Hashlock Markets SDK

Official TypeScript and Python SDKs for the Hashlock Markets developer API — non-custodial cross-chain atomic swaps (BTC ↔ EVM / TRON / Solana) over sealed RFQ + HTLC.

⚠️ Sandbox / testnet preview (0.x). The SDK defaults to the public sandbox (api-dev.hashlock.markets) and targets testnets only — pre-mainnet, pre-external-audit. The API surface may still change before the stable 1.0 release, which will accompany mainnet. Don't use with mainnet funds.

• Non-custodial. Settlement endpoints return unsigned transactions. You sign with your own key or HSM; the server never holds your keys.
• Native, no bridge. Real BTC ↔ real EVM/TRON/Solana assets, settled directly via HTLC — no wrapped tokens, no bridge, no custody of principal.
• One API, two roles. Takers post RFQs; makers quote them; both settle their legs with the same builders. Plus webhooks and a maker WebSocket feed.

Package	Language	Install
typescript/	TypeScript / JS (Node 18+, browsers, edge)	npm i @hashlock-tech/sdk
python/	Python 3.9+	pip install hashlock-sdk
examples/	Quickstarts + Fireblocks/Copper signing reference	—

Upgrading to 0.5.0

Solana is a settlement rail here now, and two older shapes were wrong:

• BtcWitnessBuild is gone. Bitcoin claims and refunds answer with BtcSighashBuild — a PSBT and one sighash per swept input — which is what the API has returned since 13 August. Sign each sighash and pass { psbtBase64, signaturesHex, preimageHex? } back to broadcast('bitcoin', …).
• TronBuild.family is 'tvm', not 'tron'. A family === 'tron' branch never ran. The chain name in broadcast('tron', …) is unchanged — that route has its own vocabulary.

New: SolanaBuild (sign: 'solana-tx'), broadcast('solana', signedBase64), and feePayTo / feeAmountSats on a Bitcoin funding build — pay both or the leg does not count as funded.

Quick start (TypeScript)

import { HashlockClient, newSecret } from '@hashlock-tech/sdk';

const client = new HashlockClient({ apiKey: process.env.HASHLOCK_API_KEY! }); // hk_test_… / hk_live_…

const assets = await client.assets();
const btc = assets.find((a) => a.symbol === 'BTC')!;
const usdt = assets.find((a) => a.chain === 'ethereum' && a.symbol === 'USDT')!;

// Taker: sell BTC for USDT (funds the long leg → is the initiator).
const rfq = await client.createRfq({
  direction: 'sell_base',
  baseAssetId: btc.id,
  baseAmount: '10000', // sats
  quoteAssetId: usdt.id,
  ttlSeconds: 3600,
});

// …a maker quotes it, both accept (the initiator passes hashlock = sha256(secret)),
// then each side funds/claims its leg with the unsigned-tx builders.
const { hashlock } = await newSecret();

See examples/quickstart.ts for the full lifecycle, and examples/fireblocks for signing the unsigned transactions with a custody provider.

How a swap works

1. RFQ → quote → accept. A taker posts an RFQ; a maker quotes it (opening a negotiation thread); both accept the terms. The initiator (whoever funds the long-timelock leg) generates a secret locally and submits only hashlock = sha256(secret). When both accept, the swap is created.
2. Addresses. Each side sets its receive (payout) / refund address per leg (setSwapAddress). Bitcoin uses the compressed pubkey — the server derives the P2WSH.
3. Fund. The initiator funds the long leg; the counterparty funds the short leg. Each buildFund call returns an unsigned transaction — you sign and broadcast. Funding is EVM txs, a Bitcoin payment, a Solana transaction or TRON txs; claiming and refunding hand Bitcoin back as PSBT sighashes.
4. Claim. The initiator claims the short leg with the secret — revealing it on-chain. The counterparty reads the secret and claims the long leg. Atomic: both legs settle, or both refund after their timelocks.

The same sha256(secret) hashlock binds every leg; asymmetric timelocks (long leg ≫ short leg) remove the free-option/griefing risk.

Core surface

• Auth: API key (Authorization: Bearer hk_… or X-Api-Key), scopes read | taker | maker.
• Market: assets(), listRfqs() / rfqs() (cursor-paginated), getRfq(), createRfq(), quoteRfq().
• Negotiation: getThread(), proposeTerms(), acceptProposal(), acceptTerms().
• Swaps: listSwaps() / swaps(), getSwap(), setSwapAddress().
• Settlement (unsigned): buildFund(), buildClaim(), buildRefund(), broadcast().
• Webhooks: createWebhook(), listWebhooks(), deleteWebhook(), pingWebhook() + verifyWebhook().
• Maker feed: MakerFeed — stream quotable RFQs and submit quotes over a WebSocket.

Interactive API reference: https://api-dev.hashlock.markets/v1/docs (OpenAPI at /v1/openapi.json).

License

MIT — see LICENSE.