fee estimation

1 files changed, 35 insertions, 0 deletions

diff --git a/estimateLiquidFee.js b/estimateLiquidFee.js
new file mode 100644
index 00000000..fc1655b6
--- /dev/null
+++ b/estimateLiquidFee.js
@@ -0,0 +1,35 @@
+const config = require("./config");
+const BitcoinCore = require("bitcoin-core");
+
+const l = require("pino")();
+const SATS = 100000000;
+
+const bc = new BitcoinCore(config.liquid);
+
+module.exports = (app, db, emit) => async (req, res) => {
+  let { user } = req;
+  let { address, amount, confTarget, feeRate, mode } = req.body;
+  let tx, fee;
+
+  try {
+    amount = parseInt(amount);
+
+    tx = await bc.createRawTransaction([], {
+      [address]: (amount / SATS).toFixed(8)
+    });
+
+    let params = {
+      subtractFeeFromOutputs: amount === user.balance ? [0] : []
+    } 
+
+    if (feeRate) params["feeRate"] = (parseInt(feeRate) / SATS * 1000).toFixed(8);
+    if (confTarget) params["conf_target"] = parseInt(confTarget);
+    if (mode) params["estimate_mode"] = mode;
+
+    tx = await bc.fundRawTransaction(tx, params);
+    res.send({ tx });
+  } catch (e) {
+    l.error(e);
+    return res.status(500).send(e.message);
+  }
+};