Although domain fronting is decreasingly available, it’s still an important piece of the Tor censorship circumvention puzzle. In the new unified API, domain fronting will be just one of the multiple options with fallback mechanisms, such that as it continues to fall out of favour, we can divest without prematurely cutting off instances where it’s still necessary. To that end, we will implement the existing signaling channels—domain fronting, AMP Cache, and Amazon SQS (Simple Queue Service)1—into the new unified API. This is the issue to track the implementation of AMP Cache specifically. This is Activity 3.4 of [Project 201](https://gitlab.torproject.org/tpo/team/-/wikis/projects/project-201).