Quickstart

This walks one swap end to end over REST. The server builds unsigned transactions; you sign every transaction yourself. The server never signs anything that moves your funds. All amounts are base-unit integer strings (satoshis, wei, token base units). A price (askAmount, quoteAmount) has at most 8 decimals of its asset, fewer when the asset has fewer; the API refuses more with “a price has at most N decimals” (N is 8, or the asset’s own count when it has fewer), so round a computed price down.

export HL=https://api.hashlock.markets

1. Get an API key

Pick one path.

Web page
Wallet signature (agents)

No browser needed. Get a nonce, sign a message with the wallet, post it.

import { privateKeyToAccount } from 'viem/accounts';

const HL = 'https://api.hashlock.markets';
const account = privateKeyToAccount(process.env.EVM_KEY as `0x${string}`);

const { nonce } = await (await fetch(`${HL}/v1/keys/nonce`)).json();
const message = [
  'Hashlock Markets — create an API key.',
  '',
  `Address: ${account.address}`,
  'Key name: my-bot',
  'Scopes: read, taker, maker',
  `Nonce: ${nonce}`,
].join('\n');

const signature = await account.signMessage({ message }); // personal_sign / EIP-191
const res = await fetch(`${HL}/v1/keys`, {
  method: 'POST',
  headers: { 'content-type': 'application/json' },
  body: JSON.stringify({ rail: 'evm', address: account.address, message, signature }),
});
const { key, expiresAt } = await res.json(); // key = "hk_live_…", shown once

See API keys for the message rules, other chains and key limits.

Check the key:

curl -s $HL/v1/me -H "Authorization: Bearer $HK"

The response lists your scopes and, per chain, your login wallet and the wallets you have proven.

2. Prove the wallets you will give from

To create an order that gives an asset, your account needs a proven wallet on that asset’s chain. A key starts with only the address its account signed in with.

const { nonce } = await (await fetch(`${HL}/v1/wallets/nonce`, { headers: { Authorization: `Bearer ${HK}` } })).json();
const message = `Hashlock Markets — link this wallet.\n\nAddress: ${account.address}\nNonce: ${nonce}`;
const signature = await account.signMessage({ message });
await fetch(`${HL}/v1/wallets/evm`, {
  method: 'POST',
  headers: { Authorization: `Bearer ${HK}`, 'content-type': 'application/json' },
  body: JSON.stringify({ address: account.address, message, signature }),
});

TRON, Solana and Bitcoin use POST /v1/wallets/tron|solana|bitcoin. To be paid on, or fund TRON from, a wallet on another chain, add your login wallet’s authorisation — see Authorising a wallet.

3. Create an RFQ (taker) or quote one (maker)

List assets to get their ids:

curl -s $HL/v1/assets -H "Authorization: Bearer $HK"

Taker — create an RFQ (needs the taker scope):

curl -s -X POST $HL/v1/rfqs \
  -H "Authorization: Bearer $HK" -H "content-type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
    "direction": "sell_base",
    "baseAssetId": "<asset uuid>",
    "baseAmount": "50000000",
    "quoteAssetId": "<asset uuid>",
    "ttlSeconds": 900,
    "visibility": "public"
  }'

sell_base means you give the base asset. buy_base means you receive it. A private order needs an askAmount and is reachable by link only; it can name a targetAddress. Maker — quote an RFQ (needs the maker scope). This opens a negotiation thread:

curl -s -X POST $HL/v1/rfqs/$RFQ_ID/quotes \
  -H "Authorization: Bearer $HK" -H "content-type: application/json" \
  -d '{ "quoteAmount": "1500000000" }'

Makers can also stream RFQs and quote over the maker feed. Taker — each quote opens a thread. List them to get the THREAD_ID:

curl -s $HL/v1/rfqs/$RFQ_ID/threads -H "Authorization: Bearer $HK"

Or register a quote.created webhook and be told.

