Often when developing complex client side apps, a simple
python -m SimpleHTTPServer can host the html. For a node backend though, a second server has to be run to host the REST api, which must be on a different domain. For example the python server is on port
8000, whereas the REST server is run on port
This will usually throw an error containing the script
Origin https://localhost:8000 is not allowed by Access-Control-Allow-Origin
This is a security measure input by web browsers to prevent cross domain scripting attacks, and is a good idea, but during development this can be a problem.
One option is to use a fully featured web server e.g. express but for rich client side applications this is generally overkill, a simpler library such as restify is ideal.
A nice option as supplied by this SO answer is to add middleware to allow certain domains access to the REST server.
For development this is a handy workaround, but for production obviously DO NOT USE!
For restify this can be inserted before your normal CRUD routes as middleware using