Example of using Keygen's licensing and distribution APIs together to only load an app's main logic for licensed users. The example below uses Keygen's demo account and is fully functional. Download the HTML file and open it in a browser.

_.sh

# Copy this snippet below and paste into a terminal to download the HTML file
# and open it in your default browser
tmp=$(mktemp /tmp/keygen-XXXXXX) && \
  curl -o "$tmp" https://gist.githubusercontent.com/ezekg/0f87abd27e60be3ffeef02c7c2829319/raw/97b71eb58dcd85383a4c8fccb8ce38c887e0eacb/index.html && \
  open "$tmp"

app.js

// This is the protected app logic that we're conditionally loading
// *only* for licensed users
alert('Hello world!')

index.html

<script>
  const KEYGEN_ACCOUNT_ID = '1fddcec8-8dd3-4d8d-9b16-215cac0f9b52' // Available at https://app.keygen.sh/settings
  const KEYGEN_PRODUCT_ID = '6962277c-e729-4bf2-96f1-edc98255675c'

  async function activateAppWithValidLicenseKey(key) {
    const res = await fetch(`https://api.keygen.sh/v1/accounts/${KEYGEN_ACCOUNT_ID}/licenses/actions/validate-key`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/vnd.api+json',
        'Accept': 'application/vnd.api+json'
      },
      body: JSON.stringify({
        meta: {
          scope: { product: KEYGEN_PRODUCT_ID },
          key
        }
      })
    })

    const { meta } = await res.json()
    if (meta.valid) {
      // Whenever the license key is valid, request our protected script using the license key
      const script = document.createElement('script')
      script.src = `https://dist.keygen.sh/v1/${KEYGEN_ACCOUNT_ID}/${KEYGEN_PRODUCT_ID}/releases/js/app.js?key=${key}`

      // Append the script to the body (which will run it)
      document.body.appendChild(script)
    } else {
      alert(`Your license is invalid: ${meta.detail}`)

      // Ask the user if they'd like to retry inputting their license key
      if (confirm('Do you want to try again?')) {
        await boopApp()
      }
    }
  }

  async function boopApp() {
    // Prompt the user for their license key - to demo a valid license
    // key, enter: test-key
    const key = prompt('Please enter your license key:')

    // Attempt to activate the app by validating the license key
    await activateAppWithValidLicenseKey(key)
  }

  boopApp()
</script>