🚧 (smpl): wip psbt creation

apps/sample/package.json

@@ -27,8 +27,13 @@
     "@ledgerhq/device-transport-kit-web-hid": "workspace:*",
     "@ledgerhq/react-ui": "^0.17.0",
     "@playwright/test": "^1.49.0",
+    "@scure/base": "^1.2.1",
+    "@scure/bip32": "^1.6.1",
     "@sentry/nextjs": "^8.42.0",
+    "bitcoinjs-lib": "^6.1.6",
+    "bs58check": "^4.0.0",
     "ethers": "6.13.4",
+    "micro-btc-signer": "^0.4.2",
     "next": "14.2.15",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",

apps/sample/src/components/SignerBtcView/index.tsx

@@ -16,10 +16,11 @@ import {
 
 import { DeviceActionsList } from "@/components/DeviceActionsView/DeviceActionsList";
 import { type DeviceActionProps } from "@/components/DeviceActionsView/DeviceActionTester";
+import psbtBase64 from "@/components/SignerBtcView/psbt";
 import { useDmk } from "@/providers/DeviceManagementKitProvider";
 
 // Native segwit
-const DEFAULT_DERIVATION_PATH = "84'/0'/0'";
+const DEFAULT_DERIVATION_PATH = "86'/0'/0'";
 
 export const SignerBtcView: React.FC<{ sessionId: string }> = ({
   sessionId,
@@ -47,7 +48,7 @@ export const SignerBtcView: React.FC<{ sessionId: string }> = ({
           });
         },
         initialValues: {
-          derivationPath: "84'/0'/0'",
+          derivationPath: DEFAULT_DERIVATION_PATH,
           checkOnDevice: false,
         },
         deviceModelId,
@@ -103,7 +104,7 @@ export const SignerBtcView: React.FC<{ sessionId: string }> = ({
         },
         initialValues: {
           derivationPath: DEFAULT_DERIVATION_PATH,
-          psbt: "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",
+          psbt: psbtBase64,
         },
         deviceModelId,
       } satisfies DeviceActionProps<

apps/sample/src/components/SignerBtcView/psbt.ts

@@ -0,0 +1,117 @@
+import { base64, hex } from "@scure/base";
+import { HDKey } from "@scure/bip32";
+import * as bitcoin from "bitcoinjs-lib";
+import * as btc from "micro-btc-signer";
+
+const ACCT_XPUB =
+  "xpub6ChVjsbs6gVVb7urXG5fzPegohAKvhDwdnC1cr9PLUJcYWWVv1VUy4vdUrstiUsL9CNyXicxmogj6zsSExDsQKKZuMpApZMr1f3YMZB72VD";
+const MASTER_FINGERPRINT_HEX = "ee4cc60f";
+
+function createTaprootPSBT(utxos, recipientOutput, changeOutput) {
+  try {
+    const accountKey = HDKey.fromExtendedKey(ACCT_XPUB);
+    console.log("ACC KEY", accountKey.publicKey);
+
+    const childKeyRecipient = accountKey.derive(recipientOutput.path);
+    const compressedPubKeyRecipient = childKeyRecipient.publicKey;
+    const xonlyPubKeyRecipient = compressedPubKeyRecipient.slice(1);
+
+    const childKeyChange = accountKey.derive(changeOutput.path);
+    const compressedPubKeyChange = childKeyChange.publicKey;
+    const xonlyPubKeyChange = compressedPubKeyChange.slice(1);
+
+    console.log("Recipient x-only:", hex.encode(xonlyPubKeyRecipient));
+    console.log("Change x-only:   ", hex.encode(xonlyPubKeyChange));
+
+    const tx = new btc.Transaction();
+
+    const p2trRecipient = btc.p2tr(
+      xonlyPubKeyRecipient,
+      undefined,
+      bitcoin.networks.bitcoin,
+    );
+    const p2trChange = btc.p2tr(
+      xonlyPubKeyRecipient,
+      undefined,
+      bitcoin.networks.bitcoin,
+    );
+
+    for (const utxo of utxos) {
+      tx.addInput({
+        txid: utxo.tx_hash,
+        index: utxo.tx_output_n,
+        redeemScript: p2trRecipient.redeemScript,
+        witnessUtxo: {
+          script: p2trRecipient.script,
+          amount: BigInt(utxo.value),
+        },
+        tapInternalKey: accountKey.publicKey!.slice(1),
+        bip32_derivation: [
+          [
+            hex.encode(compressedPubKeyRecipient),
+            {
+              master_fingerprint: hex.decode(MASTER_FINGERPRINT_HEX),
+              path: "m/86'/0'/0'/" + recipientOutput.path.slice(2),
+              pubkey: compressedPubKeyRecipient,
+            },
+          ],
+        ],
+      });
+    }
+
+    tx.addOutput({
+      script: p2trRecipient.script,
+      amount: BigInt(recipientOutput.amount),
+      tapInternalKey: xonlyPubKeyRecipient,
+    });
+
+    tx.addOutput({
+      script: p2trChange.script,
+      amount: BigInt(changeOutput.amount),
+      tapInternalKey: xonlyPubKeyChange,
+      bip32_derivation: [
+        [
+          hex.encode(compressedPubKeyChange),
+          {
+            master_fingerprint: hex.decode(MASTER_FINGERPRINT_HEX),
+            path: "86'/0'/0'/" + changeOutput.path.slice(2),
+            pubkey: compressedPubKeyChange,
+          },
+        ],
+      ],
+    });
+
+    const psbt = tx.toPSBT(0);
+    const psbtBase64 = base64.encode(psbt);
+    console.log("PSBT (Base64):", psbtBase64);
+
+    console.log(
+      JSON.stringify(bitcoin.Psbt.fromBase64(psbtBase64).data, null, 2),
+    );
+
+    return psbtBase64;
+  } catch (err) {
+    console.error("Error creating Taproot PSBT:", err);
+    throw err;
+  }
+}
+
+const utxos = [
+  {
+    tx_hash: "db87829c15a5e3100c41563bad05d65c129f637f91705628afb16a2b33c50d27",
+    tx_output_n: 1,
+    value: 300000,
+  },
+];
+
+const recipientOutput = {
+  path: "m/0/7",
+  amount: 200000,
+};
+
+const changeOutput = {
+  path: "m/1/0",
+  amount: 100000,
+};
+
+export default createTaprootPSBT(utxos, recipientOutput, changeOutput);