Jupiter Order Helper (JavaScript)

A resilient helper for building Jupiter swap transactions that automatically probes Ultra → Quote v6 → Lite endpoints, cools down rate-limited URLs, and can build both buy and sell legs with a single call.

Features

• Endpoint selection: probes Ultra first, then Quote v6, then Lite, with cooldown handling.
• Rate-limit awareness: cools endpoints on 429s and retries with backoff.
• Optional Nozomi/Temporal API key injection (if configured via env).
• Buy & sell builders: one call can return both directions.
• Legacy or v0 transaction support (auto-deserializes base64).

Install

npm install @solana/web3.js node-fetch

Usage

import { Connection, Keypair } from "@solana/web3.js";
import { buildBuySellTransactions } from "./jupiter.js"; // adjust path as needed

const connection = new Connection("https://api.mainnet-beta.solana.com", "confirmed");
const signer = Keypair.fromSecretKey(/* your secret key Uint8Array */);

const inputMint  = "So11111111111111111111111111111111111111112"; // SOL (wrapped)
const outputMint = "Es9vMFrzaCERmJfrF4H2FYD4KCoNkY11McCe8BenwNYB"; // USDT

const { buyTx, sellTx, buyOrder, sellOrder } = await buildBuySellTransactions({
  inputMint,
  outputMint,
  buyAmountNative: 1_000_000, // lamports or token native units
  sellAmountToken: 0,         // set if you want a sell leg too
  slippage: 1,                // percent → converted to bps internally
  signerKeypair: signer,
  connection,
  forceLegacy: false,
});

// Sign/serialize/send buyTx or sellTx as needed:
// const sig = await connection.sendTransaction(buyTx, [signer], { skipPreflight: false });

Environment Variables

• ULTRA_API_KEY: Jupiter Ultra API key (adds JUP-API-KEY/x-api-key headers).
• JUP_ENDPOINT_COOLDOWN_MS: override per-endpoint cooldown after 429 (default 6000).
• Optional Nozomi/Temporal passthrough:
  • USE_NOZOMI (true/false), NOZOMI_API_KEY / TEMPORAL_API_KEY
  • NOZOMI_ORDER_URL / NOZOMI_ENDPOINT / TEMPORAL_ORDER_URL / TEMPORAL_ENDPOINT

Notes

• Endpoint choice is cached unless cooled down; logs will indicate Ultra/QuoteV6/Lite.
• Amounts are expected in native units (e.g., lamports for SOL, token base units).
• slippage is provided as percent; code converts to basis points.
• For signing, recent blockhash and fee payer are applied automatically before partial sign.

License

MIT (see root LICENSE).