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Purpose

The purpose of the pricing contracts is to serve as token-price data sources for ecosystem applications. The token pricers can be found in 2 different categories: Developers may choose to adapt their preferred third-party solution for token pricing: Configured pricing modules are required for the following rules:

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Configuration

To set up the pricer contracts:
  1. Make sure you have deployed your ERC20 and your ERC721 pricer contracts, or that your third party solutions are ready to communicate with your application.
  2. Connect the pricer-contract set to your appManager. For this, only an account with the role of ruleAdministrator will be able to call the following functions in the appManager Handler: 
/**
     * @dev sets the address of the erc20 pricing contract and loads the contract.
     * @param _address ERC20 Pricing Contract address.
     */
    function setERC20PricingAddress(address _address) external ruleAdministratorOnly(appManagerAddress);

    /**
     * @dev sets the address of the nft pricing contract and loads the contract.
     * @param _address Nft Pricing Contract address.
     */
    function setNFTPricingAddress(address _address) external ruleAdministratorOnly(appManagerAddress);
Pass the addresses for your pricer contracts respectively, and you’re done!

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ERC20 Example

  • Cast command example to set the ERC20 pricer contract:
cast send $APPLICATION_HANDLER "setERC20PricingAddress(address)()" $APPLICATION_ERC20_PRICER --private-key $APP_ADMIN_PRIVATE_KEY --rpc-url $ETH_RPC_URL
  • Cast command example to set the ERC721 pricer contract:
cast send $APPLICATION_HANDLER "setNFTPricingAddress(address)()" $APPLICATION_ERC721_PRICER --private-key $APP_ADMIN_PRIVATE_KEY --rpc-url $ETH_RPC_URL
This set of contracts can be reset at any time by an ruleAdministrator. Simply follow the same steps mentioned above with the new addresses.

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Price Format

  • Price is in wei of US Dollars: 1 dollar is represented by 1 _ 10^18, and 1 cent is represented 1 _ 10^16 in these contracts. This is done to have precision over the price, and to account for the possibility of tokens with extremely low prices.
  • The price is given for a whole token:
    • For Fungible Tokens: just like regular market data outlets, the price will be given for a whole token without decimals. e.g 1 ETH.
    • For Non-Fungible-Tokens: even in the case of a fractionalized NFT, the price is still given for the whole token and not for its fractions.

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Examples:

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ERC20s

Let’s say we have the ERC20 called Frankenstein which has 18 decimals (1 Frankenstein = 1 * 10^18 wei of a Frankenstein). Let’s imagine that each Frankenstein is worth exactly $0.55 US Dollars (55 ¢). In this case, the price for the token will be 55 * 10^16.

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ERC721s

Let’s say we have the NFT collection called FrankensteinNFT. Let’s imagine that the FrankensteinNFT with Id 222 is worth exactly $500.00 US Dollars. In this case, the price for the token will be 500 * 10^18.