM.
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v2.1.318
New
CLAUDE_CODE_RESUME_CACHE_WARMvariable and cache warming on resumeClaude Code recognises
CLAUDE_CODE_RESUME_CACHE_WARMand lets a cache-warming request run when you resume a sessionfound in this entry's text, named in this entry
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v2.1.318
Resumed remote sessions can warm the prompt cache before your first message
After a remote session resumes, Claude Code can send a small background request so the first reply is faster; it is off unless enabled
found in this entry's text
First cited
1The earliest release whose published evidence quoted CLAUDE_CODE_RESUME_CACHE_WARM was v2.1.318, 3 Nov 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
1Build by build
1One 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.