Oracle Quickstart

What is an Oracle?

Within blockchain and smart contract ecosystems, an oracle acts as a gateway, bridging on-chain actions with off-chain information. By offering data that smart contracts inherently lack access to, oracles facilitate these contracts to interact and adapt based on real-world occurrences.

Upshot Oracle

The Upshot Oracle is tailored to fetch signed asset valuations. Given the unique demands of NFTs and other blockchain assets, having a reliable and secure method for getting appraisals is crucial.

On Ethereum mainnet, the Upshot Oracle can be found at address: 0x7fcac70760debe52e705b70cd9fd5f85b2b19501

Key Offerings

Signed Asset Appraisals
Signed Index Prices

Implementation Guide

Make a request to the Upshot API for a specific set of assets using the API's signed asset appraisals endpoint.
The result will be an array of authenticated messages from the API that you can then use to construct a verifiable transaction on-chain using the UpshotOracle.sol contract.
Using your client contract, call the decodeTokenPrices function on the upshot Oracle

const sdk = require('api')('@upshot/v1.0#2io9j2lll40n04q');

sdk.auth('api_key');
sdk.getSignedAssetAppraisals({asset_ids: '0xb47e3cd837ddf8e4c57f05d70ab865de6e193bbb%2F1'})
  .then(({ data }) => console.log(data))
  .catch(err => console.error(err));

pragma solidity ^0.8.0;

struct PriceData { 
    bytes signature;
    uint256 nonce;
    address nft; 
    uint96 timestamp;
    address token; 
    uint96 expiration;
    uint256 nftId;
    uint256 price; 
    bytes extraData;
}

interface IUpshotOracle {
    error UpshotOracleInvalidPriceTime();
    error UpshotOracleInvalidSigner();
    /**
     * @notice Decode the token prices from the encoded upshot price data
     */
    function decodeTokenPrices(
        PriceData[] calldata priceData
    ) external returns (uint256[] memory tokenPrices);
}


contract YourContract {
    IUpshotOracle public upshotOracle;

    constructor(address _upshotOracleAddress) {
        upshotOracle = IUpshotOracle(_upshotOracleAddress);
    }

    function yourFunction(PriceData[] calldata p) external {
      // ... do some stuff

      try upshotOracle.decodeTokenPrices(p) returns (uint256[] memory tokenPrices) {
        // if the code gets to here then the data is valid
        // and the tokenPrices array contains the signed prices from the PriceData[]
        // in the items in the same order as the data in the PriceData[] array
        // ... do something with tokenPrices
        
        	uint256 example = tokenPrices[0];
        
        } catch (bytes memory reason)  {
            bytes4 errCode = bytes4(reason);
            if (errCode == IUpshotOracle.UpshotOracleInvalidPriceTime.selector) {
                // ... handle error that the price appraisal has expired its validity
            } else if (errCode == IUpshotOracle.UpshotOracleInvalidSigner.selector) {
                // ... handle error that the price appraisal either was not formatted correctly
                // or the signature was not signed by the real price appraiser API
            }
        }
    }
}