Quickstart Integration Guide

This guide explains how to integrate with the Haiku Intents API. It also includes a complete client-side example for executing transactions, handling approvals, and signing Permit2 data.

This example demonstrates how to complete the following actions:

1. Request an intent quote with /quoteIntent

2. Handle token approvals for the Permit2 contract.

3. Sign Permit2 sub-allowance data.

4. [Optional] Sign the post-bridge operation if required

5. Construct the final transaction using /solveIntent

6. Execute the transaction using a Web3 wallet.

import { ethers, JsonRpcProvider } from "ethers";

const userAddress = "0x<YOUR_ADDRESS>";
const userPrivateKey ="<YOUR_PRIVATE_KEY>";

const RPC_MAIN = "https://arbitrum.llamarpc.com";

async function main() {
  const provider = new JsonRpcProvider(RPC_MAIN);
  const wallet = new ethers.Wallet(userPrivateKey, provider);
  const haikuApiBaseUrl = "https://api.haiku.trade/v1";

  const headers = {
    "Content-Type": "application/json",
    "api-key": "<your_haiku_api_key>",
  };

  // Fetch a quote for your Intent
  const quoteIntentPayload = {
    intent: {
      receiver: userAddress,
      slippage: 0.003,                                            // 0.3% max slippage
      input_positions: {
        "arb:0xaf88d065e77c8cc2239327c5edb3a432268e5831": "1",   // $1 USDC(Arb)
        "arb:0xfd086bc7cd5c481dcc9c85ebe478a1c0b69fcbb9": "0.3", // $0.30 USDT(Arb)
      },
      target_weights: { 
        "arb:0x82af49447d8a07e3bd95bd0d56f35241523fbab1": 1      // 100% WETH(Arb)
      },
    },
  };
  console.log("Fetching a quote for the Intent...");
  const quoteRes = await fetch(`${haikuApiBaseUrl}/quoteIntent`, {
    method: "POST",
    headers: headers,
    body: JSON.stringify(quoteIntentPayload),
  });
  const quoteData = await quoteRes.json();

  console.log("Quote Data: ", JSON.stringify(quoteData));

  // Process any ERC20 Approvals needed for the transaction
  if (quoteData.approvals.length > 0) {
    console.log("Granting one-time ERC20 Approvals to centralised Permit2 contract...");
    await Promise.all(
      quoteData.approvals.map((approval) =>
        wallet.sendTransaction({ to: approval.to, data: approval.data })
      )
    );
  }

  // Sign any Permit2 Data needed for the transaction
  let permitSignature = "";
  if (quoteData.permit2Datas) {
    console.log("Granting Permit2 allowance to Haiku Router to facilitate this trade...");

    // Helper code to convert BigNumber 'amount' values to string for EthersV6
    let permit2Values = quoteData.permit2Datas.values;
    if (Array.isArray(permit2Values.details)) {
      // Multiple input token case
      permit2Values.details = permit2Values.details.map(detail => ({
        ...detail,
        amount: BigInt(detail.amount.hex).toString(),
      }));
    } else if (permit2Values.details && permit2Values.details.amount) {
      // Single input token case
      permit2Values.details.amount = BigInt(permit2Values.details.amount.hex).toString();
    }

    // Sign the Permit2 data to grant allowances for this trade
    permitSignature = await wallet.signTypedData(
      quoteData.permit2Datas.domain,
      quoteData.permit2Datas.types,
      quoteData.permit2Datas.values
    );
  }

  // If the quote involves a complex post-bridge transaction, we sign for the destination bridge
  let userSignature;
  if (data.isComplexBridge) {
    const { unsignedTypeV4Digest } = data.destinationBridge;
    userSignature = await wallet._signTypedData(
      unsignedTypeV4Digest.domain,
      unsignedTypeV4Digest.types,
      unsignedTypeV4Digest.values
    );
    console.log(
      isValidSignature({
        domain: unsignedTypeV4Digest.domain,
        types: unsignedTypeV4Digest.types,
        message: unsignedTypeV4Digest.values,
        signature: userSignature,
        expectedAddress: wallet.address,
      })
    );
  }

  const quoteId = data.quoteId;

  const solveIntentPayload = {
    quoteId,
    userSignature,
    permit2Signature,
  };

  // Build and send the Intent transaction
  console.log("Building the unsigned EVM transaction to execute the Intent...");
  const solveRes = await fetch(`${haikuApiBaseUrl}/solveIntent`, {
    method: "POST",
    headers: headers,
    body: JSON.stringify(solveIntentPayload),
  });
  const unsignedTransactionRequest = await solveRes.json();
  console.log("Unsigned transaction received, signing and broadcasting on chain...");
  await wallet.sendTransaction(unsignedTransactionRequest);
  console.log("Completed, have a nice day :)");
}

main().catch(console.error);

⚡ Developer notes

• ERC-20 Approvals: Are required once for each input token per Permit2 contract.

• Permit2 Documentation: Details regarding the Permit2 Allowances model.