◀Table of Contents

Node.js Runtime

GraalVM can run unmodified Node.js applications. Applications can freely import and use NPM packages, including native ones.

For the differences between running the node native launcher and accessing Node.js/npm modules/ECMAScript modules from a Java Context, see NodeJSVSJavaScriptContext.

Installing Node.js Component

Since GraalVM 21.1, the Node.js support is packaged in a separate GraalVM component. It can be installed with the GraalVM Updater.

$JAVA_HOME/bin/gu install nodejs

This installs the node and npm binaries in the $JAVA_HOME/bin directory.

Polyglot Support in Node.js

The Node.js component is able to use the polyglot language interoperability (flag: --polyglot) with other installed polyglot languages. This feature is available by default in JVM mode (flag: --jvm). For polyglot access to the Ruby language, you can e.g. use this command:

$JAVA_HOME/bin/node --jvm --polyglot -e 'var array = Polyglot.eval("ruby", "[1,2,42,4]"); console.log(array[2]);'

To use the polyglot capabilities of node in the native mode (flag: --native), the libpolyglot needs to be rebuilt first. For this, the native-image component and the other languages need to be installed first, before the image can be rebuilt:

$JAVA_HOME/bin/gu install native-image
$JAVA_HOME/bin/gu rebuild-images libpolyglot

After a successfull rebuild, the polyglot access is also available in the --native mode:

$JAVA_HOME/bin/node --native --polyglot -e 'var array = Polyglot.eval("ruby", "[1,2,42,4]"); console.log(array[2]);'

Running Node.js Applications

To run Node.js-based applications, use the node launcher in the GraalVM distribution:

$JAVA_HOME/bin/node [options] [filename] [args]

GraalVM’s Node.js runtime is based on a recent version of Node.js, and runs the GraalVM JavaScript engine instead of Google V8. Thus, some internal features (e.g., VM-internal statistics, configuration, profiling, debugging, etc.) are unsupported, or supported with potentially different behavior.

The node command is largely compatible with Node.js, and features additional GraalVM-specific functionalities (e.g., interoperability with Java and all other GraalVM languages). A list of available options can be obtained with node --help.

Installing Packages Using npm

To install a Node.js package, you can use the npm launcher from the GraalVM’s /bin folder. The npm command is equivalent to the default NPM command, and supports most of its options.

An NPM package can be installed with:

$JAVA_HOME/bin/npm install <package>

As the npm command of GraalVM is largely compatible with NPM, packages will be installed in the node_modules folder, as expected.

Installing npm Packages Globally

Node packages can be installed globally using npm and the -g option. By default, npm installs global packages (links to their executables) in the path where the node executable is installed, typically NODE/bin. In GraalVM, while there is a node executable in JAVA_HOME/bin, this is just a link to the actual executable in the JAVA_HOME/jre/languages/js/bin folder. That folder is where global packages are installed. You might want to add that directory to your $PATH if you regularly use globally installed packages, especially their command line interfaces.

Another option is to specify the global installation folder of npm by setting the $PREFIX environment variable, or by specifying the --prefix option when running npm install. For example, the following command will install global packages in the /foo/bar folder:

$JAVA_HOME/bin/npm install --prefix /foo/bar -g <package>

More details about prefix can be found in the official NPM documentation.