Environment & storage

Everything jrt installs lives in one directory. A few environment variables change its behaviour.

Environment variables

Variable	Purpose
`JRT_HOME`	State directory for runtimes, tools, caches, registry and shims. Defaults to `<user config dir>/JervisRuntime`.
`JRT_OFFLINE`	`1` refuses all network access; installed runtimes and materialized tools keep working. See Offline mode.
`JRT_SHIM_DEPTH`	Set internally to bound nested shim re-entry. You normally never set it.

Installer-only variables (JRT_VERSION, JRT_INSTALL_DIR, JRT_RELEASE_URL) are described in Installation.

OS	Path
Windows	`%APPDATA%\JervisRuntime`
macOS	`~/Library/Application Support/JervisRuntime`
Linux	`$XDG_CONFIG_HOME/JervisRuntime` (usually `~/.config/JervisRuntime`)

shell

jrt storage            # prints "JRT home: …" and usage per area

Entry	Contents
`registry.json`	Registered tools with their locked versions, policies and integrity data.
`compatibility.json`	Your local known-good rules.
`tools/`	Materialized tools, one directory per package version × runtime.
`package-cache/`	Shared downloads (npm, PyPI, Go modules, Cargo, NuGet, Maven, Bun, RubyGems).
`runtime-state/`	Runtime-scoped state such as rustup and Bun globals, kept away from your own setup.
`shims/`	Shims, when enabled.
`keys/`	Publisher keys created with `jrt compat keygen`.