The Astar Gas Station

note

Integrate with the Astar Networks Gas Station for optimal priority fee.

Documentation of the calculations

GasPriceOracle

• Each EVM RPC is queried using the GasPriceOracle module

    const oracle = new GasPriceOracle({
      defaultRpc: 'https://evm.shibuya.astar.network',
      blocksCount: 200,
      chainId: 81,
    });
    
    /*
    {
      estimate: {
        baseFee: 779.371350051,
        maxFeePerGas: 782.371350051,
        maxPriorityFeePerGas: 3
      },
      gasPrices: {
        instant: 1013.182755066,
        fast: 935.245620061,
        standard: 857.308485056,
        low: 779.371350051
      }
    }
    */

• The GasPriceOracle Github repo does not mention how it does it’s calculations but from the results I could infer and confirm these results:
  1. Low Gas Price: is the base fee.
  2. Standard Gas Price: 110% of the base fee.
  3. Fast Gas Price: 120% of the base fee.
  4. Instant Gas Price: 130% of the base fee.

Estimates

• 8 months ago (October 30, 2022), a change was implemented to gather the gasPrices from the last 20 blocks and use percentiles of the results.

for (let i = latest.number; i > latest.number - 20; i--) {
      block = await web3[network].eth.getBlock(i);
      for (let j = 0; j < block.transactions.length; j++) {
        txn = await web3[network].eth.getTransaction(block.transactions[j]);
        gasPrices.push(Number(txn.gasPrice));
      }
    }

const percentiles = percentile([35, 60, 90, 99], gasPrices);

GasPriceOracle

• As of November 1st, 2023, the GasPriceOracle, is bein used as fall back values if an error occurred and the percentiles were undefined.

Substrate Tip Calculation

• The substrate tip is exactly the EVM price calculations multiplied:
  $Tip Value=Gas Price×1000$

Using the gas station

• Shibuya API: GET https://gas.astar.network/api/gasnow?network=shibuya&type=tip
• Shiden API: GET https://gas.astar.network/api/gasnow?network=shiden&type=tip
• Astar API: GET https://gas.astar.network/api/gasnow?network=astar&type=tip

Example output

{
   "code":200,
   "data":{
      "average":"857308485056",
      "fast":"935245620061",
      "slow":"779371350051",
      "fastest":"1013182755066",
      "eip1559":{
         "priorityFeePerGas":{
            "average":"857308485056",
            "fast":"935245620061",
            "slow":"779371350051",
            "fastest":"1013182755066"
         },
         "maxPriorityFeePerGas":"3000000000",
         "baseFeePerGas":"779000000000",
         "maxFeePerGas":"782000000000"
      },
      "tip":{
         "average":"857308485056000",
         "fast":"935245620061000",
         "slow":"779371350051000",
         "fastest":"1013182755066000"
      },
      "timestamp":1699544357434
   }
}

Related Documents

Include any links to relevant external documents.

• Repo: https://github.com/AstarNetwork/gas-station
• website: https://gas.astar.network/