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TWAP.md

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Type Name

TWAP

Description

This is a proposal for a new query type for reporting a TWAP spot price to the Tellor network. The query type will be called TWAP.

Query Parameters

The parameters of the TWAP query type will be the asset, currency, and timespan.

1. asset
    - description: Asset ID (ex: ETH)
    - value type: `string`
2. currency
    - description: selected currency (ex: USD)
    - value type: `string`
3. timespan
    - description: timespan of TWAP in seconds (ex: 86400 for one day)
    - value type: 'uint256`

Response Type

TWAP's response type is an unpacked 256 bit value with 18 decimals of precision. It's response type is measured in units of the base currency:

- abi_type: ufixed256x18 (18 decimals of precision)
- packed: false

Query Data

queryData = abi.encode("TWAP", abi.encode("eth", "usd", 86400))

Query ID

The Query ID is your new Query's unique identifier. It's important to have one because many kinds of data pass through the Tellor ecosystem.

To generate a query ID, get the bytes32 value of the keccak hash of the query data (defined above). For example, in Solidity:

keccak256(queryData)

You can use this tool to generate query IDs.

JSON Representation

The JSON representation of a TWAP query:

{
    "type": "TWAP",
    "abi": [
        {
            "type": "string",
            "name": "asset",
        },
        {
            "type": "string",
            "name": "currency",
        },
        {
            "type": "uint256",
            "name": "timespan",
        },
    ],
    "response": {
        "type": "ufixed256x18",
        "packed": false,
    }
}

Example

A working example mapping of all the various inputs and parameters to a valid queryID.

The queryData for a 7-day ETH/USD TWAP:

queryData = abi.encode("TWAP", abi.encode("eth", "usd", 604800))
queryId = keccack256(queryData)

queryData: 0x000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000004545741500000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000e0000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000a00000000000000000000000000000000000000000000000000000000000093a800000000000000000000000000000000000000000000000000000000000000003657468000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000037573640000000000000000000000000000000000000000000000000000000000

queryId: 0x854365fb961fe425304355b8caf75acd71a565544d647af25aa842da13615ac5

You can use this tool to generate query IDs.

Dispute Considerations

Note that following this guide does not prevent you from being disputed or guarantee reporters will properly put a value on-chain. Tellor is decentralized. This repo is a start to the education necessary for a fully decentralized oracle, but please focus on communication and working with reporters to prevent unneccesary disputes and at the same time encourage monitoring and punishment of bad data.

  • Multiple sources should be used whenever possible.
  • It is the reporters responsibility to ensure that the feed result is reasonable enough for a community consensus, otherwise it may be subject to dispute.
  • If a reasonable value cannot be determined, a value should not be submitted