feat(sdk): add gateway utility helpers for CLI and bot consumers

sdk/src/gateway/index.ts

@@ -2,5 +2,13 @@ export { OkxWalletAdapter } from './adapters/okx-wallet';
 export { ReownWalletAdapter } from './adapters/reown';
 export { ExecuteQuoteResult, GatewayApiClient as GatewaySDK } from './client';
 export * from './generated-client';
-export { GatewayQuoteParams, GetQuoteParams } from './types';
-export { formatBtc, parseBtc } from './utils';
+export { BitcoinSigner, GatewayQuoteParams, GetQuoteParams } from './types';
+export {
+    formatBtc,
+    parseBtc,
+    ScureBitcoinSigner,
+    supportedChainsMapping,
+    getChainConfig,
+    getInnerQuote,
+    type InnerQuote,
+} from './utils';

sdk/src/gateway/utils/bitcoin-signer.ts

@@ -15,6 +15,36 @@ export class ScureBitcoinSigner implements BitcoinSigner {
         this.privateKey = new Uint8Array(Buffer.from(cleanPrivateKey, 'hex'));
     }
 
+    /**
+     * Create a Bitcoin signer from a WIF-encoded private key
+     * @param wif WIF-encoded private key string
+     * @returns A new ScureBitcoinSigner instance
+     */
+    static fromWIF(wif: string): ScureBitcoinSigner {
+        const decoded = btc.WIF().decode(wif);
+        return new ScureBitcoinSigner(Buffer.from(decoded).toString('hex'));
+    }
+
+    /**
+     * Create a Bitcoin signer from a private key in any supported format (hex or WIF).
+     * Auto-detects the format.
+     * @param key Private key as hex string (with or without 0x prefix) or WIF-encoded
+     * @returns A new ScureBitcoinSigner instance
+     */
+    static fromKey(key: string): ScureBitcoinSigner {
+        const stripped = key.startsWith('0x') ? key.slice(2) : key;
+        if (/^[0-9a-fA-F]{64}$/.test(stripped)) {
+            return new ScureBitcoinSigner(stripped);
+        }
+        try {
+            return ScureBitcoinSigner.fromWIF(key);
+        } catch (e) {
+            throw new Error('Invalid private key: expected 64-char hex (with optional 0x prefix) or WIF-encoded key', {
+                cause: e,
+            });
+        }
+    }
+
     /**
      * Create a Bitcoin signer from a seed phrase (BIP39 mnemonic)
      * @param seedPhrase The BIP39 mnemonic seed phrase

sdk/src/gateway/utils/index.ts

@@ -1,2 +1,3 @@
 export * from './common';
 export * from './bitcoin-signer';
+export * from './quote';

sdk/src/gateway/utils/quote.ts

@@ -0,0 +1,31 @@
+import type { GatewayQuote } from '../generated-client/models/GatewayQuote';
+import type { GatewayOnrampQuote } from '../generated-client/models/GatewayOnrampQuote';
+import type { GatewayOfframpQuote } from '../generated-client/models/GatewayOfframpQuote';
+import type { GatewayLayerZeroQuote } from '../generated-client/models/GatewayLayerZeroQuote';
+import { instanceOfGatewayQuoteOneOf, type GatewayQuoteOneOf } from '../generated-client/models/GatewayQuoteOneOf';
+import { instanceOfGatewayQuoteOneOf1, type GatewayQuoteOneOf1 } from '../generated-client/models/GatewayQuoteOneOf1';
+import { instanceOfGatewayQuoteOneOf2, type GatewayQuoteOneOf2 } from '../generated-client/models/GatewayQuoteOneOf2';
+
+export type InnerQuote = GatewayOnrampQuote | GatewayOfframpQuote | GatewayLayerZeroQuote;
+
+/**
+ * Unwraps a GatewayQuote, returning the inner quote object directly.
+ *
+ * All three variants share common fields (inputAmount, outputAmount, fees,
+ * recipient, estimatedTimeInSecs, sender), so you can access them without
+ * caring about the variant:
+ *
+ * ```ts
+ * const inner = getInnerQuote(quote);
+ * console.log(inner.inputAmount.amount);
+ * console.log(inner.outputAmount.amount);
+ * console.log(inner.fees.amount);
+ * ```
+ */
+export function getInnerQuote(quote: GatewayQuote): InnerQuote {
+    const q = quote as object;
+    if (instanceOfGatewayQuoteOneOf(q)) return (q as GatewayQuoteOneOf).onramp;
+    if (instanceOfGatewayQuoteOneOf1(q)) return (q as GatewayQuoteOneOf1).offramp;
+    if (instanceOfGatewayQuoteOneOf2(q)) return (q as GatewayQuoteOneOf2).layerZero;
+    throw new Error('Unknown quote variant');
+}

sdk/src/mempool.ts

@@ -252,6 +252,20 @@ export class MempoolClient {
         return Infinity;
     }
 
+    /**
+     * Get pending (unconfirmed) transactions for a Bitcoin address from the mempool.
+     *
+     * @param {string} address - The Bitcoin address to check.
+     * @returns {Promise<MempoolTxInfo[]>} Array of unconfirmed transactions.
+     *
+     * @example
+     * const mempoolClient = new MempoolClient();
+     * const pendingTxs = await mempoolClient.getAddressMempoolTxs('bc1q...');
+     */
+    async getAddressMempoolTxs(address: string): Promise<MempoolTxInfo[]> {
+        return this.getJson<MempoolTxInfo[]>(`${this.basePath}/address/${address}/txs/mempool`);
+    }
+
     /**
      * @ignore
      */

sdk/src/wallet/index.ts

@@ -1,3 +1,7 @@
 export * from './utxo';
 
-export { validate as isValidBtcAddress } from 'bitcoin-address-validation';
+export {
+    validate as isValidBtcAddress,
+    getAddressInfo as getBtcAddressInfo,
+    AddressType as BtcAddressType,
+} from 'bitcoin-address-validation';