0.1.1 • Public • Published


a package for interoperation between Elm and BuckleScript compatible with ES6 modules


All respect to the existing bs-elm project, but since it required a script bundler, I decided to write my own that doesn't require a bundler to fit my use case.


npm install bs-elm-es6 in your console and then add "bs-elm-es6" to your bs-dependencies.


  1. (Optional) Expose the module in your, like so: open ElmES6;

  2. Define your ports type as a record, where each field is either a sendable of a type or a subscribable of a type. For example:

     type ports = 
       toElm: Elm.sendable(string),
       fromElm: Elm.subscribable(string)
  1. Get your target node and initialize your app. For example:
    [@bs.val][bs.scope "document"]
    external getElementById: string => Dom.element = "getElementById";
    let app: = 
      Elm.Main.init({ node: getElementById("elm-target") });
  1. Use your ports. There are two ways to do this.

The BuckleScript-y Way to use ports.

bs-elm-es6 exposes methods Elm.send('model, sendable('model)) and Elm.subscribe(('model => unit), subscribable('model)).

You can pipe into these methods like so:

app.ports.toElm -> Elm.send("Hello, from ReasonML.");
app.ports.fromElm -> Elm.subscribe(str => Js.log(str));

I imagine this is the primary way most users will interact with this package.

The JavaScript-y Way to use ports.

bs-elm-es6 also exposes a less-idiomatic-to-BuckleScript way to interact with Elm ports. That is, sendable('model) and subscribable('model) are both records with a function-valued field.

That is, you can literally call the object method directly in ReasonML like: app.ports.toElm.send("Hello, from ReasonML");

This is kind of a cringe-y hack and I don't imagine it will be widely used, but it may be useful if you're coming from the JavaScript/Elm world or if you want a faster refactor from JavaScript to Reason. (Plus, I really just wanted to see if something like this would work, and it does.)


There's a fully functioning, minimal example at which includes one incoming and one outgoing port. Let me know if you have any questions.

For further reading

I strongly recommend you check out my catch-all documentation on my projects. It describes how to get in touch with me if you have any questions, how to contribute code, coordinated disclosure of security vulnerabilities, and more. It will be regularly updated with any information I deem relevant to my side projects.

Most of all, feel free to get in touch! I'm delighted to hear suggestions or field questions.



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