curve-pool-registry

Registry smart contract for Curve.fi pools.

Usage

Use the following functions to interact with this contract.

Finding Curve Pools

def pool_count() -> int128: view
def pool_list(i: int128) -> address: view

• pool_count provides the number of pools currently included in the registry.
• You may call to pool_list to obtain the address for a specific pool.

Calling with a value greater than pool_count will return a zero value.

def find_pool_for_coins(from: address, to: address, i: uint256 = 0) -> address: view

Locate a pool based on the tokens you wish to trade.

• from: Address of the token you wish to sell
• to: Address of the token you wish to buy
• i: Optional index value - if more than one pool is available for the trade, use this argument to see the n-th result

Returns a zero value if no pool is available, or i exceeds the number of available pools.

Getting Pool Information

Arrays will always have a length of 7. Trailing zero values should be ignored.

def get_pool_coins(pool: address) -> (address[8], address[8], uint256[8]): view

Get information on tradeable tokens in a pool.

Returns arrays of token addresses, underlying token addresses, and underlying token decimals.

def get_pool_info(pool: address) -> (uint256[8], uint256[8], uint256[8], uint256, uint256): view

Get information on a pool.

Returns token balances, underlying token balances, underlying token decimals, pool amplification coefficient, pool fees.

If the pool does not exist the call will revert.

def get_pool_rates(pool: address) -> uint256[8]: view

Get rates between tokens and underlying tokens.

For tokens where there is no underlying tokens, or where the underlying token cannot be swapped, the rate is given as 1e18.

Making Trades

def get_exchange_amount(pool: address, from: address, to: address, amount: uint256) -> uint256: view

Get the number of tokens that will be received in an exchange.

• pool: Pool address
• from: Address of the token you intend to sell
• to: Address of the token you intend to buy
• amount: Quantity of from to be sent in the exchange

Returns the expected amount of to to be received in the exchange, after fees.

def exchange(pool: address, from: address, to: address, amount: uint256, expected: uint256) -> bool: payable

Perform a token exchange.

• pool: Pool address
• from: Address of the token you intend to sell
• to: Address of the token you intend to buy
• amount: Quantity of from to be sent in the exchange
• expected: Minimum quantity of tokens received in order for the transaction to succeed

Prior to calling this function you must call the approve method in from, authrorizing the registry contract to transfer amount tokens.

Testing and Development

This project is written for compilation with Vyper 0.2.3.

Unit testing and development of this project is performed using Brownie.

To get started, first create and initialize a Python virtual environment. Next, install the requirements:

pip install -r requirements

You can then run the test suite:

brownie test

License

This project is licensed under the MIT license.