cow-fee

Development

Module contract code is located here. The test for it is located here.

The driver script is located at index.ts. All other code is in the ts directory. It uses Ethplorer and Blockscout APIs to determine the different tokens held by the Settlement contract. It then filters them on the basis of:

1. Swap output value, see module setup.

The program after filtering and determining which tokens to swap, posts the swap orders on the CoW OrderBook API. For all the orders that got successfully posted, it determines which of those orders require approval and sends a tx to call COWFeeModule::drip with tokens that need to be approved, and tokens that need to be swapped specifiying both the sell and buy amounts.

There are additional methods:

1. COWFeeModule::approve -- will max approve all the specified tokens to be spent by the vault relayer.
2. COWFeeModule::revoke -- will revoke the given tokens for given spenders.

Usage

Contract

Set the following env vars:

RECEIVER
TO_TOKEN
KEEPER
SETTLEMENT
APP_DATA
TARGET_SAFE
MIN_OUT

Then run the script to deploy the module:

forge script ./script/COWFeeModule.s.sol \
  --rpc-url <rpc> \
  --broadcast

Keeper

Private key for keeper needs to set with PRIVATE_KEY environment variable.

Usage: cow-fee [options]

Options:
  --network <network>                                   (choices: "mainnet", "gnosis", "arbitrum")
  --rpc-url <rpc-url>
  --max-orders <max-orders>                            Maximum number of orders to place in single drip call (default: 250)
  --buy-amount-slippage-bps <buy-amount-slippage-bps>  Tolerance to add to the quoted buyAmount (default: 100)
  --module <module>                                    COWFeeModule address
  --token-list-strategy <strategy>                     Strategy to use to get the list of tokens to swap on (choices: "explorer", "chain", default: "explorer")
  --lookback-range <n>                                 Last <n> number of blocks to check the `Trade` events for (default: 1000)
  -h, --help                                           display help for command

Directly

yarn ts-node index.ts \
  --network mainnet \
  --max-orders 250 \
  --rpc-url https://eth.llamarpc.com \
  --buy-amount-slippage-bps 100 \
  --module <module-address> \
  --token-list-strategy chain \
  --lookback-range 1000

Docker

# build the docker file
docker build -t cow-fee .
# run the container
docker run --rm \
  -e PRIVATE_KEY=$PRIVATE_KEY \
  cow-fee \
  --network mainnet \
  --max-orders 250 \
  --rpc-url https://eth.llamarpc.com \
  --buy-amount-slippage-bps 100 \
  --module <module-address> \
  --token-list-strategy chain \
  --lookback-range 1000

Module operations with cast

Enable module

cast calldata "enableModule(address)" <module-address>

use this calldata to send a transaction from a safe to itself to enable the module on that safe.

Disable module

Use the safe UI settings page to disable the module.

Tests

$ forge test -vvv --rpc-url https://eth.llamarpc.com