The Calibre agent

When Calibre analyses your site, it does so using a custom analytics suite, that is powered by Google Chrome in a clean room environment.

Tests are conducted with cache disabled, with no other known network activity, on dedicated hardware.

Our agents autoscale to meet demand, and will never leave you waiting for tests to complete.

Recognising the Calibre agent

All requests that are made from the agent will have a X-Calibre: true header. This can be useful if you'd like to bypass user authentication, or allow Calibre to view a staging site. For tips on setting up authentication, read our auth guide.

Calibre agent IP addresses

We understand that sometimes you might need a little more than a HTTP header to identify Calibre’s agents. Our autoscaling agents use a single IP address per test region.

There are three options to retrieve a list of IP addresses:

  1. Agent Endpoint.
  2. Calibre's command line client has a calibre location-list command.
  3. The Node.js API exports a Agent.list() function.

These IP addresses may change from time to time, although this is not expected to occur on a regular basis.

Helpful links