feat: Add ppm precision to swap v2 fees

Barnabas Ratki · Barnabas Ratki · commit 871986672197 · 2025-04-04T16:37:21.000+02:00
diff --git a/contracts/svm/programs/express_relay/src/lib.rs b/contracts/svm/programs/express_relay/src/lib.rs
@@ -182,8 +182,8 @@ pub mod express_relay {
         )
     }
 
-
     pub fn swap_internal(ctx: Context<Swap>, data: SwapV2Args) -> Result<()> {
+        ctx.accounts.check_raw_constraints(data.fee_token)?;
         check_deadline(data.deadline)?;
         ctx.accounts
             .express_relay_metadata
@@ -227,6 +227,7 @@ pub mod express_relay {
 
         Ok(())
     }
+
     pub fn swap(ctx: Context<Swap>, data: SwapArgs) -> Result<()> {
         let data = ctx.accounts.convert_to_v2(&data);
         swap_internal(ctx, data)
@@ -438,31 +439,31 @@ pub struct SwapArgs {
 impl SwapArgs {
     pub fn convert_to_v2(&self, swap_platform_fee_bps: u64) -> SwapV2Args {
         SwapV2Args {
-            deadline: self.deadline,
-            amount_searcher: self.amount_searcher,
-            amount_user: self.amount_user,
-            fee_token: self.fee_token,
-            referral_fee_bps: self.referral_fee_bps,
-            swap_platform_fee_bps,
+            deadline:              self.deadline,
+            amount_searcher:       self.amount_searcher,
+            amount_user:           self.amount_user,
+            fee_token:             self.fee_token,
+            referral_fee_ppm:      u64::from(self.referral_fee_bps) * FEE_BPS_TO_PPM,
+            swap_platform_fee_ppm: swap_platform_fee_bps * FEE_BPS_TO_PPM,
         }
     }
 }
 
 #[derive(AnchorSerialize, AnchorDeserialize, Eq, PartialEq, Clone, Copy, Debug)]
 pub struct SwapV2Args {
-    // deadline as a unix timestamp in seconds
+    /// deadline as a unix timestamp in seconds
     pub deadline:              i64,
     pub amount_searcher:       u64,
     pub amount_user:           u64,
-    // The referral fee is specified in basis points
-    pub referral_fee_bps:      u16,
-    // Token in which the fees will be paid
+    /// The referral fee is specified in mill percentile
+    pub referral_fee_ppm:      u64,
+    /// Token in which the fees will be paid
     pub fee_token:             FeeToken,
-    pub swap_platform_fee_bps: u64,
+    /// The platform fee is specified in mill percentile
+    pub swap_platform_fee_ppm: u64,
 }
 
 #[derive(Accounts)]
-#[instruction(data: Box<SwapArgs>)]
 pub struct Swap<'info> {
     /// Searcher is the party that fulfills the quote request
     pub searcher: Signer<'info>,
@@ -523,21 +524,19 @@ pub struct Swap<'info> {
     pub mint_searcher: Box<InterfaceAccount<'info, Mint>>,
 
     #[account(mint::token_program = token_program_user)]
+    /// CHECK: we check that this is set correctly based on the fee token manually since the V2 arguments are incompatible on the wire
     pub mint_user: Box<InterfaceAccount<'info, Mint>>,
 
     #[account(
         mint::token_program = token_program_fee,
-        constraint = mint_fee.key() == if data.fee_token == FeeToken::Searcher { mint_searcher.key() } else { mint_user.key() }
     )]
     pub mint_fee: Box<InterfaceAccount<'info, Mint>>,
 
     // Token programs
     pub token_program_searcher: Interface<'info, TokenInterface>,
     pub token_program_user:     Interface<'info, TokenInterface>,
 
-    #[account(
-        constraint = token_program_fee.key() == if data.fee_token == FeeToken::Searcher { token_program_searcher.key() } else { token_program_user.key() }
-    )]
+    /// CHECK: we check that this is set correctly based on the fee token manually since the V2 arguments are incompatible on the wire
     pub token_program_fee: Interface<'info, TokenInterface>,
 
     /// Express relay configuration
diff --git a/contracts/svm/programs/express_relay/src/state.rs b/contracts/svm/programs/express_relay/src/state.rs
@@ -2,6 +2,9 @@ use anchor_lang::prelude::*;
 
 pub const FEE_SPLIT_PRECISION: u64 = 10_000;
 
+pub const FEE_SPLIT_PRECISION_PPM: u64 = 100_000_000;
+pub const FEE_BPS_TO_PPM: u64 = 10_000;
+
 pub const RESERVE_EXPRESS_RELAY_METADATA: usize = 8 + 152 + 260;
 pub const SEED_METADATA: &[u8] = b"metadata";
 
diff --git a/contracts/svm/programs/express_relay/src/swap.rs b/contracts/svm/programs/express_relay/src/swap.rs
@@ -1,7 +1,11 @@
 use {
     crate::{
         error::ErrorCode,
-        state::ExpressRelayMetadata,
+        state::{
+            ExpressRelayMetadata,
+            FEE_BPS_TO_PPM,
+            FEE_SPLIT_PRECISION_PPM,
+        },
         token::check_receiver_and_transfer_token_if_needed,
         FeeToken,
         Swap,
@@ -23,10 +27,46 @@ pub struct PostFeeSwapArgs {
 }
 
