Proxies in Foundry: Example Code

Foundry does not have the tools for interacting with Ethereum proxy contracts that Hardhat does. However, doing so is still very possible. In this repo, I've collected examples of how to deal with proxies in Foundry.

This uses TransparentProxy for now, with the ProxyAdmin contract that it requires.

The src and test directories contain some examples of manipulating UUPS proxies in tests.

Intuition

TransparentProxy is deployed by a ProxyAdmin contract. The owner of the implementation contract's functions and the owner of ProxyAdmin are the same.

deploying

Deploy a ProxyAdmin instance, with your wallet as admin
Deploy the implementation contract and get its address
Deploy the TransparentProxy, setting the ProxyAdmin as the admin

upgrading

The below example uses Hardhat on Optimism.

Deploy the new implementation contract and get its address
Get the address of the ProxyAdmin, as below
Call upgrade(PROXY_ADDR, IMPL_ADDR) on the ProxyAdmin, as below

Getting the ProxyAdmin address

Use cast storage to get the variable in Proxy's storage slot that stores the ProxyAdmin's address:

export OP_URL=$(pass keys/alchemy/optimism/endpoint)
export CONTRACT=0x10948Fd0beBb798d5eeb315c00B747D6436173b7 
export PROXY_ADMIN_SLOT=0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103
export PROXY_ADMIN=$(cast storage --rpc-url $OP_URL $CONTRACT $PROXY_ADMIN_SLOT | cut -c 1-2,27-)
echo $PROXY_ADMIN

Calling upgrade on ProxyAdmin

Using the environment already set above. $PRIVATE_KEY is the owner of the ProxyAdmin.

export PRIVATE_KEY="
export IMPL_CONTRACT="
export PROXY_CONTRACT="
cast call --rpc-url $OP_URL --private-key $PRIVATE_KEY $PROXY_ADMIN "upgrade(${PROXY_CONTRACT},${IMPL_CONTRACT})"

notes

The src directory contains https://github.com/MatinR1/UpgradeableTest/tree/master