Plugins now get a dedicated persistent data directory at ~/.claude/plugins/data/{id}/, accessible via the CLAUDE_PLUGIN_DATA environment variable and the ${CLAUDE_PLUGIN_DATA} template in plugin configs.
Details
Each plugin receives its own data directory, created automatically
The directory persists across plugin updates and sessions
On plugin uninstall, users are prompted: "Delete it along with the plugin?" with the data directory path shown
Use --keep-data flag with uninstall to preserve the data directory
Evidence
Plugin data path helper (search for "CLAUDE_PLUGIN_DATA") — new env var injected into plugin processes; --keep-data CLI option (search for "--keep-data")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeAdded ${CLAUDE_PLUGIN_DATA} variable for plugin persistent state that survives plugin updates; /plugin uninstall prompts before deleting it