 
-impl<'info> Swap<'info> {
+impl Swap<'_> {
     pub fn convert_to_v2(&self, args: &SwapArgs) -> SwapV2Args {
         args.convert_to_v2(self.express_relay_metadata.swap_platform_fee_bps)
     }
+}
+
+impl<'info> Swap<'info> {
+    fn check_mint_user(&self, fee_token: FeeToken) -> Result<()> {
+        let correct_mint_fee_key = if fee_token == FeeToken::Searcher {
+            self.mint_searcher.key()
+        } else {
+            self.mint_user.key()
+        };
+
+        // Preserve API compatibility by returning the same error as the anchor validator did
+        (self.mint_fee.key() == correct_mint_fee_key)
+            .then_some(())
+            .ok_or(AnchorErrorCode::ConstraintRaw.into())
+    }
+
+    fn check_token_program_fee(&self, fee_token: FeeToken) -> Result<()> {
+        let correct_token_program_fee = if fee_token == FeeToken::Searcher {
+            self.token_program_searcher.key()
+        } else {
+            self.token_program_user.key()
+        };
+
+        // Preserve API compatibility by returning the same error as the anchor validator did
+        (self.token_program_fee.key() == correct_token_program_fee)
+            .then_some(())
+            .ok_or(AnchorErrorCode::ConstraintRaw.into())
+    }
+
+    pub fn check_raw_constraints(&self, fee_token: FeeToken) -> Result<()> {
+        self.check_mint_user(fee_token)?;
+        self.check_token_program_fee(fee_token)?;
+
+        Ok(())
+    }
+
     pub fn compute_swap_fees<'a>(
         &'a self,
         args: &SwapV2Args,
@@ -37,8 +77,8 @@ impl<'info> Swap<'info> {
                     fees,
                     remaining_amount,
                 } = self.express_relay_metadata.compute_swap_fees(
-                    args.referral_fee_bps,
-                    args.swap_platform_fee_bps,
+                    args.referral_fee_ppm,
+                    args.swap_platform_fee_ppm,
                     args.amount_searcher,
                 )?;
                 Ok((
@@ -58,8 +98,8 @@ impl<'info> Swap<'info> {
                     fees,
                     remaining_amount,
                 } = self.express_relay_metadata.compute_swap_fees(
-                    args.referral_fee_bps,
-                    args.swap_platform_fee_bps,
+                    args.referral_fee_ppm,
+                    args.swap_platform_fee_ppm,
                     args.amount_user,
                 )?;
                 Ok((
@@ -165,25 +205,28 @@ impl ExpressRelayMetadata {
         referral_fee_bps: u16,
         amount: u64,
     ) -> Result<SwapFeesWithRemainingAmount> {
-        self.compute_swap_fees(referral_fee_bps, self.swap_platform_fee_bps, amount)
+        let referral_fee_ppms = u64::from(referral_fee_bps) * FEE_BPS_TO_PPM;
+        let swap_platform_fees_ppms = self.swap_platform_fee_bps * FEE_BPS_TO_PPM;
+
+        self.compute_swap_fees(referral_fee_ppms, swap_platform_fees_ppms, amount)
     }
     pub fn compute_swap_fees(
         &self,
-        referral_fee_bps: u16,
-        swap_platform_fee_bps: u64,
+        referral_fee_ppm: u64,
+        swap_platform_fee_ppm: u64,
         amount: u64,
     ) -> Result<SwapFeesWithRemainingAmount> {
-        if u64::from(referral_fee_bps) > FEE_SPLIT_PRECISION {
+        if referral_fee_ppm > FEE_SPLIT_PRECISION_PPM {
             return Err(ErrorCode::InvalidReferralFee.into());
         }
         let router_fee = amount
-            .checked_mul(referral_fee_bps.into())
+            .checked_mul(referral_fee_ppm)
             .ok_or(ProgramError::ArithmeticOverflow)?
-            / FEE_SPLIT_PRECISION;
+            / FEE_SPLIT_PRECISION_PPM;
         let platform_fee = amount
-            .checked_mul(swap_platform_fee_bps)
+            .checked_mul(swap_platform_fee_ppm)
             .ok_or(ProgramError::ArithmeticOverflow)?
-            / FEE_SPLIT_PRECISION;
+            / FEE_SPLIT_PRECISION_PPM;
         let relayer_fee = platform_fee
             .checked_mul(self.split_relayer)
             .ok_or(ProgramError::ArithmeticOverflow)?
diff --git a/contracts/svm/testing/src/express_relay/swap.rs b/contracts/svm/testing/src/express_relay/swap.rs
@@ -19,6 +19,7 @@ use {
         },
         FeeToken,
         SwapArgs,
+        SwapV2Args,
     },
     solana_sdk::{
         instruction::Instruction,
@@ -34,25 +35,50 @@ pub struct SwapParamOverride {
     pub searcher_ta_mint_user:          Option<Pubkey>,
     pub express_relay_fee_receiver_ata: Option<Pubkey>,
     pub relayer_fee_receiver_ata:       Option<Pubkey>,
-    pub platform_fee_bps:               Option<u64>,
 }
 
