Merge pull request #246 from chainbound/naman/feat/min-priority-fee

feat(sidecar): min priority fee

bolt-sidecar/src/common.rs

@@ -9,7 +9,7 @@ use crate::{
 /// The version of the Bolt sidecar binary.
 pub const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
 
-/// Calculates the max_basefee `slot_diff` blocks in the future given a current basefee (in gwei).
+/// Calculates the max_basefee `slot_diff` blocks in the future given a current basefee (in wei).
 /// Returns None if an overflow would occur.
 /// Cfr. https://github.com/flashbots/ethers-provider-flashbots-bundle/blob/7ddaf2c9d7662bef400151e0bfc89f5b13e72b4c/src/index.ts#L308
 pub fn calculate_max_basefee(current: u128, block_diff: u64) -> Option<u128> {

bolt-sidecar/src/config/mod.rs

@@ -28,6 +28,11 @@ pub const DEFAULT_RPC_PORT: u16 = 8000;
 /// Default port for the Constraints proxy server.
 pub const DEFAULT_CONSTRAINTS_PROXY_PORT: u16 = 18551;
 
+// Default limit values
+pub const DEFAULT_MAX_COMMITMENTS: usize = 128;
+pub const DEFAULT_MAX_COMMITTED_GAS: u64 = 10_000_000;
+pub const DEFAULT_MIN_PRIORITY_FEE: u128 = 1000000000; // 1 Gwei
+
 /// Command-line options for the Bolt sidecar
 #[derive(Parser, Debug)]
 pub struct Opts {
@@ -55,6 +60,9 @@ pub struct Opts {
     /// Max committed gas per slot
     #[clap(long, env = "BOLT_SIDECAR_MAX_COMMITTED_GAS")]
     pub(super) max_committed_gas: Option<NonZero<u64>>,
+    /// Min priority fee to accept for a commitment
+    #[clap(long, env = "BOLT_SIDECAR_MIN_PRIORITY_FEE")]
+    pub(super) min_priority_fee: Option<NonZero<u128>>,
     /// Validator indexes of connected validators that the sidecar
     /// should accept commitments on behalf of. Accepted values:
     /// - a comma-separated list of indexes (e.g. "1,2,3,4")
@@ -158,13 +166,19 @@ pub struct Limits {
     /// Maximum number of commitments to accept per block
     pub max_commitments_per_slot: NonZero<usize>,
     pub max_committed_gas_per_slot: NonZero<u64>,
+
+    /// Minimum priority fee to accept for a commitment in wei
+    pub min_priority_fee: NonZero<u128>,
 }
 
 impl Default for Limits {
     fn default() -> Self {
         Self {
-            max_commitments_per_slot: NonZero::new(128).expect("Valid non-zero"),
-            max_committed_gas_per_slot: NonZero::new(10_000_000).expect("Valid non-zero"),
+            max_commitments_per_slot: NonZero::new(DEFAULT_MAX_COMMITMENTS)
+                .expect("Valid non-zero"),
+            max_committed_gas_per_slot: NonZero::new(DEFAULT_MAX_COMMITTED_GAS)
+                .expect("Valid non-zero"),
+            min_priority_fee: NonZero::new(DEFAULT_MIN_PRIORITY_FEE).expect("Valid non-zero"),
         }
     }
 }
@@ -195,6 +209,10 @@ impl TryFrom<Opts> for Config {
             config.limits.max_committed_gas_per_slot = max_committed_gas;
         }
 
+        if let Some(min_priority_fee) = opts.min_priority_fee {
+            config.limits.min_priority_fee = min_priority_fee;
+        }
+
         if let Some(commit_boost_url) = &opts.signing.commit_boost_url {
             if let Ok(url) = Url::parse(commit_boost_url) {
                 if let Ok(socket_addrs) = url.socket_addrs(|| None) {

bolt-sidecar/src/primitives/commitment.rs

@@ -143,19 +143,28 @@ impl InclusionRequest {
         true
     }
 
-    pub fn validate_priority_fee(&self) -> bool {
+    /// Validates the priority fee against the max fee per gas.
+    /// Returns true if the fee is less than or equal to the max fee per gas, false otherwise.
+    /// Ref: https://github.com/paradigmxyz/reth/blob/2d592125128c3742ff97b321884f93f9063abcb2/crates/transaction-pool/src/validate/eth.rs#L242
+    pub fn validate_max_priority_fee(&self) -> bool {
         for tx in &self.txs {
-            if tx
-                .max_priority_fee_per_gas()
-                .is_some_and(|max_priority_fee| max_priority_fee > tx.max_fee_per_gas())
-            {
+            if tx.max_priority_fee_per_gas() > Some(tx.max_fee_per_gas()) {
                 return false;
             }
         }
 
