fix pumpfun native sol quote routing

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sol-trade-sdk"
-version = "4.0.19"
+version = "4.0.20"
 edition = "2021"
 authors = [
     "William <byteblock6@gmail.com>",

README.md

@@ -83,11 +83,11 @@ This SDK is available in multiple languages:
 
 **Rust crate:** `sol-trade-sdk = "4.0.17"`
 
-This release refreshes PumpFun V2 WSOL quote-pool handling, keeps the default RPC submit lane active alongside SWQoS lanes, restores the fast-submit result window to 5 seconds, and aligns Raydium CPMM fixed-output swaps with the on-chain `swap_base_out` instruction. Trade execution requires a caller-supplied `recent_blockhash` or durable nonce; hot-path execution does not query RPC for blockhash, account, or balance data.
+This release refreshes PumpFun native-SOL quote handling so SOL/WSOL sentinels prefer the smaller V1 hot path, keeps the default RPC submit lane active alongside SWQoS lanes, restores the fast-submit result window to 5 seconds, and aligns Raydium CPMM fixed-output swaps with the on-chain `swap_base_out` instruction. Trade execution requires a caller-supplied `recent_blockhash` or durable nonce; hot-path execution does not query RPC for blockhash, account, or balance data.
 
 ## ✨ Features
 
-1. **PumpFun Trading**: Unified SDK-side `buy`, `sell`, and `buy_exact_quote_in` flow, selecting legacy or V2 on-chain instructions as needed (SOL/WSOL + USDC)
+1. **PumpFun Trading**: Unified SDK-side `buy`, `sell`, and `buy_exact_quote_in` flow, preferring V1 for native SOL and selecting V2 for USDC/non-native quote mints or explicit WSOL settlement
 2. **PumpSwap Trading**: Support for PumpSwap pool trading operations
 3. **Bonk Trading**: Support for Bonk trading operations
 4. **Raydium CPMM Trading**: Support for Raydium CPMM (Concentrated Pool Market Maker) trading operations
@@ -426,15 +426,15 @@ PumpFun has two instruction sets for bonding-curve trading:
 |---|---|---|
 | Instructions | `buy` / `buy_exact_sol_in` / `sell` | `buy_v2` / `buy_exact_quote_in_v2` / `sell_v2` |
 | Account metas | 18 | 27 |
-| Quote mint | SOL only (legacy) | SOL or USDC (via `quote_mint` field) |
-| Transaction size | Smaller (fits `PACKET_DATA_SIZE` without LUT) | Larger (requires LUT for most transactions) |
+| Quote mint | Native SOL (`default`, Solscan SOL sentinel, or WSOL sentinel) | Non-native quote mint, or explicit WSOL settlement |
+| Transaction size | Smaller (preferred hot path) | Larger (may require LUT for nonce/tip/ATA-heavy transactions) |
 
-The SDK-side builder is version-neutral: callers use the normal buy/sell flow, and `quote_mint` selects the correct on-chain discriminator and account layout internally. There is no user-facing V2 switch required.
+The SDK-side builder is version-neutral: callers use the normal buy/sell flow, and `quote_mint` plus the requested settlement token (`pay_with` / `receive_as`) select the correct on-chain discriminator and account layout internally. There is no user-facing V2 switch required.
 
-**Default: V1**. When `quote_mint` is `Pubkey::default()` or the Solscan SOL sentinel (`So11111111111111111111111111111111111111111`), the SDK uses V1 instructions which produce smaller transactions that fit within the 1232-byte `PACKET_DATA_SIZE` limit without requiring an Address Lookup Table. Passing `WSOL_TOKEN_ACCOUNT` selects SOL V2; passing USDC selects USDC V2.
+**Default: V1**. When `quote_mint` is `Pubkey::default()`, the Solscan SOL sentinel (`So11111111111111111111111111111111111111111`), or `WSOL_TOKEN_ACCOUNT` (`So11111111111111111111111111111111111111112`), the SDK treats the curve as native SOL-paired and uses V1 instructions when `pay_with` / `receive_as` is `SOL`. This is the preferred hot path because it avoids the 27-account V2 layout. Passing USDC or another real quote mint selects V2. Passing `WSOL` as the buy input or sell output selects V2 only when you intentionally want to settle through an existing WSOL ATA.
 
 **Key changes in v2 instructions:**
-- `quote_mint` parameter — pass wrapped SOL for SOL-paired, or USDC mint for USDC-paired
+- `quote_mint` parameter — native SOL-paired curves may appear as default, Solscan SOL, or WSOL; USDC/non-native quote mints select V2
 - 27 fixed accounts (buy) / 26 fixed accounts (sell) — **no optional accounts**
 - `buyback_fee_recipient`, `sharing_config`, and 6 `associated_quote_*` ATAs are now mandatory
 - Same pricing and cost as legacy instructions for SOL-paired coins
@@ -442,13 +442,12 @@ The SDK-side builder is version-neutral: callers use the normal buy/sell flow, a
 