-pub struct SwapParams {
+pub trait AnyVersionSwapArgs: Sized + Send + Sync {
+    fn get_fee_token(&self) -> FeeToken;
+
+    fn into_swap_instruction_data(self) -> Vec<u8>;
+}
+
+impl AnyVersionSwapArgs for SwapArgs {
+    fn get_fee_token(&self) -> FeeToken {
+        self.fee_token
+    }
+
+    fn into_swap_instruction_data(self) -> Vec<u8> {
+        Swap { data: self }.data()
+    }
+}
+
+impl AnyVersionSwapArgs for SwapV2Args {
+    fn get_fee_token(&self) -> FeeToken {
+        self.fee_token
+    }
+
+    fn into_swap_instruction_data(self) -> Vec<u8> {
+        SwapV2 { data: self }.data()
+    }
+}
+
+pub struct SwapParams<Args: AnyVersionSwapArgs = SwapArgs> {
     pub searcher:               Pubkey,
     pub user:                   Pubkey,
     pub router_fee_receiver_ta: Pubkey,
     pub fee_receiver_relayer:   Pubkey,
     pub token_searcher:         Token,
     pub token_user:             Token,
-    pub swap_args:              SwapArgs,
+    pub swap_args:              Args,
     pub relayer_signer:         Pubkey,
     /// Overrides from default behavior that may result in an invalid instruction
     /// and are meant to be used for testing.
     pub overrides:              SwapParamOverride,
 }
 
 /// Builds a swap instruction.
-pub fn create_swap_instruction(swap_params: SwapParams) -> Instruction {
+pub fn create_swap_instruction(swap_params: SwapParams<impl AnyVersionSwapArgs>) -> Instruction {
     let SwapParams {
         searcher,
         user,
@@ -70,20 +96,19 @@ pub fn create_swap_instruction(swap_params: SwapParams) -> Instruction {
                 mint_fee: mint_fee_override,
                 express_relay_fee_receiver_ata,
                 relayer_fee_receiver_ata,
-                platform_fee_bps,
             },
     } = swap_params;
     let express_relay_metadata = get_express_relay_metadata_key();
 
-    let mint_fee = mint_fee_override.unwrap_or(match swap_args.fee_token {
+    let mint_fee = mint_fee_override.unwrap_or(match swap_args.get_fee_token() {
         FeeToken::Searcher => token_searcher.mint,
         FeeToken::User => token_user.mint,
     });
 
     let token_program_searcher = token_searcher.token_program;
     let token_program_user = token_user.token_program;
 
-    let token_program_fee = match swap_args.fee_token {
+    let token_program_fee = match swap_args.get_fee_token() {
         FeeToken::Searcher => token_program_searcher,
         FeeToken::User => token_program_user,
     };
@@ -142,13 +167,7 @@ pub fn create_swap_instruction(swap_params: SwapParams) -> Instruction {
     }
     .to_account_metas(None);
 
-    let data = match platform_fee_bps {
-        Some(fee) => SwapV2 {
-            data: swap_args.convert_to_v2(fee),
-        }
-        .data(),
-        None => Swap { data: swap_args }.data(),
-    };
+    let data = swap_args.into_swap_instruction_data();
     Instruction {
         program_id: express_relay::ID,
         accounts: accounts_submit_bid,
@@ -157,7 +176,9 @@ pub fn create_swap_instruction(swap_params: SwapParams) -> Instruction {
 }
 
 /// Builds a set of instructions to perform a swap, including creating the associated token accounts.
-pub fn build_swap_instructions(swap_params: SwapParams) -> Vec<Instruction> {
+pub fn build_swap_instructions(
+    swap_params: SwapParams<impl AnyVersionSwapArgs>,
+) -> Vec<Instruction> {
     let SwapParams {
         searcher,
         user,
@@ -177,11 +198,11 @@ pub fn build_swap_instructions(swap_params: SwapParams) -> Vec<Instruction> {
 
     let token_program_searcher = token_searcher.token_program;
     let token_program_user = token_user.token_program;
-    let mint_fee = mint_fee_override.unwrap_or(match swap_args.fee_token {
+    let mint_fee = mint_fee_override.unwrap_or(match swap_args.get_fee_token() {
         FeeToken::Searcher => token_searcher.mint,
         FeeToken::User => token_user.mint,
     });
-    let token_program_fee = match swap_args.fee_token {
+    let token_program_fee = match swap_args.get_fee_token() {
         FeeToken::Searcher => token_program_searcher,
         FeeToken::User => token_program_user,
     };
diff --git a/contracts/svm/testing/src/token.rs b/contracts/svm/testing/src/token.rs
diff --git a/contracts/svm/testing/tests/swap.rs b/contracts/svm/testing/tests/swap.rs
