pools

curve-contract/contracts/pools

Deployed Curve pool contracts.

Subdirectories

Each subdirectory holds contracts and other files specific to a single Curve pool.

• 3pool: Tri-pool
• busd: BUSD pool, with lending on yearn.finance
• compound: Compound pool, with lending on Compound
• gusd: GUSD metapool
• hbtc: hBTC pool
• husd: HUSD metapool
• pax: PAX pool, with lending on yearn.finance
• ren: RenBTC pool
• sbtc: sBTC pool
• snow: Snow pool, for swaps between yVault tokens
• susd: sUSD pool
• usdk: USDK metapool
• usdn: USDN metapool
• usdt: USDT pool, with lending on Compound
• y: Y pool, with lending on yearn.finance

Development

Adding a New Pool

• Contracts for a new pool should be placed in their own subdirectory using the same name as is given on the website.
• The LP token contract does not need to be included, unless it deviates from the standard contracts within contracts/testing
• Each subdirectory must contain a pooldata.json file using the structure given below. This is required in order to initialize fixtures when running the test suite.

{
    "lp_contract": "CurveTokenV1",       // LP token contract to use with this pool, from `contracts/tokens`
    "wrapped_contract": "yERC20",        // mock wrapped coin contract to use, from `contracts/testing`

    // constructor settings for the LP token - required for deployment
    "lp_constructor": {
        "symbol": "",
        "name": ""
    },
    // constructor settings for the pool - required for deployment
    "swap_constructor": {
        "_A": 200,
        "_fee": 4000000,
        "_admin_fee": 0
    },
    // each list item represents 1 swappable coin within the pool
    "coins": [
        {
            // required fields
            "decimals": 18,               // number of decimal places for the underlying coin
            "tethered": false,            // does the token contract return `None` on a successful transfer/approve?
            "wrapped": true,              // is wrapping used for this coin?
            "wrapped_decimals": 18,       // decimal places for the wrapped coin - can be omitted if wrapped == false
            // optional fields
            "name": "",                   // underlying coin name
            "withdrawal_fee": 0,          // fee applied when converting wrapped to underlying, expressed in bps
            "underlying_address": "0x00", // underlying coin mainnet deployment address, used in forked tests
            "wrapped_address": "0x00"     // wrapped coin mainnet deployment address
        },
    ]
}

Metapools

A metapool is a pool where a stablecoin is paired against the LP token from another pool.

The pooldata.json for a metapool is similar to that of a regular pool:

{
    "lp_contract": "CurveContractV2",  // LP token contract to use with this pool, from `contracts/tokens`
    "base_pool": "3pool",              // Name for the related base pool
    "coins": [
        {
            // the first coin in the metapool is an unwrapped stablecoin
            "decimals": 18,
            "tethered": false,
            "wrapped": false
        },
        {
            // the second coin in the metapool is the LP token from the base pool
            "decimals": 18,
            "wrapped": false,
            "base_pool_token": true
        }
    ]

}