Transmitters
Transmitters are offchain smart agents that watch for user-requests and submit responses, app-gateways decide the most suitable response according to the logic defined in them. The most suitable response then earns the right to execute the request onchain.
Depending upon the type the application, transmitters are often called relayers, solvers, fillers, provers or paymasters
Transmitter is an umbrella term to reference a set of smart offchain agents that respond to various user-requests with responses.