 **Pass `quote_mint` into `PumpFunParams::from_trade`**:
 
-When using event/parser data, pass the event's `quote_mint` right after `mint`. `Pubkey::default()` and Solscan SOL (`So11111111111111111111111111111111111111111`) mean the legacy SOL layout; `WSOL_TOKEN_ACCOUNT` means SOL V2; USDC means USDC V2.
+When using event/parser data, pass the event's `quote_mint` right after `mint`. `Pubkey::default()`, Solscan SOL (`So11111111111111111111111111111111111111111`), and `WSOL_TOKEN_ACCOUNT` all mean a native SOL-paired curve and default to V1 for normal SOL settlement. USDC means USDC V2.
 
 ```rust
 // quote_mint is not a PDA. It is the quote SPL mint carried by parser/gRPC events:
-// - Legacy SOL pool: Pubkey::default() or Solscan SOL from parser data
-// - SOL V2 pool: WSOL_TOKEN_ACCOUNT
-// - USDC V2 pool: USDC mint
+// - Native SOL pool: Pubkey::default(), Solscan SOL, or WSOL sentinel from parser data
+// - USDC/non-native pool: actual quote SPL mint
 let quote_mint = e.quote_mint;
 let params = PumpFunParams::from_trade(
     e.bonding_curve,
@@ -469,11 +468,11 @@ let params = PumpFunParams::from_trade(
 );
 ```
 
-For USDC-paired coins, pass `USDC_TOKEN_ACCOUNT` as the buy `input_mint` and sell `output_mint`; SOL/WSOL is only valid for SOL-paired PumpFun curves.
+For USDC-paired coins, pass `USDC_TOKEN_ACCOUNT` as the buy `input_mint` and sell `output_mint`; SOL/WSOL is only valid for SOL-paired PumpFun curves. For SOL-paired curves, use `SOL` for the normal fast path; use `WSOL` only if you intentionally want V2 settlement through an existing WSOL ATA.
 When consuming parser events, map `quoteMint`, `virtualQuoteReserves`, and `realQuoteReserves` into `PumpFunParams::from_trade(...)`; USDC pools use `4_292_000_000` as the initial virtual quote reserve.
 For legacy SOL events where `quote_mint` is `Pubkey::default()` or Solscan SOL, use `virtual_sol_reserves` / `real_sol_reserves` when the quote-reserve fields are absent or zero.
 
-> **Note**: V2 transactions with ATA creation + durable nonce may exceed `PACKET_DATA_SIZE`. Enable an Address Lookup Table (`address_lookup_table_account`) when using V2.
+> **Note**: V2 transactions with ATA creation + durable nonce/tip may exceed `PACKET_DATA_SIZE`. The SDK reports this locally and does not remove compute-budget or tip instructions because that changes priority semantics. Use V1 when the curve is native SOL-paired, pre-create ATAs, or enable an Address Lookup Table (`address_lookup_table_account`) when using V2.
 
 #### PumpSwap: coin_creator_vault from events (no RPC)
 

README_CN.md

@@ -83,11 +83,11 @@
 
 **Rust crate:** `sol-trade-sdk = "4.0.17"`
 
-本版本刷新 PumpFun V2 WSOL quote 池处理逻辑，确保默认 RPC 提交通道会和 SWQoS 通道一起发出，快速提交结果等待窗口恢复为 5 秒，并将 Raydium CPMM fixed-output 交易对齐到链上 `swap_base_out` 指令。交易执行必须由调用方传入 `recent_blockhash` 或 durable nonce；热路径不会查询 RPC 获取 blockhash、账户或余额数据。
+本版本刷新 PumpFun native SOL quote 处理逻辑，SOL/WSOL sentinel 默认优先走更小的 V1 热路径，确保默认 RPC 提交通道会和 SWQoS 通道一起发出，快速提交结果等待窗口恢复为 5 秒，并将 Raydium CPMM fixed-output 交易对齐到链上 `swap_base_out` 指令。交易执行必须由调用方传入 `recent_blockhash` 或 durable nonce；热路径不会查询 RPC 获取 blockhash、账户或余额数据。
 
 ## ✨ 项目特性
 
-1. **PumpFun 交易**: SDK 侧统一为 `buy`、`sell`、`buy_exact_quote_in` 流程，内部按需选择旧版或 V2 链上指令（SOL/WSOL + USDC）
+1. **PumpFun 交易**: SDK 侧统一为 `buy`、`sell`、`buy_exact_quote_in` 流程，native SOL 优先走 V1，USDC/非 SOL quote 或显式 WSOL 结算才走 V2
 2. **PumpSwap 交易**: 支持 PumpSwap 池的交易操作
 3. **Bonk 交易**: 支持 Bonk 的交易操作
 4. **Raydium CPMM 交易**: 支持 Raydium CPMM (Concentrated Pool Market Maker) 的交易操作
@@ -428,22 +428,21 @@ SDK 不会在每次卖出时通过 RPC 拉取 creator_vault（以避免延迟）
 
 Pump.fun 已升级 Bonding Curve 合约，推出**统一化 v2 指令**，通过固定账户布局同时支持 SOL 和 USDC 配对币。旧版 `buy`/`sell`/`buy_exact_sol_in` 仍可用于 SOL 配对币，且保持为默认选项。
 
-SDK 侧调用入口保持统一：正常使用 `buy` / `sell` 流程即可，SDK 会根据 `quote_mint` 自动选择正确的链上 discriminator 和账户布局。
+SDK 侧调用入口保持统一：正常使用 `buy` / `sell` 流程即可，SDK 会根据 `quote_mint` 和买/卖的结算 mint 自动选择正确的链上 discriminator 和账户布局。能用 V1 的 native SOL 池会优先用 V1。
 
