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 = 2;
+
 /// 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 gwei
+    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

@@ -1,7 +1,10 @@
 use serde::{de, Deserialize, Deserializer, Serialize};
 use std::str::FromStr;
 
-use alloy::primitives::{keccak256, Address, Signature, B256};
+use alloy::{
+    consensus::constants::GWEI_TO_WEI,
+    primitives::{keccak256, Address, Signature, B256},
+};
 
 use crate::{
     crypto::SignerECDSA,
@@ -143,12 +146,34 @@ 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.
+    pub fn validate_max_priority_fee(&self) -> bool {
+        for tx in &self.txs {
+            let gas_price = tx.as_legacy().map(|tx| tx.gas_price).unwrap_or(0);
+            let max_priority_fee = tx.max_priority_fee_per_gas().unwrap_or(0);
+            if max_priority_fee + gas_price > tx.max_fee_per_gas() {
+                return false;
+            }
+        }
+
+        true
+    }
+
+    /// Validates the priority fee against a minimum priority fee.
+    /// Returns true if the fee is greater than or equal to the set min priority fee, false
+    /// otherwise.
+    pub fn validate_min_priority_fee(&self, max_base_fee: u128, min_priority_fee: u128) -> 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())
-            {
+            let gas_price = tx.as_legacy().map(|tx| tx.gas_price).unwrap_or(0);
+            let gas_price = if max_base_fee >= gas_price {
+                0
+            } else {
+                (gas_price - max_base_fee) / GWEI_TO_WEI as u128
+            };
+            let max_priority_fee = tx.max_priority_fee_per_gas().unwrap_or(0);
+
+            if gas_price + max_priority_fee < min_priority_fee {
                 return false;
             }
         }

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);
         }
 
@@ -288,6 +291,11 @@ impl<C: StateFetcher> ExecutionState<C> {
         let max_basefee = calculate_max_basefee(self.basefee, slot_diff)
             .ok_or(ValidationError::MaxBaseFeeCalcOverflow)?;
 
+        // 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);
+        }
+
         debug!(%slot_diff, basefee = self.basefee, %max_basefee, "Validating basefee");
 
         // Validate the base fee
@@ -523,14 +531,15 @@ 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 tracing::info;
 
     use crate::{
         crypto::{bls::Signer, SignableBLS, SignerBLS},
@@ -785,9 +794,10 @@ 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(2).unwrap(),
         };
         let mut state = ExecutionState::new(client.clone(), limits).await?;
 
@@ -810,6 +820,82 @@ mod tests {
         Ok(())
     }
 
+    #[tokio::test]
+    async fn test_invalid_inclusion_request_legacy_tx() -> eyre::Result<()> {
+        let _ = tracing_subscriber::fmt::try_init();
+
+        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(10).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 legacy transaction with a max priority fee that is too low
+        let tx = default_test_transaction(*sender, None)
+            .transaction_type(LEGACY_TX_TYPE_ID)
+            .with_gas_price(10000000000); // Value is in wei = 10 gwei
+
+        info!(?tx, "Transaction");
+
+        let mut request = create_signed_commitment_request(&[tx], sender_pk, 10).await?;
+
+        // The request fails because the max base fee is also taken into account which decreases the
+        // final sum less than the min priority fee
+        assert!(matches!(
+            state.validate_request(&mut request).await,
+            Err(ValidationError::MaxPriorityFeePerGasTooLow)
+        ));
+
+        Ok(())
+    }
+
+    #[tokio::test]
+    async fn test_invalid_inclusion_request_min_priority_fee() -> eyre::Result<()> {
+        let _ = tracing_subscriber::fmt::try_init();
+
+        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(10).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(5);
+
+        let mut request = create_signed_commitment_request(&[tx], sender_pk, 10).await?;
+
+        assert!(matches!(
+            state.validate_request(&mut request).await,
+            Err(ValidationError::MaxPriorityFeePerGasTooLow)
+        ));
+
+        Ok(())
+    }
+
     #[tokio::test]
     async fn test_invalidate_inclusion_request() -> eyre::Result<()> {
         let _ = tracing_subscriber::fmt::try_init();
@@ -916,6 +1002,7 @@ 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(2).unwrap(),
         };
         let mut state = ExecutionState::new(client.clone(), limits).await?;