# PERP CoinGecko-API

We will only have one endpoint which will give us details about all the pairs that perp supports.

The endpoint will be hosted on `/pairs`

For now the Example Response Looks like this:

#### Example Response

[
    {
          "ticker_id": "ETH_USDC",
          "base_currency": "ETH",
          "target_currency": "USDC",
          "last_price":"1400",      // last price of ETH in USDC
          "base_volume":"637",      // 24 hr volume in ETH
          "target_volume":"892538", // 24 hr volume in USDC
          "high":”51.3”,            // highest price in last 24hrs
          “low”:”49.2”,             // lowest price in last 24hrs
          "product_type": "Perpetual",
          "open_interest": ,
          "funding_rate": ,
          "next_funding_rate_timestamp": , // assumption that it's 1 hr in perp
    },
    ...similar objects for YFI_USDC, BTC_USDC, DOT_USDC and any future pairs
]

#### How do we get the list of all markets on perp?
We run the following command to get all AMM contract Addresses from metadata.perp.exchange.

curl 'https://metadata.perp.exchange/production.json' | jq '.layers.layer2.contracts | with_entries(select(.value.name=="Amm")) '

##### basic information

**perp team response**: amm.js can be used to query all amm market addresses and get basic information such as symbols of pairs.
https://github.com/perpetual-protocol/perp-contract-demo/blob/main/amms.js

#### How do we get the fields for each AMM ?

We now name and the contract address from above method.

##### Ticker ID / Base Currency / Target Currency / Product Type
Will be calculated from the name of the AMM. Product Type is fixed as perpetual.

##### Funding Rate / Next Funding Rate Timestamp
Funding rate will be fetched from subgraph's funding rate changed event.

We will fetch the latest event in the graph and use that as a funding rate.
We will also add `1 hour` (hardcoded) to the timestamp to get the next update timestamp.

{
  fundingRateUpdatedEvents(first: 5, orderBy: blockNumber, 
  orderDirection: desc, , where: { amm_in: 
  ["0x8d22F1a9dCe724D8c1B4c688D75f17A2fE2D32df"]}) {
    id
    amm
    rate
    underlyingPrice
    timestamp
  }
}

##### 24hr-High / 24hr-Low / Latest Price

For price data we want to query position data from the subgraph.
using the spot price data. We wil iterate over them to get the high-low details.

{
  positionChangedEvents(first: 1, orderBy: blockNumber, 
  orderDirection: desc, where: { amm_in: 
  ["0x8d22F1a9dCe724D8c1B4c688D75f17A2fE2D32df"]}) {
    id
    spotPrice
    fundingPayment
  }
}

##### Base Volume / Target Volume
We plan on using subgraph to get the all position changed events for past 24 hours for each AMM, then use the following formula

TargetVolume = sum of positionalNotional
BaseVolume = sum of (positionalNotional / spotPrice)

##### Open Interest
We need to understand what open interest is. CoinGecko wants the past 24 hours data on open interest.

#### Definitions
* Open Interest: sum of Long and Short positions open on the protocol
* Target Volume: volume of usdc traded for each market.
* Base Volume: volume of eth traded for each market.
* Position: position information for all AMM per trader
* AmmPosition: position information for certain AMM per trader

#### Pending Questiosn and queries
-- How to calculate Open Interest Total?
-- How to calculate Open Interest in past 24 hours?

**perp team response**: for these 2 properties we haven't implemented yet on subgraph, but it should be available in early Feb.

-- The following is a list of fields that we are not working on but are in the coingecko spec document:

- bid
- ask
- next_funding_rate (dont know how to predict)
- contract_price // contract_price_currency (probably not applicable)

-- We are not making an API Endpoint for orderbook as discussed with Nick.
-- Are there any other feilds that we need to work on ?
-- Are there any changes or things we should know before we start implmenting the above?