 **v2 指令关键变化：**
-- 新增 `quote_mint` 参数 — SOL 配对传包装 SOL（`So11111111111111111111111111111111111111112`），USDC 配对传 USDC mint
+- 新增 `quote_mint` 参数 — native SOL 配对可能表现为默认值、Solscan SOL sentinel（`So11111111111111111111111111111111111111111`）或 WSOL sentinel（`So11111111111111111111111111111111111111112`）；USDC/其他真实 quote mint 才选择 V2
 - 27 个固定账户（buy）/ 26 个固定账户（sell）— **无可选账户**
 - `buyback_fee_recipient`、`sharing_config` 和 6 个 `associated_quote_*` ATA 变为强制账户
 - SOL 配对币的报价和成本与旧版一致，无额外开销
 
 **使用方式：**
 
-把事件里的 `quote_mint` 传给 `PumpFunParams::from_trade`。`quote_mint` 不是 PDA，它就是 quote SPL mint；`Pubkey::default()` 和 Solscan SOL（`So11111111111111111111111111111111111111111`）表示旧版 SOL 布局，`WSOL_TOKEN_ACCOUNT` 表示 SOL V2，USDC 表示 USDC V2：
+把事件里的 `quote_mint` 传给 `PumpFunParams::from_trade`。`quote_mint` 不是 PDA，它就是 quote SPL mint 或 native SOL sentinel；`Pubkey::default()`、Solscan SOL（`So11111111111111111111111111111111111111111`）和 `WSOL_TOKEN_ACCOUNT` 都表示 native SOL 配对，正常用 SOL 结算时默认走旧版 V1；USDC 表示 USDC V2：
 
 ```rust
-// legacy SOL 池：log 事件里可能是 Pubkey::default()，parser 数据里是 Solscan SOL sentinel
-// SOL V2 池：WSOL_TOKEN_ACCOUNT
-// USDC 池：就是 USDC mint
+// native SOL 池：可能是 Pubkey::default()、Solscan SOL sentinel 或 WSOL sentinel
+// USDC / 非 SOL 池：就是实际 quote SPL mint
 let quote_mint = e.quote_mint;
 
 let params = PumpFunParams::from_trade(
@@ -469,14 +468,14 @@ client.buy(buy_params).await?;
 client.sell(sell_params).await?;
 ```
 
-USDC 配对币必须用 USDC 买入、卖出也结算为 USDC；SOL/WSOL 只适用于 SOL 配对的 PumpFun 曲线。SDK 会在提交前拒绝 USDC quote 池的 SOL 输入，避免链上 6063 失败。
+USDC 配对币必须用 USDC 买入、卖出也结算为 USDC；SOL/WSOL 只适用于 SOL 配对的 PumpFun 曲线。SOL 配对的普通热路径请传 `SOL`，SDK 会用 V1；只有你明确传 `WSOL` 作为买入输入或卖出输出、希望通过已有 WSOL ATA 结算时，才会选择 V2。
+SDK 会在提交前拒绝 USDC quote 池的 SOL 输入，避免链上 6063 失败。
 消费 parser 事件时，需要把 `quoteMint`、`virtualQuoteReserves`、`realQuoteReserves` 传进 `PumpFunParams::from_trade(...)`；USDC 池初始虚拟 quote reserve 是 `4_292_000_000`。
 legacy SOL 事件里如果 `quote_mint` 是默认值或 Solscan SOL，并且 quote reserve 字段缺失/为 0，应回退使用 `virtual_sol_reserves` / `real_sol_reserves`。
 
 | quote_mint | 实际使用的指令 | 说明 |
 |-----------|---------|------|
-| 未设置（默认）/ `SOL_TOKEN_ACCOUNT` (`So111...11111`) | 旧版 `buy`/`sell`/`buy_exact_sol_in` | 向后兼容，仅 SOL |
-| `WSOL_TOKEN_ACCOUNT` (`So111...11112`) | `buy_v2`/`sell_v2`/`buy_exact_quote_in_v2` | SOL 配对，统一布局 |
+| 未设置（默认）/ `SOL_TOKEN_ACCOUNT` (`So111...11111`) / `WSOL_TOKEN_ACCOUNT` (`So111...11112`) | 优先旧版 `buy`/`sell`/`buy_exact_sol_in` | native SOL 配对；普通 SOL 结算走 V1，显式 WSOL 结算才走 V2 |
 | `USDC_TOKEN_ACCOUNT` | `buy_v2`/`sell_v2`/`buy_exact_quote_in_v2` | USDC 配对（必须使用 v2） |
 
 ## 🛡️ MEV 保护服务

src/client/mod.rs

@@ -173,9 +173,10 @@ pub struct SimpleBuyParams {
     pub dex_type: DexType,
     /// Quote token used to pay for the buy: `SOL`, `WSOL`, `USDC`, or `USD1`.
     ///
-    /// For PumpFun V2 SOL-paired coins, use `TradeTokenType::SOL` even when the
-    /// protocol quote mint account is WSOL. The SDK passes WSOL as the V2 quote
-    /// account but keeps settlement in native SOL.
+    /// For PumpFun SOL-paired coins, use `TradeTokenType::SOL` for the normal
+    /// fast path even when parser data reports WSOL as the quote sentinel. The
+    /// SDK will prefer V1; choose `WSOL` only when intentionally spending an
+    /// existing WSOL ATA through V2.
     pub pay_with: TradeTokenType,
     /// Mint address of the token being bought.
     pub mint: Pubkey,

src/instruction/pumpfun.rs

@@ -1,10 +1,11 @@
 //! Pump.fun bonding-curve swap ix assembly ([`SwapParams`](crate::trading::core::params::SwapParams)).
 //!
 //! The SDK selects the legacy or V2 on-chain layout from `PumpFunParams.quote_mint`.
-//! `Pubkey::default()` and the Solscan SOL sentinel keep the smaller legacy SOL layout;
-//! explicit WSOL or USDC uses the V2 27/26-account unified metas.
-//! Default (`false`) keeps the smaller legacy SOL-paired instruction layout for latency.
+//! Native SOL-paired coins (`Pubkey::default()`, Solscan SOL sentinel, or WSOL sentinel)
+//! keep the smaller legacy SOL layout by default. Non-native quote mints such as USDC use
+//! the V2 27/26-account unified metas.
 
