We use Conveyal's front-end JS tool-belt mastarm to build, run, and lint while developing.

To kick off a development server at http://localhost:9966:

npm start

This will use mastarm to run a browserify server at the above port along with a proxy for the back-end API, which is assumed to be running on http://localhost:4000.

To optionally substitute the default configuration, provide your own directory:

npm start -- --config /path/to/config