Extensions

Challenge extensions add conditions to an existing challenge. BotStopper uses them to check browser behavior without changing the challenge algorithm.

To enable an extension, add its name to the extensions field in your challenge definition:

thresholds:
  - name: mild-suspicion
    expression:
      all:
        - weight > 0
        - weight < 10
    action: CHALLENGE
    challenge:
      algorithm: fast
      difficulty: 2
      report_as: 2
      extensions:
        - css-load

This example adds the CSS loading extension to the fast challenge.

Extensions add inexpensive browser checks that can help detect scripts which only solve the challenge computation.

Available extensions

• CSS loading checks that the client requests a CSS resource from BotStopper.
• Headless browser detection examines the browser for signs of automation and requires JavaScript and WebAssembly.

For policy configuration, refer to thresholds and expressions.