> ## Documentation Index
> Fetch the complete documentation index at: https://www.diadata.org/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Hemi

> dApps built on Hemi can leverage DIA oracles to access up-to-date asset price information.

DIA is a cross-chain, trustless oracle network delivering verifiable price feeds for Hemi. DIA sources raw trade data directly from primary markets and computes it onchain, ensuring complete transparency and data integrity.

### Oracle Contracts

| Chain            | Contract Address                                                                                                           |
| ---------------- | -------------------------------------------------------------------------------------------------------------------------- |
| Hemi Mainnet     | [0xE609bFAF4449da0B97C0F7a54b1ea8Fb8D8FD7ED](https://explorer.hemi.xyz/address/0xE609bFAF4449da0B97C0F7a54b1ea8Fb8D8FD7ED) |
| Ethereum Mainnet | [0xCE521b52513242c5094bc56f57887BB2A05B8129](https://etherscan.io/address/0xCE521b52513242c5094bc56f57887BB2A05B8129)      |

### Oracle Configuration

|                   |    |
| ----------------- | -- |
| **Deviation (%)** | 1% |
| **Heartbeat**     | 1h |

### Available Asset Feeds

| Chain        | Price Feed | Type        | Adapter Address (AggregatorV3Interface)                                                                                            |
| :----------- | :--------- | :---------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| Hemi Mainnet | hemiBTC    | Fundamental | [0x240B2470421f16c6eb1F41db39c6156fb719Cd94](https://explorer.hemi.xyz/address/0x240B2470421f16c6eb1F41db39c6156fb719Cd94)         |
| Ethereum     | hemiBTC    | Fundamental | [0x798c4b91168f5c9a3b571722941756934135b059](https://etherscan.io/address/0x798c4b91168f5c9a3b571722941756934135b059#readContract) |
| Hemi Mainnet | satUSD     | Market      | N/A                                                                                                                                |

## How to Access Data

### getValue Method

To consume price data, you’ll need to invoke the [`getValue` method](/docs/guides/how-to-guides/fetch-price-data/solidity#solidity-library) on the oracle contract which you can access through the [DIA Oracle library](/docs/guides/how-to-guides/fetch-price-data/solidity#solidity-library) or the [interface](/docs/guides/how-to-guides/fetch-price-data/solidity#using-the-diaoraclev2-interface).

Below is an example of a contract consuming data from the oracle on Hemi Mainnet chain using the IDIAOracleV2 interface. If you pass `fairValue:hemiBTC` as the key, it will return the fair-value of hemiBTC with 8 decimal places (e.g. 100580335 is \$1.00580335) along with the Unix timestamp of the last price update.
You can also query the other values by passing the following keys to the getValue function:

* `usdValue:hemiBTC`: the price of hemiBTC in USD
* `numerator:hemiBTC`: the total BTC reserves
* `denominator:hemiBTC`: the total hemiBTC supply
* `DEX:satUSD/USD`: the price of satUSD in USD

```solidity theme={"system"}
pragma solidity ^0.8.13;

interface IDIAOracleV2 {
    function getValue(string memory) external view returns (uint128, uint128);
}

contract DIAOracleV2Consumer{

    address immutable ORACLE = 0xE609bFAF4449da0B97C0F7a54b1ea8Fb8D8FD7ED;

    function getPrice(string memory key)
    external
    view
    returns (
        uint128 latestPrice,
        uint128 timestampOfLatestPrice
    ) {
        (latestPrice, timestampOfLatestPrice) =
                 IDIAOracleV2(ORACLE).getValue(key);
    }
}
```

See the full example [here](/docs/guides/how-to-guides/fetch-price-data/solidity).

### Adapter contracts

To consume price data from our oracle, you can use the adapter smart contract located at the [adapter address](/docs/guides/chain-specific-guide/hemi#available-asset-feeds) for each asset. This will allow you to access the same methods on the `AggregatorV3Interface` such as `getRoundData` & `latestRoundData`. You can learn more [here](/docs/guides/how-to-guides/migrate-to-dia).

This is a sample contract for consuming the `hemiBTC` fundamental price feed:

```solidity theme={"system"}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

interface DiaAssetSpecificCallingConvention {
    function latestRoundData() external view returns (
        uint80 roundId,
        int256 answer,
        uint256 startedAt,
        uint256 updatedAt,
        uint80 answeredInRound
    );
}

contract DIAOracleSample {
    address hemiBTCAdapter = 0x240B2470421f16c6eb1F41db39c6156fb719Cd94;

    function getHemiBTCLatestPrice() external view returns (
        uint128 latestPrice,
        uint128 timestampOflatestPrice
    ) {
        // Call the Chainlink adapter's latestRoundData function
        (, int256 answer, , uint256 updatedAt, ) =
            DiaAssetSpecificCallingConvention(hemiBTCAdapter).latestRoundData();

        latestPrice = uint128(uint256(answer));
        timestampOflatestPrice = uint128(updatedAt);

        return (latestPrice, timestampOflatestPrice);
    }
}
```

***

## Request a Custom Oracle

DIA offers highly customizable oracles that are individually tailored to each dApp's needs. Each oracle can be customized in the following ways, including:

* Data Sources & Asset Feeds
* Pricing Methodologies
* Update Triggers (Frequency, Deviation, Heartbeat, ...etc)

Get a tailored oracle for your dApp, request one below:

<CardGroup>
  <Card title="Request Custom Oracle" href="/docs/guides/how-to-guides/request-a-custom-oracle" icon="angle-right" iconType="solid" horizontal />
</CardGroup>

## Support

For developer assistance, connect with the DIA team directly on [Discord](https://discord.gg/ZvGjVY5uvs) or [Telegram](https://t.me/diadata_org).