# Runtime
URL: https://lsd.tools/docs/api-runtime
Updated: 2026-07-17

You author against `lsdtools` in any local Python, but packages **run inside the installed LSD
product** — the MSI-installed runtime (or a dev build), which carries the pacman-built `pyarrow`,
`numpy`, and GTK your packages need. `find_runtime()` discovers that install and returns a `Runtime`
describing it: its install dir, the CLI and GUI launchers, and the bundled interpreter. `API_VERSION`
reports the public API version your package was built against.

## Usage

```python
from lsdtools import find_runtime, API_VERSION

rt = find_runtime()
print(rt.cli, API_VERSION)
# → C:\Program Files\LSD Desktop\LSDCli.exe 1.0
```

## Where to start

**Learn** — [Install LSD](/docs/start-install)

**API** — [Engine](/docs/api-engine) · [CLI commands](/docs/api-cli) · [lsdtools API reference](/docs/api-index)