+use crate::swqos::TradeType;
 use crate::{
     common::bonding_curve::BondingCurveAccount,
     common::spl_token::close_account,
@@ -52,8 +53,8 @@ fn effective_pump_mint_token_program(protocol_params: &PumpFunParams, mint: &Pub
 }
 
 /// Resolve quote mint and its token program from PumpFunParams.
-/// `Pubkey::default()` / `SOL_TOKEN_ACCOUNT` means legacy SOL-paired; use WSOL mint when a
-/// downstream V2 helper needs a concrete SPL quote mint.
+/// `Pubkey::default()` / `SOL_TOKEN_ACCOUNT` / `WSOL_TOKEN_ACCOUNT` are native SOL-paired.
+/// V2 helpers still need a concrete SPL mint, so native SOL resolves to WSOL internally.
 #[inline]
 fn effective_quote_mint_and_token_program(protocol_params: &PumpFunParams) -> (Pubkey, Pubkey) {
     let curve_quote_mint = protocol_params.bonding_curve.effective_quote_mint();
@@ -73,6 +74,16 @@ fn is_sol_quote_mint(quote_mint: &Pubkey) -> bool {
         || *quote_mint == crate::constants::SOL_TOKEN_ACCOUNT
 }
 
+#[inline]
+fn is_native_sol_settlement_mint(mint: &Pubkey) -> bool {
+    *mint == crate::constants::SOL_TOKEN_ACCOUNT || *mint == Pubkey::default()
+}
+
+#[inline]
+fn is_explicit_wsol_settlement_mint(mint: &Pubkey) -> bool {
+    *mint == crate::constants::WSOL_TOKEN_ACCOUNT
+}
+
 #[inline]
 fn validate_v2_buy_quote_mint(input_mint: &Pubkey, quote_mint: &Pubkey) -> Result<()> {
     if is_sol_quote_mint(quote_mint) {
@@ -130,9 +141,20 @@ fn should_use_v2_layout(params: &SwapParams) -> Result<bool> {
         .downcast_ref::<PumpFunParams>()
         .ok_or_else(|| anyhow!("Invalid protocol params for PumpFun"))?;
     let (quote_mint, _) = effective_quote_mint_and_token_program(protocol_params);
-    let explicit_v2_quote = protocol_params.quote_mint != Pubkey::default()
-        && protocol_params.quote_mint != crate::constants::SOL_TOKEN_ACCOUNT;
-    Ok(explicit_v2_quote || !is_sol_quote_mint(&quote_mint))
+    if !is_sol_quote_mint(&quote_mint) {
+        return Ok(true);
+    }
+
+    // Pump docs treat WSOL quote mint as the native SOL sentinel for SOL-paired curves.
+    // Keep V1 for native SOL settlement; use V2 only when the caller explicitly wants to
+    // spend/receive an existing WSOL ATA.
+    Ok(match params.trade_type {
+        TradeType::Buy | TradeType::CreateAndBuy => {
+            is_explicit_wsol_settlement_mint(&params.input_mint)
+        }
+        TradeType::Sell => is_explicit_wsol_settlement_mint(&params.output_mint),
+        TradeType::Create => false,
+    })
 }
 
 #[inline]
@@ -171,6 +193,13 @@ fn build_buy_legacy(params: &SwapParams) -> Result<Vec<Instruction>> {
         .downcast_ref::<PumpFunParams>()
         .ok_or_else(|| anyhow!("Invalid protocol params for PumpFun"))?;
 
+    if !is_native_sol_settlement_mint(&params.input_mint) {
+        return Err(anyhow!(
+            "PumpFun native SOL buy expects input_mint SOL; got {}. Use the matching non-native quote mint for V2 pools or WSOL input only when spending an existing WSOL ATA.",
+            params.input_mint
+        ));
+    }
+
     let lamports_in = params.input_amount.unwrap_or(0);
     if lamports_in == 0 {
         return Err(anyhow!("Amount cannot be zero"));
@@ -299,6 +328,13 @@ fn build_sell_legacy(params: &SwapParams) -> Result<Vec<Instruction>> {
         .downcast_ref::<PumpFunParams>()
         .ok_or_else(|| anyhow!("Invalid protocol params for PumpFun"))?;
 
+    if !is_native_sol_settlement_mint(&params.output_mint) {
+        return Err(anyhow!(
+            "PumpFun native SOL sell expects output_mint SOL; got {}. Use the matching non-native quote mint for V2 pools or WSOL output only when receiving into an existing WSOL ATA.",
+            params.output_mint
+        ));
+    }
+
     let token_amount = if let Some(amount) = params.input_amount {
         if amount == 0 {
             return Err(anyhow!("Amount cannot be zero"));
@@ -1002,14 +1038,15 @@ mod tests {
     }
 
