If you are planning to handle this separately in your production environment, then you can follow the instructions here: http://brunch.io/docs/config#-server- to create a separate brunch-server.js file which you can use to serve up your public directory as well as proxy any other non-static requests through to your Java API. You might be able to use something like this to help: https://www.npmjs.com/package/static-proxy

Thanks for the tip, but it doesn't seem to work.
I'm able to serve my static files, and I can see in the logs that my API is proxified. But I have a HTTP400 error in my brower.

Do you have any idea why this doesn't work ?

Logs :

30 May 10:51:10 - info: starting custom server
static-proxy listening at http://0.0.0.0:3333
30 May 10:51:16 - warn: custom server taking a long time to start
30 May 10:51:16 - warn: **don't forget to invoke callback()**
Requesting url >>  http://localhost:8080\myApi\myService
host: localhost:8080/myApi/

If I call http://localhost:8080\myApi\myService by myself I have a correct answer.
In my webapp, I have an error on this : http://localhost:3333/api/myService

My brunch-server.js file is :

staticProxy = require('static-proxy');

exports.startServer = (port, path, callback) => {
    staticProxy('localhost:8080/myApi/', port, 'http', [path], true, transform);
};

My config.coffee file is :

exports.config =
    server:
        path: 'brunch-server.js'
        port: 3333
        run: yes

We actually don't support older Brunches. Try migrating to ^2, that should be a piece of cake.

Oh yea, I didn't even notice the Brunch 1 reference. That would be the first thing to try. Also if you aren't invoking callback in your server function, then don't include it as a parameter.