The Internet Content Adaptation Protocol (ICAP) is defined in [RFC 3507](I'm an inline-style link.

It offers a mechanism for intercepting and modifying HTTP requests and responses before they reach the HTTP client.

It can be a deceptively difficult protocol to use. This library aims to make it simple.

For an ICAP service to be useful it needs to be connected to an ICAP client. The Squid HTTP Proxy offers ICAP. That's what we use here.

To get a suitably configured Squid Proxy running use the supplied Vagrantfile.