NodeJs for Embedded device: lighter alternative to express.js

I'm looking for a lighter alternative to express.js for build up a simple rest server in embedded device (OpenWRT).

I need few feature that I'm used to inside express.js:

• a way to make rest endpoint with get, post and delete
• a way to parse the incoming request (body-parser in express)
• a way to use a basic-auth middleware

is there any choice? I tried to make it vanilla javascript but I'm not so experienced and I had problem in the basic auth middleware and in the body parser..