     #[test]
-    fn pumpfun_v2_fixed_output_uses_buy_with_max_input_budget() {
+    fn pumpfun_v2_usdc_fixed_output_uses_buy_with_max_input_budget() {
         let mut params = swap_params_for_buy(pump_mint(), TOKEN_PROGRAM);
         params.create_output_mint_ata = false;
+        params.input_mint = crate::constants::USDC_TOKEN_ACCOUNT;
         params.fixed_output_amount = Some(42);
         params.use_exact_sol_amount = Some(true);
         if let DexParamEnum::PumpFun(protocol_params) = &mut params.protocol_params {
             *protocol_params =
-                protocol_params.clone().with_quote_mint(crate::constants::WSOL_TOKEN_ACCOUNT);
+                protocol_params.clone().with_quote_mint(crate::constants::USDC_TOKEN_ACCOUNT);
         }
 
         let instructions = build_buy(&params).unwrap();
@@ -1024,7 +1061,7 @@ mod tests {
     }
 
     #[test]
-    fn pumpfun_v2_regular_buy_uses_native_sol_for_wsol_quote() {
+    fn pumpfun_wsol_quote_regular_buy_uses_v1_native_sol() {
         let mut params = swap_params_for_buy(pump_mint(), TOKEN_PROGRAM);
         params.create_output_mint_ata = false;
         params.create_input_mint_ata = true;
@@ -1043,13 +1080,13 @@ mod tests {
             params.slippage_basis_points.unwrap(),
         );
 
-        assert_eq!(&buy_ix.data[..8], crate::instruction::utils::pumpfun::BUY_V2_DISCRIMINATOR);
+        assert_eq!(&buy_ix.data[..8], crate::instruction::utils::pumpfun::BUY_DISCRIMINATOR);
         assert_eq!(u64::from_le_bytes(buy_ix.data[16..24].try_into().unwrap()), expected);
-        assert_eq!(buy_ix.accounts.len(), 27);
+        assert_eq!(buy_ix.accounts.len(), 18);
     }
 
     #[test]
-    fn pumpfun_v2_regular_buy_skips_wsol_ata_create_on_hot_path() {
+    fn pumpfun_wsol_quote_regular_buy_skips_wsol_ata_create_on_hot_path() {
         let mut params = swap_params_for_buy(pump_mint(), TOKEN_PROGRAM);
         params.create_output_mint_ata = false;
         params.create_input_mint_ata = true;
@@ -1065,13 +1102,15 @@ mod tests {
         assert_eq!(instructions.len(), 1);
         assert_eq!(
             &instructions.last().unwrap().data[..8],
-            crate::instruction::utils::pumpfun::BUY_V2_DISCRIMINATOR
+            crate::instruction::utils::pumpfun::BUY_DISCRIMINATOR
         );
     }
 
     #[test]
-    fn pumpfun_v2_wsol_quote_hot_path_transaction_fits_packet_with_output_ata_create() {
+    fn pumpfun_v2_explicit_wsol_input_with_output_ata_create_reports_oversized_without_dropping_priority(
+    ) {
         let mut params = swap_params_for_buy(pump_mint(), TOKEN_PROGRAM);
+        params.input_mint = crate::constants::WSOL_TOKEN_ACCOUNT;
         params.create_input_mint_ata = true;
         params.create_output_mint_ata = true;
         params.use_exact_sol_amount = Some(false);
@@ -1080,6 +1119,41 @@ mod tests {
                 protocol_params.clone().with_quote_mint(crate::constants::WSOL_TOKEN_ACCOUNT);
         }
 
+        let business_instructions = build_buy(&params).unwrap();
+        let err = crate::trading::common::transaction_builder::build_transaction(
+            &params.payer,
+            150_000,
+            500_000,
+            &business_instructions,
+            None,
+            Some(solana_hash::Hash::new_unique()),
+            None,
+            "PumpFun",
+            true,
+            true,
+            &Pubkey::new_unique(),
+            0.001,
+            None,
+        )
+        .unwrap_err()
+        .to_string();
+
+        assert!(err.contains("transaction too large"), "{err}");
+        assert!(err.contains("did not remove compute budget or relay tip"), "{err}");
+    }
+
+    #[test]
+    fn pumpfun_v2_explicit_wsol_input_hot_path_transaction_fits_when_output_ata_prepared() {
+        let mut params = swap_params_for_buy(pump_mint(), TOKEN_PROGRAM);
+        params.input_mint = crate::constants::WSOL_TOKEN_ACCOUNT;
+        params.create_input_mint_ata = true;
+        params.create_output_mint_ata = false;
+        params.use_exact_sol_amount = Some(false);
+        if let DexParamEnum::PumpFun(protocol_params) = &mut params.protocol_params {
+            *protocol_params =
+                protocol_params.clone().with_quote_mint(crate::constants::WSOL_TOKEN_ACCOUNT);
+        }
+
         let business_instructions = build_buy(&params).unwrap();
         let transaction = crate::trading::common::transaction_builder::build_transaction(
             &params.payer,
@@ -1107,7 +1181,7 @@ mod tests {
     }
 
     #[test]
-    fn pumpfun_from_trade_wsol_quote_regular_buy_selects_buy_v2() {
+    fn pumpfun_from_trade_wsol_quote_regular_buy_selects_v1() {
         let mint = pump_mint();
         let mut params = swap_params_for_buy(mint, TOKEN_PROGRAM);
         params.create_output_mint_ata = false;
@@ -1135,8 +1209,8 @@ mod tests {
         let instructions = build_buy(&params).unwrap();
         let buy_ix = instructions.last().unwrap();
 
