promptCacheTtl
A Claude Code settings key, read out of the shipped bundle. It has been in the build since v2.1.242, including the newest one read.
What it is
Choose the [prompt cache lifetime](/docs/en/prompt-caching#cache-lifetime) for the main conversation
Anthropic's own wording. Read off Claude Code settings reference, captured 2026-08-28.
Presence across releases
| Releases | Reading | Declared type | Default |
|---|---|---|---|
| 2.1.245 – 2.1.251 6 releases | never mined | — | — |
| 2.1.242 – 2.1.243 2 releases | in the build | — | — |
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.
Changelog entries naming it
-
v2.1.242Prompt cache lifetime is now configurable
You can pin the prompt cache to five minutes or an hour, separately for subagents.
named in this entry
Documentation pages
- Claude Code settings reference reference table Claude Code CLI
- Track cost and usage mentions it Claude Code CLI
- Orchestrate teams of Claude Code sessions mentions it Claude Code CLI
- Claude Code changelog mentions it Claude Code CLI
- How Claude Code uses prompt caching mentions it Claude Code CLI
- Orchestrate subagents at scale with dynamic workflows mentions it Claude Code CLI
A reference table page is one whose own table defines this name, and it is where the description above came from. A page that mentions it carries the name somewhere in its text and may say nothing about it at all. Every page carrying it.
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 settings key does. All settings keys.