The off-chain API
After the call for
instantiate, the blockchain may already have all information that is necessary to execute the machine. But in many cases it also needs to get input from other users. In a game for example, the user may need to insert their decisions on input drives for later processing.
In such situations, the user is called the “provider” for a certain drive. The provider will send the data through a simple HTTP call to the Cartesi Compute Node that represent them. The node will automatically add this data into the blockchain in the form of the requested input drive.
In section [...] we will give the full details of this HTTP API, but for now it is important to understand that some input drives will have a “provider” who is responsible to fill-in its data before execution. And this is done through an HTTP call to the localhost.