-        assert_eq!(&buy_ix.data[..8], crate::instruction::utils::pumpfun::BUY_V2_DISCRIMINATOR);
-        assert_eq!(buy_ix.accounts.len(), 27);
+        assert_eq!(&buy_ix.data[..8], crate::instruction::utils::pumpfun::BUY_DISCRIMINATOR);
+        assert_eq!(buy_ix.accounts.len(), 18);
     }
 
     #[test]
@@ -1161,6 +1235,44 @@ mod tests {
         assert_eq!(instructions[0].accounts.len(), 27);
     }
 
+    #[test]
+    fn pumpfun_sell_does_not_select_v2_from_base_mint_wsol() {
+        let mut params = swap_params_for_buy(crate::constants::WSOL_TOKEN_ACCOUNT, TOKEN_PROGRAM);
+        params.trade_type = crate::swqos::TradeType::Sell;
+        params.input_mint = crate::constants::WSOL_TOKEN_ACCOUNT;
+        params.output_mint = crate::constants::SOL_TOKEN_ACCOUNT;
+        params.create_output_mint_ata = false;
+        if let DexParamEnum::PumpFun(protocol_params) = &mut params.protocol_params {
+            *protocol_params =
+                protocol_params.clone().with_quote_mint(crate::constants::WSOL_TOKEN_ACCOUNT);
+        }
+
+        let instructions = build_sell(&params).unwrap();
+        let ix = instructions.last().unwrap();
+
+        assert_eq!(&ix.data[..8], crate::instruction::utils::pumpfun::SELL_DISCRIMINATOR);
+    }
+
+    #[test]
+    fn pumpfun_sell_selects_v2_for_explicit_wsol_output_settlement() {
+        let mint = pump_mint();
+        let mut params = swap_params_for_buy(mint, TOKEN_PROGRAM);
+        params.trade_type = crate::swqos::TradeType::Sell;
+        params.input_mint = mint;
+        params.output_mint = crate::constants::WSOL_TOKEN_ACCOUNT;
+        params.create_output_mint_ata = false;
+        if let DexParamEnum::PumpFun(protocol_params) = &mut params.protocol_params {
+            *protocol_params =
+                protocol_params.clone().with_quote_mint(crate::constants::WSOL_TOKEN_ACCOUNT);
+        }
+
+        let instructions = build_sell(&params).unwrap();
+        let ix = instructions.last().unwrap();
+
+        assert_eq!(&ix.data[..8], crate::instruction::utils::pumpfun::SELL_V2_DISCRIMINATOR);
+        assert_eq!(ix.accounts.len(), 26);
+    }
+
     #[test]
     fn pumpfun_usdc_dev_trade_uses_usdc_initial_quote_reserves() {
         let mint = pump_mint();
@@ -1372,13 +1484,14 @@ mod tests {
     }
 
     #[test]
-    fn pumpfun_v2_buyback_fee_recipient_is_writable() {
+    fn pumpfun_v2_usdc_buyback_fee_recipient_is_writable() {
         let mint = pump_mint();
         let mut params = swap_params_for_buy(mint, TOKEN_PROGRAM);
         params.create_output_mint_ata = false;
+        params.input_mint = crate::constants::USDC_TOKEN_ACCOUNT;
         if let DexParamEnum::PumpFun(protocol_params) = &mut params.protocol_params {
             *protocol_params =
-                protocol_params.clone().with_quote_mint(crate::constants::WSOL_TOKEN_ACCOUNT);
+                protocol_params.clone().with_quote_mint(crate::constants::USDC_TOKEN_ACCOUNT);
         }
 
         let buy_ix = build_buy(&params).unwrap().pop().unwrap();
@@ -1387,7 +1500,7 @@ mod tests {
 
         params.trade_type = crate::swqos::TradeType::Sell;
         params.input_mint = mint;
-        params.output_mint = crate::constants::SOL_TOKEN_ACCOUNT;
+        params.output_mint = crate::constants::USDC_TOKEN_ACCOUNT;
         let sell_ix = build_sell(&params).unwrap().pop().unwrap();
         assert!(global_constants::BUYBACK_FEE_RECIPIENTS.contains(&sell_ix.accounts[8].pubkey));
         assert!(sell_ix.accounts[8].is_writable);
@@ -1416,17 +1529,17 @@ mod tests {
     }
 
     #[test]
-    fn pumpfun_v2_sell_fixed_output_uses_min_sol_directly() {
+    fn pumpfun_v2_usdc_sell_fixed_output_uses_min_quote_directly() {
         let mint = pump_mint();
         let mut params = swap_params_for_buy(mint, TOKEN_PROGRAM);
         params.trade_type = crate::swqos::TradeType::Sell;
         params.input_mint = mint;
-        params.output_mint = crate::constants::SOL_TOKEN_ACCOUNT;
+        params.output_mint = crate::constants::USDC_TOKEN_ACCOUNT;
         params.create_output_mint_ata = false;
         params.fixed_output_amount = Some(42);
         if let DexParamEnum::PumpFun(protocol_params) = &mut params.protocol_params {
             *protocol_params =
-                protocol_params.clone().with_quote_mint(crate::constants::WSOL_TOKEN_ACCOUNT);
+                protocol_params.clone().with_quote_mint(crate::constants::USDC_TOKEN_ACCOUNT);
         }
 
         let instructions = build_sell(&params).unwrap();