4. Negotiate and accept

Read the thread, counter if you want, then accept at the price you read.

curl -s $HL/v1/threads/$THREAD_ID -H "Authorization: Bearer $HK"

# counter
curl -s -X POST $HL/v1/threads/$THREAD_ID/propose -H "Authorization: Bearer $HK" \
  -H "content-type: application/json" -d '{ "quoteAmount": "1490000000" }'

# accept the other side's pending price (must equal pendingAmount)
curl -s -X POST $HL/v1/threads/$THREAD_ID/accept-proposal -H "Authorization: Bearer $HK" \
  -H "content-type: application/json" -d '{ "quoteAmount": "1490000000" }'

Accepting the terms commits and cannot be undone. The initiator — the party who funds the long leg, see Roles — must also send hashlock = sha256(secret):

import { randomBytes, createHash } from 'node:crypto';

const secret = randomBytes(32);                                  // keep this private and safe
const hashlock = createHash('sha256').update(secret).digest('hex'); // 64 hex chars, no 0x

await fetch(`${HL}/v1/threads/${threadId}/accept`, {
  method: 'POST',
  headers: { Authorization: `Bearer ${HK}`, 'content-type': 'application/json' },
  body: JSON.stringify({ quoteAmount: currentQuoteAmount, hashlock }),
});

When both sides have accepted, the response includes the new swap.

5. Set settlement addresses

For each chain of the swap, set your address. On the chain you receive on it is your payout address; on the chain you fund it is your refund address. For Bitcoin, send the compressed public key (hex); the server derives the P2WSH escrow once both sides are set.

curl -s -X POST $HL/v1/swaps/$SWAP_ID/address -H "Authorization: Bearer $HK" \
  -H "content-type: application/json" \
  -d '{ "chain": "ethereum", "address": "0xYourAddress" }'

Pass "leg": "a" or "b" only when both legs are on the same chain. Over the API, an address that receives money must be your login wallet, one it authorised, or one proven from a signed-in web session — see API keys.

6. Fund your leg

The maker funds leg a; the taker funds leg b. The initiator funds first: the counterparty’s fund builder refuses until the initiator’s leg is funded.

curl -s -X POST $HL/v1/swaps/$SWAP_ID/legs/$MY_FUND_LEG/fund -H "Authorization: Bearer $HK"

The response is chain-specific signing material. Sign it locally and broadcast. For an EVM leg:

import { createPublicClient, createWalletClient, http } from 'viem';
import { mainnet } from 'viem/chains'; // use the chain your swap's leg is on

const build = await (await fetch(`${HL}/v1/swaps/${swapId}/legs/${myFundLeg}/fund`, {
  method: 'POST', headers: { Authorization: `Bearer ${HK}` },
})).json();
// { sign: 'evm-tx', chainId, from, txs: [{ to, data, value /* hex wei */ }, ...] }
// Sign every tx from `build.from` — the factory refuses any other sender.
const wallet = createWalletClient({ account, chain: mainnet, transport: http() });
const reader = createPublicClient({ chain: mainnet, transport: http() });

for (const tx of build.txs) {
  const request = await wallet.prepareTransactionRequest({
    account, to: tx.to, data: tx.data, value: BigInt(tx.value),
  });
  const signed = await wallet.signTransaction(request);
  const { txid } = await (await fetch(`${HL}/v1/tx/broadcast`, {
    method: 'POST',
    headers: { Authorization: `Bearer ${HK}`, 'content-type': 'application/json' },
    body: JSON.stringify({ chain: 'evm', signed }),
  })).json();
  await reader.waitForTransactionReceipt({ hash: txid }); // an ERC-20 approve must land before createSwap
}

Check each transaction from the build response before signing. Per-chain shapes (Bitcoin, TRON, Solana) are in Settle a leg.

7. Claim

Once both legs are funded, the initiator claims the leg they receive on (the maker receives on leg b, the taker on leg a). That reveals the secret on chain.

curl -s -X POST $HL/v1/swaps/$SWAP_ID/legs/$MY_RECEIVE_LEG/claim -H "Authorization: Bearer $HK" \
  -H "content-type: application/json" -d '{ "secret": "<32-byte hex preimage>" }'

Sign and broadcast as in step 6. The counterparty then claims the other leg with the now-public secret. If nobody claims, each funder takes their leg back after its timelock with POST /v1/swaps/{id}/legs/{leg}/refund. Track state with GET /v1/swaps/{id} or webhooks.

Get started

Concepts

Guides

AI agents

1. Get an API key

2. Prove the wallets you will give from

3. Create an RFQ (taker) or quote one (maker)

4. Negotiate and accept

5. Set settlement addresses

6. Fund your leg

7. Claim