CLAUDE_CODE_PROMPT_CACHE_TTL

A Claude Code environment variable, read out of the shipped bundle. It has been in the build since v2.1.242, including the newest one read.

Releases whose published page names CLAUDE_CODE_PROMPT_CACHE_TTL.

1. v2.1.300 14 Oct 2026
   New CLAUDE_CODE_MESSAGES_PROMPT_CACHE_TTL environment variable

   A new environment variable, CLAUDE_CODE_MESSAGES_PROMPT_CACHE_TTL, sits alongside the existing prompt cache lifetime settings

   found in this entry's text, named in this entry

2. v2.1.300 14 Oct 2026
   Main-conversation prompt caching can be forced to five minutes

   Setting CLAUDE_CODE_MESSAGES_PROMPT_CACHE_TTL to 5m makes the main conversation's prompt cache last 5 minutes instead of the usual length

   found in this entry's text

3. v2.1.248 27 Aug 2026
   Agents can set their own prompt cache lifetime in frontmatter

   An agent file can set its own prompt cache lifetime under experimental cacheTtl.

   found in this entry's text

4. v2.1.242 24 Aug 2026
   Prompt cache lifetime is now configurable

   You can pin the prompt cache to five minutes or an hour, separately for subagents.

   named in this entry, found in this entry's text

No release's published evidence quotes this name. The ledger indexes the Evidence lines of every changelog on this site, so this says nobody here has ever quoted it; it says nothing about how old the name is.

One 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.