src/trading/common/transaction_builder.rs

@@ -46,7 +46,7 @@ pub fn build_transaction(
     tip_amount: f64,
     durable_nonce: Option<&DurableNonceInfo>,
 ) -> Result<VersionedTransaction, anyhow::Error> {
-    let transaction = build_transaction_with_compute_budget(
+    let transaction = build_transaction_inner(
         payer,
         unit_limit,
         unit_price,
@@ -63,44 +63,32 @@ pub fn build_transaction(
     )?;
 
     let serialized_len = bincode::serialized_size(&transaction)? as usize;
-    if serialized_len <= PACKET_DATA_SIZE
-        || durable_nonce.is_some()
-        || !with_tip
-        || tip_amount <= 0.0
-        || (unit_limit == 0 && unit_price == 0)
-    {
+    if crate::common::sdk_log::sdk_log_enabled() {
+        println!(
+            " [SDK][tx-size     ] {} {} serialized={} bytes, business_ix={}, nonce={}, tip={}, cu_limit={}, cu_price={}, alt={}",
+            protocol_name,
+            if is_buy { "buy" } else { "sell" },
+            serialized_len,
+            business_instructions.len(),
+            durable_nonce.is_some(),
+            with_tip && tip_amount > 0.0,
+            unit_limit,
+            unit_price,
+            address_lookup_table_account.is_some()
+        );
+    }
+    if serialized_len <= PACKET_DATA_SIZE {
         return Ok(transaction);
     }
 
-    let compact_transaction = build_transaction_with_compute_budget(
-        payer,
-        0,
-        0,
-        business_instructions,
-        address_lookup_table_account,
-        recent_blockhash,
-        middleware_manager,
-        protocol_name,
-        is_buy,
-        with_tip,
-        tip_account,
-        tip_amount,
-        durable_nonce,
-    )?;
-    let compact_len = bincode::serialized_size(&compact_transaction)? as usize;
-    if compact_len <= PACKET_DATA_SIZE {
-        return Ok(compact_transaction);
-    }
-
     Err(anyhow!(
-        "transaction too large: {} > {}; compact without compute budget is {} bytes. Use an address lookup table or pre-create token ATAs before submitting",
+        "transaction too large: {} > {}; SDK did not remove compute budget or relay tip because that changes transaction priority semantics. Use an address lookup table or pre-create token ATAs before submitting",
         serialized_len,
-        PACKET_DATA_SIZE,
-        compact_len
+        PACKET_DATA_SIZE
     ))
 }
 
-fn build_transaction_with_compute_budget(
+fn build_transaction_inner(
     payer: &Arc<Keypair>,
     unit_limit: u32,
     unit_price: u64,
@@ -181,3 +169,41 @@ fn build_versioned_transaction(
 
     Ok(tx)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use solana_sdk::instruction::AccountMeta;
+
+    fn oversized_instruction(account_count: usize, data_len: usize) -> Instruction {
+        let accounts =
+            (0..account_count).map(|_| AccountMeta::new(Pubkey::new_unique(), false)).collect();
+        Instruction { program_id: Pubkey::new_unique(), accounts, data: vec![7; data_len] }
+    }
+
+    #[test]
+    fn oversized_transaction_returns_error_without_dropping_priority_semantics() {
+        let payer = Arc::new(Keypair::new());
+        let business_instructions = vec![oversized_instruction(36, 700)];
+        let err = build_transaction(
+            &payer,
+            80_000,
+            100_000,
+            &business_instructions,
+            None,
+            Some(Hash::new_unique()),
+            None,
+            "test",
+            true,
+            true,
+            &Pubkey::new_unique(),
+            0.001,
+            None,
+        )
+        .unwrap_err()
+        .to_string();
+
+        assert!(err.contains("transaction too large"), "{err}");
+        assert!(err.contains("did not remove compute budget or relay tip"), "{err}");
+    }
+}

src/trading/core/params/pumpfun.rs

@@ -14,9 +14,10 @@ use std::sync::Arc;
 /// **Buy/sell**：`creator_vault` 及（若可得）**`tradeEvent` / CPI 日志中的 `creator`** 优先于陈旧的曲线快照；
 /// ix 组装与链下询价见 [`Self::effective_creator_for_trade`]、[`crate::instruction::utils::pumpfun::resolve_creator_vault_for_ix_with_fee_sharing`]。
 ///
-/// **V2 instructions**: The SDK selects the layout automatically from `quote_mint`.
-/// Leave `quote_mint` default, or pass the Solscan SOL sentinel (`SOL_TOKEN_ACCOUNT`), for
-/// legacy SOL layout. Pass `WSOL_TOKEN_ACCOUNT` for SOL V2, or USDC for USDC-paired coins.
+/// **Instruction layout**: The SDK selects the smallest valid layout automatically from
+/// `quote_mint`. Native SOL-paired coins use the legacy SOL layout when `quote_mint`
+/// is default, the Solscan SOL sentinel (`SOL_TOKEN_ACCOUNT`), or the WSOL sentinel
+/// (`WSOL_TOKEN_ACCOUNT`). Non-native quote mints such as USDC use V2.
 #[derive(Clone)]
 pub struct PumpFunParams {
     pub bonding_curve: Arc<BondingCurveAccount>,
@@ -41,8 +42,9 @@ pub struct PumpFunParams {
     /// Fee recipient for buy/sell account #2. Set from sol-parser-sdk (`tradeEvent.feeRecipient` / 同笔 create_v2+buy 回填的 `observed_fee_recipient`)；热路径不查 RPC。
     /// `Pubkey::default()` 时只能使用 SDK 静态 fallback，可能落后于主网 Global；交易热路径应优先传入 gRPC / parser 观测值。
     pub fee_recipient: Pubkey,
-    /// Quote mint layout selector. Default and `SOL_TOKEN_ACCOUNT` use legacy SOL layout.
-    /// `WSOL_TOKEN_ACCOUNT` selects SOL v2; USDC selects USDC v2.
+    /// Quote mint layout selector. Default, `SOL_TOKEN_ACCOUNT`, and `WSOL_TOKEN_ACCOUNT`
+    /// are native SOL-paired and use the smaller legacy SOL layout by default.
+    /// USDC and other non-native quote mints select V2.
     /// For USDC-paired coins, set to `EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v`.
     pub quote_mint: Pubkey,
 }
@@ -50,7 +52,10 @@ pub struct PumpFunParams {
 impl PumpFunParams {
     #[inline]
     fn quote_mint_for_layout(quote_mint: Pubkey) -> Pubkey {
-        if quote_mint == Pubkey::default() || quote_mint == crate::constants::SOL_TOKEN_ACCOUNT {
+        if quote_mint == Pubkey::default()
+            || quote_mint == crate::constants::SOL_TOKEN_ACCOUNT
+            || quote_mint == crate::constants::WSOL_TOKEN_ACCOUNT
+        {
             Pubkey::default()
         } else {
             BondingCurveAccount::normalize_quote_mint(quote_mint)
@@ -59,7 +64,10 @@ impl PumpFunParams {
 
