Static (arc.static)

Automatically build and deploy your static assets

Architect projects support a public/ directory in the root of your project for static assets. The public/ directory typically includes static assets such as images, styles, and scripts required in your front-end workflows.

Anything in public/ directory is available at http://localhost:3333/_static/ when running in the sandbox.

For production and staging environments, Architect can have staging and production S3 buckets for file syncing from the public/ folder - they'll be available at once deployed.

The arc.static helper resolves URL paths for your static assets, so you're requesting the right file from every environment.

And if you've enabled fingerprinting, arc.static also resolves the unique fingerprinted filename in staging and production environments.


Given the following .arc file:


staging my-unique-bucket-staging
production my-unique-bucket

Running npx create will generate staging and production S3 buckets.

⚠️ Warning: S3 buckets are globally unique to all of AWS so you may have to try a few names.


To enable file fingerprinting, add fingerprint true to your @static pragma, e.g.:

staging my-unique-bucket-staging
production my-unique-bucket
fingerprint true

Working Locally with public/

Running npx sandbox kicks up a sandbox web server (more here about working locally). The folder public/ at the root of your project will be mounted at /_static when you run the web server with npx sandbox.

Any file added to this public/ folder will be served (along with any HTTP functions you've defined).

Most frontend JavaScript workflows involve some sort of build step, so the public/ folder is a staging area for those build artifacts (along with whatever else you'd like to use it for, of course).

The simplest possible build script defined in package.json:

  "build": "cp -r src/shared/client public",
  "start": "npm run build && npx sandbox"

Running the script defined above with npm run build just blindly copies files from src/shared/client to public/. (This could definitely be enhanced by using a module bundler like Browserify, Parcel or Webpack depending on your needs!)

Running npm start builds the JS and starts a local web server on http://localhost:3333 for previewing.

Deploying public/

Running npx deploy copies public/ to the staging bucket. (If you want to version these assets in S3, you can enable that feature in the AWS Console.)

Alternately you could consider these build artifacts (which they are) and treat your version control system as the place to manage versions (which it is). 😶

Running ARC_DEPLOY=production npx deploy copies public/ to the production bucket.

And, of course, it would be wise to use both of these S3 buckets as origins for your CDN (we're partial to AWS CloudFront).

🏌️‍♀️ Protip: npx deploy static will deploy the static assets only

⛳️ Protip #2: npx deploy [static] --delete will remove files from the bucket that are no longer locally present


Isolation is key to creating a continuous delivery pipeline. It's good to work on our local machines, deploy to a staging environment, and promote to production with total confidence that the system is only improving. Static assets are no different!

As such, there are three environments you need to be concerned about for addressing your static assets:

  • Local:


  • Staging:

    https://<staging bucket>.s3.<aws region><asset>

  • Production:

    https://<production bucket>.s3.<aws region><asset>

This is an example production URL from a testing app:

Calling static URLs

@architect/functions bundles a helper function for HTTP route handlers that disambiguates URLs called arc.static. It accepts a relative path and returns the URL appropriate for the environment it's being invoked in.

// src/http/get-index/index.js
let arc = require('@architect/functions')
let static = arc.static

exports.handler = async function http(req) {
  let body = `
    <!doctype html>
        <title>This is fun!</title>
        <link rel=stylesheet type=text/css href=${static('/main.css')}>
      <body>Hello ƛ</body>
      <script src=${static('main.js')}></script>
  return {
    type: 'text/html',

Ignoring files from public/

You can instruct Architect to ignore files from your public/ directory with the ignore directive, like so:

staging my-unique-bucket-staging
production my-unique-bucket

This works with a simple string search, so if you ignore foo, all filenames containing foo (or files with paths containing foo) will be ignored.

By default, Architect ignores .DS_Store, node_modules, and files

See the static reference for more details.

Next: Single Page Apps