         true
     }
 
+    /// Validates the priority fee against a minimum priority fee.
+    /// Returns `true` if the "effective priority fee" is greater than or equal to the set minimum
+    /// priority fee, `false` otherwise.
+    pub fn validate_min_priority_fee(&self, max_base_fee: u128, min_priority_fee: u128) -> bool {
+        self.txs.iter().all(|tx| {
+            tx.effective_tip_per_gas(max_base_fee).map_or(false, |tip| tip >= min_priority_fee)
+        })
+    }
+
     /// Returns the total gas limit of all transactions in this request.
     pub fn gas_limit(&self) -> u64 {
         self.txs.iter().map(|tx| tx.gas_limit()).sum()

bolt-sidecar/src/primitives/mod.rs

@@ -387,6 +387,29 @@ impl FullTransaction {
     pub fn sender(&self) -> Option<&Address> {
         self.sender.as_ref()
     }
+
+    /// Returns the effective miner gas tip cap (`gasTipCap`) for the given base fee:
+    /// `min(maxFeePerGas - baseFee, maxPriorityFeePerGas)`
+    ///
+    /// Returns `None` if the basefee is higher than the [`Transaction::max_fee_per_gas`].
+    /// Ref: https://github.com/paradigmxyz/reth/blob/2d592125128c3742ff97b321884f93f9063abcb2/crates/primitives/src/transaction/mod.rs#L444
+    pub fn effective_tip_per_gas(&self, base_fee: u128) -> Option<u128> {
+        let max_fee_per_gas = self.max_fee_per_gas();
+
+        if max_fee_per_gas < base_fee {
+            return None;
+        }
+
+        // Calculate the difference between max_fee_per_gas and base_fee
+        let fee = max_fee_per_gas - base_fee;
+
+        // Compare the fee with max_priority_fee_per_gas (or gas price for non-EIP1559 transactions)
+        if let Some(priority_fee) = self.max_priority_fee_per_gas() {
+            Some(fee.min(priority_fee))
+        } else {
+            Some(fee)
+        }
+    }
 }
 
 fn serialize_txs<S: serde::Serializer>(
@@ -438,8 +461,8 @@ pub struct DelegationMessage {
 impl SignableBLS for DelegationMessage {
     fn digest(&self) -> [u8; 32] {
         let mut hasher = Sha256::new();
-        hasher.update(&self.validator_pubkey.to_vec());
-        hasher.update(&self.delegatee_pubkey.to_vec());
+        hasher.update(self.validator_pubkey.to_vec());
+        hasher.update(self.delegatee_pubkey.to_vec());
 
         hasher.finalize().into()
     }
@@ -460,8 +483,8 @@ pub struct RevocationMessage {
 impl SignableBLS for RevocationMessage {
     fn digest(&self) -> [u8; 32] {
         let mut hasher = Sha256::new();
-        hasher.update(&self.validator_pubkey.to_vec());
-        hasher.update(&self.delegatee_pubkey.to_vec());
+        hasher.update(self.validator_pubkey.to_vec());
+        hasher.update(self.delegatee_pubkey.to_vec());
 
         hasher.finalize().into()
     }

bolt-sidecar/src/state/execution.rs

@@ -21,8 +21,7 @@ use super::fetcher::StateFetcher;
 
 /// Possible commitment validation errors.
 ///
-/// NOTE: unfortuntately it cannot implement `Clone` due to `BlobTransactionValidationError`
-/// not implementing it
+/// NOTE: `Clone` not implementable due to `BlobTransactionValidationError`
 #[derive(Debug, Error)]
 pub enum ValidationError {
     /// The transaction fee is too low to cover the maximum base fee.
@@ -55,6 +54,9 @@ pub enum ValidationError {
     /// Max priority fee per gas is greater than max fee per gas.
     #[error("Max priority fee per gas is greater than max fee per gas")]
     MaxPriorityFeePerGasTooHigh,
+    /// Max priority fee per gas is less than min priority fee.
+    #[error("Max priority fee per gas is less than min priority fee")]
+    MaxPriorityFeePerGasTooLow,
     /// The sender does not have enough balance to pay for the transaction.
     #[error("Not enough balance to pay for value + maximum fee")]
     InsufficientBalance,
@@ -103,6 +105,7 @@ impl ValidationError {
             ValidationError::GasLimitTooHigh => "gas_limit_too_high",
             ValidationError::TransactionSizeTooHigh => "transaction_size_too_high",
             ValidationError::MaxPriorityFeePerGasTooHigh => "max_priority_fee_per_gas_too_high",
+            ValidationError::MaxPriorityFeePerGasTooLow => "max_priority_fee_per_gas_too_low",
             ValidationError::InsufficientBalance => "insufficient_balance",
             ValidationError::Eip4844Limit => "eip4844_limit",
             ValidationError::SlotTooLow(_) => "slot_too_low",
@@ -277,7 +280,7 @@ impl<C: StateFetcher> ExecutionState<C> {
         }
 