     #[inline]
     fn quote_mint_for_rpc_return(quote_mint: Pubkey) -> Pubkey {
-        if quote_mint == Pubkey::default() || quote_mint == crate::constants::SOL_TOKEN_ACCOUNT {
+        if quote_mint == Pubkey::default()
+            || quote_mint == crate::constants::SOL_TOKEN_ACCOUNT
+            || quote_mint == crate::constants::WSOL_TOKEN_ACCOUNT
+        {
             crate::constants::SOL_TOKEN_ACCOUNT
         } else {
             BondingCurveAccount::normalize_quote_mint(quote_mint)
@@ -176,8 +184,8 @@ impl PumpFunParams {
     }
 
     /// Build PumpFun params from event/parser data. Pass `quote_mint` from the event:
-    /// `Pubkey::default()` / `SOL_TOKEN_ACCOUNT` for legacy SOL layout,
-    /// `WSOL_TOKEN_ACCOUNT` for SOL V2, and `USDC_TOKEN_ACCOUNT` for USDC V2.
+    /// `Pubkey::default()` / `SOL_TOKEN_ACCOUNT` / `WSOL_TOKEN_ACCOUNT` for native SOL
+    /// layout, and `USDC_TOKEN_ACCOUNT` or another non-native quote mint for V2.
     /// Also pass `is_cashback_coin` from the event so sells include the correct remaining accounts.
     ///
     /// `mayhem_mode`:
@@ -369,8 +377,9 @@ impl PumpFunParams {
     }
 
     /// Sets `quote_mint`. The instruction builder derives V1/V2 layout from this value.
-    /// For legacy SOL-paired coins, pass `SOL_TOKEN_ACCOUNT` or leave default.
-    /// Pass `WSOL_TOKEN_ACCOUNT` only when you intentionally want SOL v2 layout.
+    /// For native SOL-paired coins, pass `Pubkey::default()`, `SOL_TOKEN_ACCOUNT`, or
+    /// `WSOL_TOKEN_ACCOUNT`; all three select the smaller V1 layout unless buy/sell params
+    /// explicitly request WSOL settlement. Pass USDC or another non-native quote mint for V2.
     #[inline]
     pub fn with_quote_mint(mut self, quote_mint: Pubkey) -> Self {
         let effective_quote_mint = BondingCurveAccount::normalize_quote_mint(quote_mint);
@@ -419,6 +428,10 @@ mod tests {
             PumpFunParams::quote_mint_for_rpc_return(crate::constants::SOL_TOKEN_ACCOUNT),
             crate::constants::SOL_TOKEN_ACCOUNT
         );
+        assert_eq!(
+            PumpFunParams::quote_mint_for_rpc_return(crate::constants::WSOL_TOKEN_ACCOUNT),
+            crate::constants::SOL_TOKEN_ACCOUNT
+        );
     }
 
     #[test]
@@ -427,9 +440,22 @@ mod tests {
             PumpFunParams::quote_mint_for_rpc_return(crate::constants::USDC_TOKEN_ACCOUNT),
             crate::constants::USDC_TOKEN_ACCOUNT
         );
+    }
+
+    #[test]
+    fn quote_mint_for_layout_normalizes_native_sol_sentinels_to_default() {
+        assert_eq!(PumpFunParams::quote_mint_for_layout(Pubkey::default()), Pubkey::default());
         assert_eq!(
-            PumpFunParams::quote_mint_for_rpc_return(crate::constants::WSOL_TOKEN_ACCOUNT),
-            crate::constants::WSOL_TOKEN_ACCOUNT
+            PumpFunParams::quote_mint_for_layout(crate::constants::SOL_TOKEN_ACCOUNT),
+            Pubkey::default()
+        );
+        assert_eq!(
+            PumpFunParams::quote_mint_for_layout(crate::constants::WSOL_TOKEN_ACCOUNT),
+            Pubkey::default()
+        );
+        assert_eq!(
+            PumpFunParams::quote_mint_for_layout(crate::constants::USDC_TOKEN_ACCOUNT),
+            crate::constants::USDC_TOKEN_ACCOUNT
         );
     }
 }