# GraalVM Native Image

`ol.vips` supports Oracle GraalVM Native Image 25 or newer.

## Build requirements

* Include the native companion jar for the target platform.
* Follow the [babashka.ffi Native Image requirements](https://github.com/babashka/ffi/blob/v0.1.2/doc/guide.md#build-your-own-native-image),
  including libffi support. `ol.vips` needs libffi for C functions with variable
  argument lists.
* In addition to those options, enable `-H:+SharedArenaSupport` for stream I/O.

The `ol.vips` jar includes the resource and reflection metadata needed by
Native Image. No additional metadata is required for the bundled native
libraries or for closing image handles.

## Initialization and runtime

Initialize the Clojure namespaces at build time, as described in the
`babashka.ffi` guide. Call `v/init!` and other image functions only after the
executable starts, not at the top level of a namespace during compilation.

The bundled native libraries are extracted at runtime. The extraction directory
must be writable; set `-Dol.vips.native.cache-root=/path` to choose it.
The executable still needs the operating system’s shared libraries and, unless
linked statically, libffi.