Build a file-based application

A Raven application can be a single .rvn source file. Execute it directly with rvn without creating a project file or running a separate build command first.

File-based applications are useful for scripts, local automation, small command-line tools, learning exercises, and experiments that do not need project-level dependencies or configuration.

Write one source file

Create hello.rvn:

import System.*

func Main(args: string[]) {
    Console.WriteLine("Hello from Raven!")

    for argument in args {
        Console.WriteLine("Argument: ${argument}")
    }
}

Main receives command-line arguments as an ordinary .NET string array. A file-based application imports namespaces and calls .NET APIs just like a project-based Raven application.

Execute the file directly

Run the source and pass arguments after --:

rvn run hello.rvn -- Raven

The source path itself is shorthand for run:

rvn hello.rvn Raven

There is no explicit compilation or build step. rvn compiles the source into isolated temporary artifacts, runs the resulting .NET application, returns its exit code, and removes the artifacts afterward.

Use a shebang on macOS or Linux

Add a shebang as the first line:

#!/usr/bin/env rvn

Make the source executable and run it like a script:

chmod +x hello.rvn
./hello.rvn Raven

The rvn launcher must be available on PATH. In a Raven source checkout, sourcing scripts/raven-env.sh provides the repository-local launcher.

Move to a project when needed

Move the application into a .rvnproj when you need:

• several source files with an explicit project structure
• NuGet package or framework references
• target-framework, build, or publishing configuration
• analyzers, source generators, or other project extensions
• repeatable build artifacts instead of temporary execution artifacts

Continue with the getting-started guide to create a project. The checked-in samples/scripts/hello.rvn is a runnable example of this workflow.