support rbf

2 files changed, 37 insertions, 23 deletions

diff --git a/lib/buildliquidtx.js b/lib/buildliquidtx.js
index d84bdc0b..4dd3a16c 100644
--- a/lib/buildliquidtx.js
+++ b/lib/buildliquidtx.js
@@ -2,11 +2,20 @@ const axios = require("axios");
 const liquid = require("liquidjs-lib");
 const coinselect = require("coinselect");
 const split = require("coinselect/split");
-const api = prod ? "https://blockstream.info/liquid/api" : "http://localhost:3002";
+const api = prod
+  ? "https://blockstream.info/liquid/api"
+  : "http://localhost:3002";
 const SATS = 100000000;
 const network = prod ? liquid.networks["liquid"] : liquid.networks["regtest"];
 
-module.exports = async ({ address, asset, amount, feeRate, user }) => {
+module.exports = async ({
+  address,
+  asset,
+  amount,
+  feeRate,
+  replaceable,
+  user
+}) => {
   const { btcasset: btc } = config.liquid;
 
   if (!feeRate) {
@@ -17,13 +26,12 @@ module.exports = async ({ address, asset, amount, feeRate, user }) => {
   feeRate = Math.round(feeRate / 100);
   if (asset !== btc) feeRate = 0;
 
-
   const payments = await db.Payment.findAll({
     where: {
       received: true,
       account_id: user.account_id,
-      network: 'liquid',
-    },
+      network: "liquid"
+    }
   });
 
   let utxos = [];
@@ -36,18 +44,21 @@ module.exports = async ({ address, asset, amount, feeRate, user }) => {
     }
   }
 
-  let feeInput = utxos.find((utxo) => utxo.asset === btc && utxo.value > 1000);
-  if (!feeInput) throw new Error("Insufficient balance, couldn't find an input to cover the fee");
+  let feeInput = utxos.find(utxo => utxo.asset === btc && utxo.value > 1000);
+  if (!feeInput)
+    throw new Error(
+      "Insufficient balance, couldn't find an input to cover the fee"
+    );
 
-  utxos = utxos.filter((utxo) => utxo.asset === asset);
+  utxos = utxos.filter(utxo => utxo.asset === asset);
 
   let feeChange = feeInput.value - 1000;
 
   let targets = [
     {
       address,
-      value: amount,
-    },
+      value: amount
+    }
   ];
 
   let { inputs, outputs, fee } = coinselect(utxos, targets, feeRate);
@@ -56,7 +67,7 @@ module.exports = async ({ address, asset, amount, feeRate, user }) => {
       "utxos",
       amount,
       feeRate,
-      utxos.map((u) => u.value),
+      utxos.map(u => u.value),
       inputs,
       outputs,
       fee
@@ -82,7 +93,7 @@ module.exports = async ({ address, asset, amount, feeRate, user }) => {
     psbt = psbt.addOutput({
       address,
       asset,
-      value,
+      value
     });
   });
 
@@ -91,7 +102,7 @@ module.exports = async ({ address, asset, amount, feeRate, user }) => {
     psbt = psbt.addInput({
       hash: txid,
       index: vout,
-      nonWitnessUtxo: Buffer.from((await lq.getTransaction(txid)).hex, "hex"),
+      nonWitnessUtxo: Buffer.from((await lq.getTransaction(txid)).hex, "hex")
     });
   }
 
@@ -100,25 +111,26 @@ module.exports = async ({ address, asset, amount, feeRate, user }) => {
       hash: feeInput.txid,
       index: feeInput.vout,
       nonWitnessUtxo: Buffer.from(
-        (await lq.getTransaction(feeInput.txid).hex),
+        await lq.getTransaction(feeInput.txid).hex,
         "hex"
-      ),
+      )
     });
 
     psbt.addOutput({
       changeAddress,
       asset: btc,
-      value: feeChange,
+      value: feeChange
     });
   }
 
+  psbt.addOutput({
+    asset: btc,
+    script: Buffer.alloc(0),
+    value: fee,
+    nonce: Buffer.alloc(1, 0)
+  });
 
-    psbt.addOutput({
-      asset: btc,
-      script: Buffer.alloc(0),
-      value: fee,
-      nonce: Buffer.alloc(1, 0),
-    });
+  if (replaceable) psbt.setInputSequence(0, 0xffffffff - 2);
 
   feeRate = Math.round(feeRate * 1000);
   psbt = psbt.toBase64();
diff --git a/lib/buildtx.js b/lib/buildtx.js
index ef24ea19..0f63f641 100644
--- a/lib/buildtx.js
+++ b/lib/buildtx.js
@@ -8,7 +8,7 @@ const network = prod
   ? bitcoin.networks["bitcoin"]
   : bitcoin.networks["regtest"];
 
-module.exports = async ({ address, amount, feeRate, user }) => {
+module.exports = async ({ address, amount, feeRate, replaceable, user }) => {
   if (!feeRate) feeRate = (await bc.estimateSmartFee(6)).feerate * SATS;
   feeRate = Math.round(feeRate / 1000);
 
@@ -69,6 +69,8 @@ module.exports = async ({ address, amount, feeRate, user }) => {
     });
   }
 
+  if (replaceable) psbt.setInputSequence(0, 0xffffffff - 2);
+
   feeRate = Math.round(feeRate * 1000);
   psbt = psbt.toBase64();