         // Ensure max_priority_fee_per_gas is less than max_fee_per_gas
-        if !req.validate_priority_fee() {
+        if !req.validate_max_priority_fee() {
             return Err(ValidationError::MaxPriorityFeePerGasTooHigh);
         }
 
@@ -295,6 +298,11 @@ impl<C: StateFetcher> ExecutionState<C> {
             return Err(ValidationError::BaseFeeTooLow(max_basefee));
         }
 
+        // Ensure max_priority_fee_per_gas is greater than or equal to min_priority_fee
+        if !req.validate_min_priority_fee(max_basefee, self.limits.min_priority_fee.get()) {
+            return Err(ValidationError::MaxPriorityFeePerGasTooLow);
+        }
+
         if target_slot < self.slot {
             debug!(%target_slot, %self.slot, "Target slot lower than current slot");
             return Err(ValidationError::SlotTooLow(self.slot));
@@ -523,14 +531,16 @@ mod tests {
     use std::{num::NonZero, str::FromStr, time::Duration};
 
     use alloy::{
-        consensus::constants::ETH_TO_WEI,
+        consensus::constants::{ETH_TO_WEI, LEGACY_TX_TYPE_ID},
         eips::eip2718::Encodable2718,
         network::EthereumWallet,
         primitives::{uint, Uint},
         providers::{network::TransactionBuilder, Provider, ProviderBuilder},
         signers::local::PrivateKeySigner,
     };
     use fetcher::{StateClient, StateFetcher};
+    use reth_primitives::constants::GWEI_TO_WEI;
+    use tracing::info;
 
     use crate::{
         crypto::{bls::Signer, SignableBLS, SignerBLS},
@@ -752,7 +762,13 @@ mod tests {
         let anvil = launch_anvil();
         let client = StateClient::new(anvil.endpoint_url());
 
-        let mut state = ExecutionState::new(client.clone(), Limits::default()).await?;
+        let limits = Limits {
+            max_commitments_per_slot: NonZero::new(10).unwrap(),
+            max_committed_gas_per_slot: NonZero::new(5_000_000).unwrap(),
+            min_priority_fee: NonZero::new(200000000).unwrap(), // 0.2 gwei
+        };
+
+        let mut state = ExecutionState::new(client.clone(), limits).await?;
 
         let basefee = state.basefee();
 
@@ -785,9 +801,10 @@ mod tests {
         let anvil = launch_anvil();
         let client = StateClient::new(anvil.endpoint_url());
 
-        let limits: Limits = Limits {
+        let limits = Limits {
             max_commitments_per_slot: NonZero::new(10).unwrap(),
             max_committed_gas_per_slot: NonZero::new(5_000_000).unwrap(),
+            min_priority_fee: NonZero::new(2000000000).unwrap(),
         };
         let mut state = ExecutionState::new(client.clone(), limits).await?;
 
