滑點與價格影響

p_before = pool.spot_price()
p_after  = pool.spot_price_if_trade(Δin) applied
impact   = (p_before − p_after) / p_before       // 可以帶符號

quoted_out = 報價時計算的 amount_out
actual_out = 鏈上觀察到的 amount_out
slippage   = (quoted_out − actual_out) / quoted_out

// AMM v4 — 唯一有字面上稱為 computeAmountOut 的方法的模組
const computed = raydium.liquidity.computeAmountOut({
  poolInfo,            // 需要 baseReserve/quoteReserve/version/status 拼接
  amountIn,            // BN
  mintIn,
  mintOut,
  slippage: 0.005,     // 0.5% 容差，純數字
});
// -> { amountOut, minAmountOut, currentPrice, executionPrice, priceImpact, fee }
//    所有金額都是純 BN

// CPMM
const { computePoolInfo } = await raydium.cpmm.getPoolInfoFromRpc(POOL_ID);
const cpmmQuote = raydium.cpmm.computeSwapAmount({
  pool: computePoolInfo, amountIn, outputMint: mintOut, slippage: 0.005,
});
// -> { amountIn, amountOut, minAmountOut, fee, executionPrice, priceImpact, swapResult, allTrade }

// CLMM — 一個 PoolUtils 靜態方法，需要位圖擴展 + 區塊時間戳
const clmmQuote = PoolUtils.computeAmountOutFormat({
  poolInfo: computeClmmPoolInfo, tickarrayBitmapExtension, tickArrayCache,
  amountIn, tokenOut, slippage: 0.005,
  epochInfo: await raydium.fetchEpochInfo(),
  blockTimestamp: Math.floor(Date.now() / 1000),
});
// -> { amountOut, minAmountOut, fee, priceImpact, remainingAccounts, ... }

// 不好：0.5% 僅在末尾應用，所以任何中間跳滑動都會導致第二跳失敗。
const finalMin = finalAmount * (1 - 0.005);

// 更好：每跳強制執行自己的邊界。
const hop1Min  = hop1Amount * (1 - 0.005);
const hop2Min  = hop2Amount * (1 - 0.005);
// 端到端這更緊密（複合），但是原子的——如果任一跳降級，交易會提前回滾。