Deploy Proxy and Install Plugin

Context

In this guide, we will show you how to programmatically deploy a proxy and install the official Sablier plugin.

While the proxy architecture offers many benefits, it presents us with a challenge in a particular circumstance. When a recipient cancels a stream, the protocol transfers the sender's refund to the proxy contract. To improve the user experience, we wrote a specialized plugin that can be installed on the proxy contract to auto-forward the refunded assets back to the original user.

caution

The code in this guide is not production-ready, and is implemented in a simplistic manner for the purpose of learning.

Set up a contract

Declare the Solidity version used to compile the contract:

// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity >=0.8.19;

Import the relevant symbols from @sablier/v2-periphery:

import { IPRBProxy, IPRBProxyRegistry } from "@sablier/v2-periphery/src/types/Proxy.sol";
import { ISablierV2ProxyPlugin } from "@sablier/v2-periphery/src/interfaces/ISablierV2ProxyPlugin.sol";

Create a contract called ProxyDeployerAndPluginInstaller, and declare a constant PROXY_REGISTRY of type IPRBProxyRegistry and an immutable variable proxyPlugin of type ISablierV2ProxyPlugin:

contract ProxyDeployerAndPluginInstaller {
    IPRBProxyRegistry public constant PROXY_REGISTRY = IPRBProxyRegistry(0x584009E9eDe26e212182c9745F5c000191296a78);
    ISablierV2ProxyPlugin public immutable proxyPlugin;
}

info

The PRBProxyRegistry contract is deployed at the same address across all chains. You can see a list of all deployments here.

Initialization

To initialize the address of the Sablier ProxyPlugin contract, you first need to grab its address from the Deployment Addresses page. Once you have obtained it, pass it to the constructor of the deployer contract:

constructor(ISablierV2ProxyPlugin proxyPlugin_) {
    proxyPlugin = proxyPlugin_;
}

Function definition

Define a function called deployProxyAndInstallPlugin which returns the proxy of the contract itself:

function deployProxyAndInstallPlugin() public returns (IPRBProxy proxy) {
    // ...
}

Steps

First, check if the proxy already exists:

// Get the proxy for this contract
proxy = PROXY_REGISTRY.getProxy({ user: address(this) });

Second, deploy the proxy and install the plugin if the proxy doesn't exist, or otherwise just install the plugin:

if (address(proxy) == address(0)) {
    // If a proxy doesn't exist, deploy one and install the plugin
    proxy = PROXY_REGISTRY.deployAndInstallPlugin({ plugin: proxyPlugin });
} else {
    // If the proxy exists, then just install the plugin.
    PROXY_REGISTRY.installPlugin({ plugin: proxyPlugin });
}

note

There can only be one PRBProxy contract per address. If you try to deploy a proxy for an address that already has one, the transaction will revert.

The complete deployer contract

Below you can see the complete functioning code: a contract that queries the registry, deploys the proxy if it doesn't exist, and installs the plugin. You can access the code on GitHub through this link.

Proxy Deployer and Plugin Installer

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