@@ -810,6 +827,95 @@ mod tests {
         Ok(())
     }
 
+    #[tokio::test]
+    async fn test_invalid_inclusion_request_min_priority_fee() -> eyre::Result<()> {
+        let anvil = launch_anvil();
+        let client = StateClient::new(anvil.endpoint_url());
+
+        let limits = Limits {
+            max_commitments_per_slot: NonZero::new(10).unwrap(),
+            max_committed_gas_per_slot: NonZero::new(5_000_000).unwrap(),
+            min_priority_fee: NonZero::new(2 * GWEI_TO_WEI as u128).unwrap(),
+        };
+
+        let mut state = ExecutionState::new(client.clone(), limits).await?;
+
+        let sender = anvil.addresses().first().unwrap();
+        let sender_pk = anvil.keys().first().unwrap();
+
+        // initialize the state by updating the head once
+        let slot = client.get_head().await?;
+        state.update_head(None, slot).await?;
+
+        // Create a transaction with a max priority fee that is too low
+        let tx = default_test_transaction(*sender, None)
+            .with_max_priority_fee_per_gas(GWEI_TO_WEI as u128);
+
+        let mut request = create_signed_commitment_request(&[tx], sender_pk, 10).await?;
+
+        assert!(matches!(
+            state.validate_request(&mut request).await,
+            Err(ValidationError::MaxPriorityFeePerGasTooLow)
+        ));
+
+        // Create a transaction with a max priority fee that is correct
+        let tx = default_test_transaction(*sender, None)
+            .with_max_priority_fee_per_gas(3 * GWEI_TO_WEI as u128);
+
+        let mut request = create_signed_commitment_request(&[tx], sender_pk, 10).await?;
+
+        assert!(state.validate_request(&mut request).await.is_ok());
+
+        Ok(())
+    }
+
+    #[tokio::test]
+    async fn test_invalid_inclusion_request_min_priority_fee_legacy() -> eyre::Result<()> {
+        let anvil = launch_anvil();
+        let client = StateClient::new(anvil.endpoint_url());
+
+        let limits = Limits {
+            max_commitments_per_slot: NonZero::new(10).unwrap(),
+            max_committed_gas_per_slot: NonZero::new(5_000_000).unwrap(),
+            min_priority_fee: NonZero::new(2 * GWEI_TO_WEI as u128).unwrap(),
+        };
+
+        let mut state = ExecutionState::new(client.clone(), limits).await?;
+
+        let sender = anvil.addresses().first().unwrap();
+        let sender_pk = anvil.keys().first().unwrap();
+
+        // initialize the state by updating the head once
+        let slot = client.get_head().await?;
+        state.update_head(None, slot).await?;
+
+        let base_fee = state.basefee();
+        let Some(max_base_fee) = calculate_max_basefee(base_fee, 10 - slot) else {
+            return Err(eyre::eyre!("Failed to calculate max base fee"));
+        };
+
+        // Create a transaction with a gas price that is too low
+        let tx = default_test_transaction(*sender, None)
+            .with_gas_price(max_base_fee + GWEI_TO_WEI as u128);
+
+        let mut request = create_signed_commitment_request(&[tx], sender_pk, 10).await?;
+
+        assert!(matches!(
+            state.validate_request(&mut request).await,
+            Err(ValidationError::MaxPriorityFeePerGasTooLow)
+        ));
+
+        // Create a transaction with a gas price that is correct
+        let tx = default_test_transaction(*sender, None)
+            .with_gas_price(max_base_fee + 3 * GWEI_TO_WEI as u128);
+
+        let mut request = create_signed_commitment_request(&[tx], sender_pk, 10).await?;
+
+        assert!(state.validate_request(&mut request).await.is_ok());
+
+        Ok(())
+    }
+
     #[tokio::test]
     async fn test_invalidate_inclusion_request() -> eyre::Result<()> {
         let _ = tracing_subscriber::fmt::try_init();
@@ -916,6 +1022,7 @@ mod tests {
         let limits: Limits = Limits {
             max_commitments_per_slot: NonZero::new(10).unwrap(),
             max_committed_gas_per_slot: NonZero::new(5_000_000).unwrap(),
+            min_priority_fee: NonZero::new(1000000000).unwrap(),
         };
         let mut state = ExecutionState::new(client.clone(), limits).await?;
 

bolt-sidecar/src/test_util.rs

@@ -112,7 +112,7 @@ pub(crate) fn default_test_transaction(sender: Address, nonce: Option<u64>) -> T
         .with_nonce(nonce.unwrap_or(0))
         .with_value(U256::from(100))
         .with_gas_limit(21_000)
-        .with_max_priority_fee_per_gas(1_000_000_000)
+        .with_max_priority_fee_per_gas(1_000_000_000) // 1 gwei
         .with_max_fee_per_gas(20_000_000_000)
 }
 
@@ -189,7 +189,7 @@ fn random_constraints(count: usize) -> Vec<FullTransaction> {
 
     let req: InclusionRequest = serde_json::from_str(json_req).unwrap();
 
-    req.txs.iter().cloned().take(count).collect()
+    req.txs.iter().take(count).cloned().collect()
 }
 
 #[tokio::test]