TradeFutures

This instruction opens a futures position (e.g. LONG or SHORT) and creates:

• A new Deal PDA
• A Position PDA (if not already existing)
• Updates orderbook state
• Updates pool + user state

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Instruction Discriminator

const TRADE_FUTURES_TAG = 7;

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Helper: writeU128LE

function writeU128LE(value: string): Buffer {
  const bn = BigInt(value);
  const buf = Buffer.alloc(16);
  let remaining = bn;

  for (let i = 0; i < 16; i++) {
    buf[i] = Number(remaining & BigInt(0xff));
    remaining >>= BigInt(8);
  }

  return buf;
}

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TradeFutures Instruction Builder

function createTradeFuturesInstruction(
  programId: PublicKey,
  keeper: PublicKey,
  taker: PublicKey,
  userAccountPda: PublicKey,
  assetPda: PublicKey,
  poolPda: PublicKey,
  poolPdas: PoolPDAs,
  configPda: PublicKey,
  orderbookState: PublicKey,
  currentDealId: number,
  pair: string,
  amount: string,
  price: string,
  orderType: number,
  direction: number,
  goodTill: string,
  rewardGas: string
): TransactionInstruction {

  const pairBytes = Buffer.from(pair, 'utf-8');
  const pairLengthBuffer = Buffer.alloc(4);
  pairLengthBuffer.writeUInt32LE(pairBytes.length, 0);

  const goodTillBuf = Buffer.alloc(8);
  goodTillBuf.writeBigInt64LE(BigInt(goodTill), 0);

  const rewardGasBuf = Buffer.alloc(8);
  rewardGasBuf.writeBigUInt64LE(BigInt(rewardGas), 0);

  const data = Buffer.concat([
    Buffer.from([TRADE_FUTURES_TAG]),
    pairLengthBuffer,
    pairBytes,
    writeU128LE(amount),
    writeU128LE(price),
    Buffer.from([orderType]),
    Buffer.from([direction]),
    goodTillBuf,
    taker.toBuffer(),
    rewardGasBuf,
  ]);

  const [dealPda] = findDealAddress(programId, currentDealId);
  const [positionPda] = findPositionAddress(programId, taker, pair, direction);

  return new TransactionInstruction({
    keys: [
      { pubkey: keeper, isSigner: true, isWritable: true },               // 0
      { pubkey: assetPda, isSigner: false, isWritable: false },           // 1
      { pubkey: configPda, isSigner: false, isWritable: true },           // 2
      { pubkey: taker, isSigner: false, isWritable: false },              // 3
      { pubkey: userAccountPda, isSigner: false, isWritable: true },      // 4
      { pubkey: poolPda, isSigner: false, isWritable: true },             // 5
      { pubkey: poolPdas.makers, isSigner: false, isWritable: true },     // 6
      { pubkey: poolPdas.liquidityMarkets, isSigner: false, isWritable: true }, // 7
      { pubkey: poolPdas.positions, isSigner: false, isWritable: true },  // 8
      { pubkey: poolPdas.userDeals, isSigner: false, isWritable: true },  // 9
      { pubkey: orderbookState, isSigner: false, isWritable: true },      // 10
      { pubkey: dealPda, isSigner: false, isWritable: true },             // 11
      { pubkey: positionPda, isSigner: false, isWritable: true },         // 12
      { pubkey: SystemProgram.programId, isSigner: false, isWritable: false }, // 13
      { pubkey: SYSVAR_RENT_PUBKEY, isSigner: false, isWritable: false }, // 14
      { pubkey: SYSVAR_CLOCK_PUBKEY, isSigner: false, isWritable: false }, // 15
      { pubkey: poolPdas.matchIds, isSigner: false, isWritable: true },   // 16
      { pubkey: poolPdas.keepers, isSigner: false, isWritable: false },   // 17
    ],
    programId,
    data,
  });
}

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Required Account Order (Critical)

The account order must match the Rust open_order / trade_futures processor exactly:

Index	Account
0	keeper (signer)
1	asset PDA
2	config PDA
3	taker
4	user account PDA
5	pool PDA
6	makers PDA
7	liquidity markets PDA
8	positions PDA
9	user deals PDA
10	orderbook state
11	deal PDA
12	position PDA
13	system program
14	rent sysvar
15	clock sysvar
16	match ids PDA
17	keepers PDA

If the order differs, deserialization will fail or produce invalid bool / UnsupportedAsset errors.

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Data Layout (Binary Encoding)

The instruction data is encoded as:

u8      instruction_tag (7)
u32     pair_length
bytes   pair_string
u128    amount
u128    price
u8      order_type
u8      direction
i64     good_till
Pubkey  taker
u64     reward_gas

All numeric values must be little-endian.

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