Overview

Essential is the first declarative blockchain protocol, implementing the declarative principles in a decentralized, permissionless system. The protocol is designed around the concept of blocks as pure state mutations.

State mutations are introduced as solutions provided by solvers. A solver could be:

• A third-party entity competing to find optimal solutions, or
• A centralized program (such as a server, front-end app, or wallet) providing solutions for a specific application.

In contrast to solutions in an imperative system, which consist of a sequence of ordered transactions, solutions in a declarative system are merely lists of state mutations.

From Solutions to State

Validation is the process by which solutions become state:

• A solution is considered valid if it satisfies all the contracts whose state it mutates.
• Only valid solutions are then considered for inclusion in the next block.

Inclusion and Bidding Mechanism

Inclusion in the next block happens via an out-of-protocol mechanism where solvers bid for inclusion with a solution aggregator (similar to a block builder). These bids for inclusion are expressed as constraints on state. The protocol itself, however, only concerns itself with the validity of solutions. Optimality is driven by auction dynamics at both the application and solution aggregation level.

In the following section, we will explore how contracts are structured to define conditions under which their state can be mutated.