[v2] add babylon craft stake + sign (#166)

* add `@fireblocks/psbt-sdk` + `bitcoinjs-lib`

* add babylon functions

* nit

* fix

package.json

@@ -36,12 +36,14 @@
     "@cosmjs/proto-signing": "^0.30.1",
     "@cosmjs/stargate": "^0.30.1",
     "@emurgo/cardano-serialization-lib-nodejs": "^11.5.0",
+    "@fireblocks/psbt-sdk": "^0.0.5",
     "@solana/web3.js": "^1.93.0",
     "@substrate/txwrapper-polkadot": "^7.5.1",
     "@taquito/local-forging": "^17.5.2",
     "@taquito/rpc": "^16.2.0",
     "@types/bn.js": "^5.1.5",
     "axios": "^1.7.2",
+    "bitcoinjs-lib": "^6.1.6",
     "bn.js": "^5.2.1",
     "ethers": "^5.7.2",
     "fireblocks-sdk": "^4.2.0",

src/kiln.ts

@@ -21,6 +21,7 @@ import { ZetaService } from "./services/zeta";
 import { KILN_VALIDATORS as v } from "./validators";
 import { KavaService } from "./services/kava";
 import { PolService } from "./services/pol";
+import { BabylonService } from "./services/babylon";
 
 type Config = {
   apiToken: string;
@@ -52,6 +53,7 @@ export class Kiln {
   zeta: ZetaService;
   kava: KavaService;
   pol: PolService;
+  babylon: BabylonService;
 
   constructor({ testnet, apiToken, baseUrl }: Config) {
     api.defaults.headers.common.Authorization = `Bearer ${apiToken}`;
@@ -79,5 +81,6 @@ export class Kiln {
     this.zeta = new ZetaService({ testnet });
     this.kava = new KavaService({ testnet });
     this.pol = new PolService({ testnet });
+    this.babylon = new BabylonService({ testnet });
   }
 }

src/services/babylon.ts

@@ -0,0 +1,67 @@
+import { Service } from "./service";
+import type { BitcoinTx, BitcoinSignedTx, BitcoinTxHash } from "../types/bitcoin";
+import api from "../api";
+import { Psbt } from "bitcoinjs-lib";
+import type { ServiceProps } from "../types/service";
+import type { Integration } from "../types/integrations";
+import { FireblocksSigner as FireblocksPsbtSigner } from "@fireblocks/psbt-sdk";
+
+export class BabylonService extends Service {
+  constructor({ testnet }: ServiceProps) {
+    super({ testnet });
+  }
+
+  /**
+   * Craft a babylon stake transaction
+   */
+  async craftStakeTx(accountId: string, publicKey: string, amountSatoshi: number, timeLock: number, feeRate: number): Promise<BitcoinTx> {
+    const { data } = await api.post<BitcoinTx>('/v1/babylon/transaction/stake', {
+      account_id: accountId,
+      public_key: publicKey,
+      amount_satoshi: amountSatoshi,
+      time_lock: timeLock,
+      fee_rate: feeRate,
+    });
+    return data;
+  }
+
+  /**
+   * Sign transaction with given integration
+   * @param integration custody solution to sign with
+   * @param tx raw babylon transaction
+   * @param note note to identify the transaction in your custody solution
+   */
+  async sign(integration: Integration, tx: BitcoinTx, note?: string): Promise<BitcoinSignedTx> {
+    const fbSigner = await FireblocksPsbtSigner.create({
+      fireblocks: {
+        basePath: "https://api.fireblocks.io/v1",
+        apiKey: integration.fireblocksApiKey,
+        secretKey: integration.fireblocksSecretKey,
+      },
+      assetId: this.testnet ? "BTC_TEST" : "BTC",
+      vaultId: integration.vaultId.toString(),
+      addressIndex: 0,
+      note: note ?? "BTC tx from @kilnfi/sdk",
+    });
+
+    const psbt = Psbt.fromHex(tx.data.unsigned_tx_serialized);
+
+    await psbt.signAllInputsAsync(fbSigner);
+
+    psbt.finalizeAllInputs();
+    const signedTransaction = psbt.extractTransaction().toHex();
+
+    return { data: { signed_tx_serialized: signedTransaction } };
+  }
+
+  /**
+   * Broadcast transaction to the network
+   * @param signedTx the transaction to broadcast
+   */
+  async broadcast(signedTx: BitcoinSignedTx): Promise<BitcoinTxHash> {
+    const { data } = await api.post<BitcoinTxHash>('/v1/babylon/transaction/broadcast', {
+      tx_serialized: signedTx.data.signed_tx_serialized,
+    });
+    return data;
+  }
+}

src/types/bitcoin.ts

@@ -0,0 +1,17 @@
+export type BitcoinTx = {
+  data: {
+    unsigned_tx_serialized: string;
+  };
+};
+
+export type BitcoinSignedTx = {
+  data: {
+    signed_tx_serialized: string;
+  };
+};
+
+export type BitcoinTxHash = {
+  data: {
+    tx_id: string;
+  };
+};