Massa's Autonomous Smart Contracts

Massa's Autonomous Smart Contracts address the challenges of reliability, sophistication, and centralization that plague dApps seeking to offer automated smart-contract execution on behalf of their users. These innovative smart contracts introduce the ability to self-wake, granting them the power to autonomously perform arbitrary operations. For instance, they can be programmed to trigger specific calls when predefined exchange rate targets are met in a decentralized exchange.

The Mechanism within Massa Network

Standard operations are sent to an operation pool and are executed when they are included in a block. The cost of execution is paid by the sender of the operation when the operation is executed.

Autonomous smart contracts work by emitting messages which will schedule the execution. The execution can be scheduled based on a target slot, or whenever a specific datastore entry has been written to (whether its value actually changed or not). Those messages are emitted by smart contracts, through operations sent by users or by autonomous operations. Messages are then stored in an asynchronous pool. Contrary to standard operations, the gas required by autonomous smart contracts is paid upfront, when they are scheduled.

The asynchronous pool is deterministic by nature as it’s filled with messages that ultimately come from operations included in blocks, which are processed by every node of the network. The pool has a finite size and messages are removed based on the fees and after a certain number of slots if they were not executed.

As for normal operations, the number of autonomous operations that can be executed is limited, through a maximum amount of gas. In practice, it’s possible that your message isn’t executed at the slot that you want, but in a later slot, when there is enough space to include your message. If you want your message to be included as soon as possible, the fees needs to be higher than other messages (just like standard operations).

Messages are ordered using the following formula:

$(Reverse(Ratio(msg.fee, max(msg.max_gas,1))), emission\_slot, emission\_index),$

where $emission\_index$ is an index that differentiate multiple messages created in the same slot.