# README
Off-chain protocols
This package defines the off-chain protocols for managing channels. These protocols are abstract rules which nodes should follow in order to reach a desired goal.
To implement the protocols, we make use of an abstraction we call the Objective. Objectives are named for the goal which the off-chain protocol aspires to achieve.
The following table shows some example objectives and their implemetation status:
| Objective type | Implemented |
|---|---|
direct-fund | x |
direct-defund | x |
virtual-fund | x |
virtual-defund | x |
challenge |
The set of objectives comprises the functional core of a go-nitro node. They expose only pure functions -- but otherwise take on as much responsibility as possible, leaving only a small amount of responsibility to an imperative shell.
Each Objective type is implemented by a Go struct implementing the Objective interface. Each instance of an Objective type will hold its own data.
The imperative shell will typically be responsible for:
- spawning new objective instances of one type or another
- reading and persisting objectives to and from a store.
- listening to peers and the blockchain for events relevant to the objective
- "updating" objectives by passing events to their
Update(event)function (an updated copy is returned) - "cranking" objectives by calling
Crank()(side effects are returned) - executing side effects