This tool fetches the HBAR - USD exchange rate from all the exchanges that allow HBAR trading and calculates their weighted median [Weight is the volume of HABR - USD trading occurred on that exchange in the last 24 hours]. Once the Median is calculated we perform a smoothing operation to keep the rate in bound from the rate at previous midnight. This Smoothed Median is then pushed to the Hedera Network[can push to multiple Hedera Networks in a single run] as the rate that is to be used for the next hour as the base for fee calculations for all transactions.
Currently 3 ERT instances run. Instance 1 pushes rates to Mainnet Instance 2 pushes rates to Stable Testnet Instance 3 pushes rates to Preview Testnet, Staging-lg, Staging-sm, Integration and Performance Testing
We periodically [hourly] run this tool using AWS lambda.
This tool also provides 2 APIs.
- ExchangeRateAPI - This gives the latest exchange rate that this tool has pushed to the Hedera Network.
- ExchnageRateHistoryAPI - This gives the data from the previous runs which includes
- All the data from exchanges that it fetched.
- The median it calculated.
- If that median is smoothed.
- Previous Midnight Rate.
Exchanges that we are currently pulling latest HBAR-USD exchange rate from:
- Liquid
- Bittrex
- OKCoin
- Binance