A demo/how-to project exists which uses this builder. It can be used as a template, or a way to verify correct usage of the following instructions.

Pushes the source to now, and builds the project.

Recommended .nowignore:

__sapper__
cypress
node_modules

Example now.json

{
  "version": 2,
    "builds": [
    { "src": "package.json", "use": "now-sapper" }
  ],
}

Useful if you are building the project on CI, and then want to just push the compiled source.

Recommended .nowignore:

__sapper__/dev
__sapper__/export
cypress
node_modules

Example now.json

{
  "version": 2,
  "builds": [
    {
      "src": "package.json",
      "use": "now-sapper",
      "config": {
        "build": false
      }
    }
  ]
}

You can change the Node.js version with the engines field.

Example package.json

{
  "engines": {
    "node": "12.x"
  }
}

Your Sapper project must be adapted to work with ZEIT Now 2.0, see https://github.com/thgh/sapper-template/commit/220307c800525633063df3e3373bc76d0e62cd86

For Express, the instance must be exported in src/server.js

const app = express()
export default app

For Polka, the handler must be exported in src/server.js

const app = polka()
export default app.handler