Overview
Sablier V2 is a binary smart contract system comprised of many contracts, libraries, and types, which together make Core and Periphery.
- Core provides the fundamental streaming logic of the Sablier V2 Protocol. It contains LockupLinear and LockupDynamic, which are the primary contracts that users will interact with.
- Periphery contracts interact with one or more Core contracts but are not part of the Core. They are an abstraction layer that enhance the security and the extensibility of the protocol without introducing upgradeability.
In the Sablier Interface, the Periphery is used to handle stream sender interactions, such as creating, canceling, and renouncing streams. The Core handles all stream recipient interactions, such as withdrawing from streams.
Given the permissionless nature of the Sablier Protocol, the Periphery has no special privileges and is only a fraction of possible periphery-like contracts. Users maintain the liberty to establish streams via the Core directly, although doing so renders those streams incompatible with the Sablier Interface.
The design of the Sablier smart contracts draws inspiration from the architectural principles of Uniswap.
Core
Core contains the streaming contracts LockupLinear and LockupDynamic, an NFT descriptor, and the Comptroller (an on-chain configuration module).
LockupLinear
Creates and manages Lockup streams with a linear streaming function.
LockupDynamic
Creates and manages Lockup streams with dynamic streaming functions.
NFTDescriptor
Generates the URI describing the Sablier V2 stream NFTs.
Comptroller
This contract is in charge of the Sablier V2 protocol configuration, handling such values as the protocol fees.
Periphery
The Periphery is a collection of contracts meant to make the Sablier Protocol more modular, more secure, and more extensible without introducing upgradeability. The key to all this is to use a forwarding proxy like PRBProxy.
Although this design requires users to deploy a proxy before interacting with the Sablier Protocol, the benefits are worth it. By bringing support for delegate calls to any Ethereum account, the proxy enables smooth migrations and opens the door for the implementation of features in a permissionless and backwards-compatible way.
ProxyTarget
Proxy target with stateless scripts for interacting with Sablier V2, designed to be used by stream senders.
ProxyPlugin
Proxy plugin that forwards the refunded assets to the proxy owner when the recipient cancels a stream whose sender is the proxy contract.
Recall that cancelling a stream refunds the sender the unstreamed balance of the stream.
Archive
An on-chain contract registry that keeps a record of all Sablier V2 contracts, including old deployments.