Chainlink + Curve LP Token Feed
Chainlink Curve Pool Oracle implementation
🔎 High-level Overview
The implementation for the Oracle is done according to the Curve - Chainlink Oracle implementation guide.
In order to compute the price, we need the Chainlink Data Feeds for each LP token. For example, in order to price the pool in USD, we need the price feeds for each token within the pool in USD, which in this case would be DAI/USD, USDT/USD, and USDC/USD. We also need the addresses of the Curve 3 Pool, the address of the Curve 3 LP Token, and the Curve LUSD Pool.
The resulting spot price is converted to a per-second rate that is used by the Relayer to push values to Collybus.
List of Curve Pool Oracles:
LUSD3CRVValueProvider- LUSD Curve Pool Oracle.
🐣 Initialization
These are the parameters needed to build the LUSD3CRVValueProvider Oracle:
curve3Pool- Address of the Curve 3 PoolcurveLUSD3Pool- Address of the LUSD Curve PoolchainlinkLUSD- Address of the LUSD Chainlink Data FeedchainlinkUSDC- Address of the USDC Chainlink Data FeedchainlinkDAI- Address of the DAI Chainlink Data FeedchainlinkUSDT- Address of the USDT Chainlink Data Feed
All of the initial parameters are immutable which means once they are set they can not be modified.
🌈 Execution Flow
Each specific oracle implementation must define the Oracle.getValue() function. This function is called when the global execution flow is triggered by the Relayer.
In order to compute the price we follow a few steps:
We query all the Chainlink Data Feeds for the latest price for the tokens within the 3 Pool(USDC, DAI, USDT) and find the smallest value.
Retrieve the virtual price for the Curve 3 Token and multiply it by the minimum value obtained in step 1.
Compute the minimum between the value obtained in step 2 and the LUSD price retrieved from the Chainlink Data feed.
Compute the final price by retrieving the virtual price for the LUSD Curve Pool LP Token and multiplying it by the value obtained in step 3.
📑 Public Methods
These methods can be called by anyone:
decimalsUSDC
Decimals for the Chainlink Data Feed price.
decimalsDAI
Decimals for the Chainlink Data Feed price.
decimalsUSDT
Decimals for the Chainlink Data Feed price.
decimalsLUSD
Decimals for the Chainlink Data Feed price.
curve3Pool
Address of the Curve 3 Pool.
curveLUSD3Pool
Address of the Curve LUSD 3 Pool.
chainlinkLUSD
Address of the Chainlink Data Feed.
chainlinkUSDC
Address of the Chainlink Data Feed.
chainlinkDAI
Address of the Chainlink Data Feed.
chainlinkUSDT
Address of the Chainlink Data Feed.
getValue
Computes and returns the spot price.
description
Returns the description of the Oracle.
📘 References
Last updated