Ionic serve: proxy gives me 404 on request

I am trying to set up my proxies in Ionic, but so far I only get a 404 when hitting the localhost address.

This is my ionic.project:
{
"name": "MyApp",
"app_id": "",
"gulpStartupTasks": [
"sass",
"watch"
],
"watchPatterns": [
"www/**/*",
"!www/lib/**/*"
],
"proxies": [
{
"path": "/rest",
"proxyUrl": "https://www.myapi.com/rest"
},
{
"path": "/SignInEmail",
"proxyUrl": "https://www.myapi.com/SignInEmail"
}
]
}

When I run ionic serve, it shows that the two proxies where added "/rest => https://www.myapi.com/rest"

Yet, when I do a $http.get("/rest/something") it gives me a 404 http://localhost:8100/rest/something not found

Can anyone help?