feat: remove isRegtest argument from getFeeRate, modify readme

README.md

@@ -6,8 +6,8 @@
 
 The transaction fee rate is calculated by taking the maximum value among three metrics from the Bitcoin blockchain:
 
-- Average fee rate from the last two blocks
-- Current mempool block's median fee rate
-- Estimated "fastest" fee rate
+- Average fee rate from the last two blocks `/api/v1/mining/blocks/fee-rates/24h`
+- Current mempool block's median fee rate `/api/v1/fees/mempool-blocks`
+- Recommended "fastest" fee rate by API `/api/v1/fees/recommended`
 
 Each metric is adjusted by an optional multiplier (defaults to 1.0) and the final result is rounded up to the nearest whole number. For regtest environments, a fixed fee rate of 2 is used.

src/dlc-handlers/abstract-dlc-handler.ts

@@ -1,6 +1,7 @@
 import { Transaction } from '@scure/btc-signer';
 import { P2Ret, P2TROut } from '@scure/btc-signer/payment';
 import { Network } from 'bitcoinjs-lib';
+import { regtest } from 'bitcoinjs-lib/src/networks.js';
 
 import {
   createNativeSegwitPayment,
@@ -133,11 +134,16 @@ export abstract class AbstractDLCHandler {
     }
   }
 
-  private async getFeeRate(feeRateMultiplier?: number, customFeeRate?: bigint): Promise<bigint> {
-    return (
-      customFeeRate ??
-      BigInt(await getFeeRate(this.bitcoinBlockchainFeeRecommendationAPI, feeRateMultiplier))
-    );
+  protected async getFeeRate(feeRateMultiplier?: number, customFeeRate?: bigint): Promise<bigint> {
+    if (customFeeRate) {
+      return customFeeRate;
+    }
+
+    if (this.bitcoinNetwork === regtest) {
+      return BigInt(2);
+    }
+
+    return BigInt(await getFeeRate(this.bitcoinBlockchainFeeRecommendationAPI, feeRateMultiplier));
   }
 
   async createFundingPSBT(

src/dlc-handlers/ledger-dlc-handler.ts

@@ -10,7 +10,6 @@ import {
   deriveUnhardenedPublicKey,
   ecdsaPublicKeyToSchnorr,
   getBalance,
-  getFeeRate,
   getInputByPaymentTypeArray,
   getUnspendableKeyCommittedToUUID,
 } from '../functions/bitcoin/bitcoin-functions.js';
@@ -246,9 +245,7 @@ export class LedgerDLCHandler extends AbstractDLCHandler {
         attestorGroupPublicKey
       );
 
-      const feeRate =
-        customFeeRate ??
-        BigInt(await getFeeRate(this.bitcoinBlockchainFeeRecommendationAPI, feeRateMultiplier));
+      const feeRate = await this.getFeeRate(feeRateMultiplier, customFeeRate);
 
       const addressBalance = await getBalance(fundingPayment, this.bitcoinBlockchainAPI);
 
@@ -327,9 +324,7 @@ export class LedgerDLCHandler extends AbstractDLCHandler {
         attestorGroupPublicKey
       );
 
-      const feeRate =
-        customFeeRate ??
-        BigInt(await getFeeRate(this.bitcoinBlockchainFeeRecommendationAPI, feeRateMultiplier));
+      const feeRate = await this.getFeeRate(feeRateMultiplier, customFeeRate);
 
       const withdrawTransaction = await createWithdrawTransaction(
         this.bitcoinBlockchainAPI,
@@ -388,9 +383,7 @@ export class LedgerDLCHandler extends AbstractDLCHandler {
     const { fundingPayment, taprootDerivedPublicKey, fundingDerivedPublicKey, multisigPayment } =
       await this.createPayment(vault.uuid, attestorGroupPublicKey);
 
-    const feeRate =
-      customFeeRate ??
-      BigInt(await getFeeRate(this.bitcoinBlockchainFeeRecommendationAPI, feeRateMultiplier));
+    const feeRate = await this.getFeeRate(feeRateMultiplier, customFeeRate);
 
     const depositTransaction = await createDepositTransaction(
       this.bitcoinBlockchainAPI,

src/functions/bitcoin/bitcoin-functions.ts

@@ -149,9 +149,9 @@ export function createTaprootMultisigPayment(
  *
  * @returns A promise that resolves to the last two blocks' median fee rates.
  */
-export async function getLastTwoBlocksFeeRate(
+export async function getLastTwoBlocksFeeRateAverage(
   bitcoinBlockchainAPIFeeURL: string
-): Promise<number[]> {
+): Promise<number> {
   const dayFeeRateAPI = `${bitcoinBlockchainAPIFeeURL}/api/v1/mining/blocks/fee-rates/24h`;
 
   const response = await fetch(dayFeeRateAPI);
@@ -162,7 +162,12 @@ export async function getLastTwoBlocksFeeRate(
 
   const historicalFeeRates: HistoricalFeeRate[] = await response.json();
 
-  return historicalFeeRates.slice(historicalFeeRates.length - 2).map(rate => rate.avgFee_50);
+  return (
+    historicalFeeRates
+      .slice(historicalFeeRates.length - 2)
+      .map(rate => rate.avgFee_50)
+      .reduce((a, b) => a + b) / 2
+  );
 }
 
 /**
@@ -213,30 +218,19 @@ export async function getEstimatedFeeRate(bitcoinBlockchainAPIFeeURL: string): P
  */
 export async function getFeeRate(
   bitcoinBlockchainAPIFeeURL: string,
-  feeRateMultiplier = 1,
-  isRegtest = false
+  feeRateMultiplier = 1
 ): Promise<number> {
-  if (isRegtest) return 2;
-
-  const [lastTwoBlocksFeeRate, currentBlockFeeRate, estimatedFeeRate] = await Promise.all([
-    getLastTwoBlocksFeeRate(bitcoinBlockchainAPIFeeURL),
+  const [lastTwoBlocksFeeRateAverage, currentBlockFeeRate, estimatedFeeRate] = await Promise.all([
+    getLastTwoBlocksFeeRateAverage(bitcoinBlockchainAPIFeeURL),
     getCurrentMempoolBlockFeeRate(bitcoinBlockchainAPIFeeURL),
     getEstimatedFeeRate(bitcoinBlockchainAPIFeeURL),
   ]);
 
-  const currentBlockFeeRateMultiplied = currentBlockFeeRate * feeRateMultiplier;
-
-  const lastTwoBlocksfeeRateAverageMultiplied =
-    (lastTwoBlocksFeeRate.reduce((a, b) => a + b) / lastTwoBlocksFeeRate.length) *
-    feeRateMultiplier;
-
-  const estimatedFeeRateMultiplied = estimatedFeeRate * feeRateMultiplier;
-
   return Math.ceil(
     Math.max(
-      lastTwoBlocksfeeRateAverageMultiplied,
-      currentBlockFeeRateMultiplied,
-      estimatedFeeRateMultiplied
+      lastTwoBlocksFeeRateAverage * feeRateMultiplier,
+      currentBlockFeeRate * feeRateMultiplier,
+      estimatedFeeRate * feeRateMultiplier
     )
   );
 }