Getting started

openOMSI Development Tools build plugins for openOMSI. A plugin is a single .oop file you drop into the game's plugins folder. You write it in Lua or in Rust; oopc compiles and packs it.

Install

Download the release for your system from the releases page and put oopc (and, if you like, the openomsi-devtools app) on your PATH. Rust plugins also need the Rust toolchain and the WebAssembly target:

rustup target add wasm32-unknown-unknown

Your first plugin (Lua)

oopc new hello --lua
cd hello
oopc build

oopc build writes dist/com.example.hello.oop. Copy it into openOMSI's plugins folder and start a map. Edit main.lua and build again to change it.

-- main.lua
omsi.on("start", function()
  omsi.message("Hello from my plugin!", 5)
end)

omsi.every(1, function()
  local kmh = omsi.var("Velocity")
  if kmh and kmh > 50 then
    omsi.message(string.format("Slow down: %.0f km/h", kmh), 1)
  end
end)

Your first plugin (Rust)

oopc new hello --rust
cd hello
oopc build

use openomsi_plugin_sdk as omsi;

omsi::plugin!(|| {
    omsi::on_start(|| {
        let _ = omsi::api::message("Hello from my plugin!", Some(5.0));
    });
});

A Rust plugin compiles to WebAssembly and runs in the game's sandbox. The SDK gives you a typed function for every API call and closures for events, timers and watches.

Signing

Make a key once, then sign your builds so players see "signed by ..." instead of a warning:

oopc keygen
oopc build --sign ~/.config/openOMSI-devtools/keys/my-openOMSI-key.oopkey