apollo_consensus_orchestrator: wire SNIP-35 fee_proposal into build_proposal

Author: sirandreww-starkware

crates/apollo_consensus_orchestrator/src/build_proposal.rs

@@ -76,6 +76,10 @@ pub(crate) struct ProposalBuildArguments {
     pub override_l2_gas_price_fri: Option<u128>,
     pub min_l2_gas_price_per_height: Vec<PricePerHeight>,
     pub compare_retrospective_block_hash: bool,
+    /// SNIP-35: proposer's fee_proposal for this block.
+    pub fee_proposal: GasPrice,
+    /// SNIP-35: current fee_actual from the sliding window.
+    pub fee_actual: Option<GasPrice>,
 }
 
 type BuildProposalResult<T> = Result<T, BuildProposalError>;
@@ -176,7 +180,7 @@ async fn initiate_build(args: &mut ProposalBuildArguments) -> BuildProposalResul
         starknet_version: starknet_api::block::StarknetVersion::LATEST,
         // TODO(Asmaa): Put the real value once we have it.
         version_constant_commitment: Default::default(),
-        fee_proposal_fri: None,
+        fee_proposal_fri: Some(args.fee_proposal),
     };
 
     let retrospective_block_hash = wait_for_retrospective_block_hash(
@@ -319,7 +323,7 @@ async fn get_proposal_content(
                     info.l2_gas_used,
                     args.override_l2_gas_price_fri,
                     &args.min_l2_gas_price_per_height,
-                    None,
+                    args.fee_actual,
                 );
                 let fin_payload = ProposalFinPayload {
                     commitment_parts: CommitmentParts::from(&info),

crates/apollo_consensus_orchestrator/src/sequencer_consensus_context.rs

@@ -75,7 +75,7 @@ use tokio::task::JoinHandle;
 use tokio::time::sleep;
 use tokio_util::sync::CancellationToken;
 use tokio_util::task::AbortOnDropHandle;
-use tracing::{error, error_span, info, instrument, trace, warn, Instrument};
+use tracing::{debug, error, error_span, info, instrument, trace, warn, Instrument};
 
 use crate::build_proposal::{build_proposal, BuildProposalError, ProposalBuildArguments};
 use crate::cende::{
@@ -94,8 +94,19 @@ use crate::metrics::{
     record_validate_proposal_failure,
     register_metrics,
     CONSENSUS_L2_GAS_PRICE,
+    SNIP35_FEE_ACTUAL,
+    SNIP35_FEE_PROPOSAL,
+    SNIP35_FEE_TARGET,
+    SNIP35_STRK_USD_RATE,
+};
+use crate::snip35::{
+    compute_fee_actual,
+    compute_fee_proposal,
+    compute_fee_target,
+    FEE_PROPOSAL_MARGIN_PPT,
+    FEE_PROPOSAL_WINDOW_SIZE,
+    TARGET_ATTO_USD_PER_L2_GAS,
 };
-use crate::snip35::FEE_PROPOSAL_WINDOW_SIZE;
 use crate::utils::{
     convert_to_sn_api_block_info,
     make_gas_price_params,
@@ -398,6 +409,7 @@ impl SequencerConsensusContext {
             sequencer,
             timestamp: BlockTimestamp(init.timestamp),
             l1_da_mode: init.l1_da_mode,
+            fee_proposal_fri: init.fee_proposal_fri,
             // TODO(guy.f): Figure out where/if to get the values below from and fill them.
             ..Default::default()
         };
@@ -416,16 +428,59 @@ impl SequencerConsensusContext {
     /// Returns the next L2 gas price without mutating context. Used when building the fin and when
     /// updating at decision time.
     fn calculate_next_l2_gas_price(&self, height: BlockNumber, l2_gas_used: GasAmount) -> GasPrice {
+        let fee_actual = compute_fee_actual(&self.fee_proposals_window, height);
         calculate_next_l2_gas_price_for_fin(
             self.l2_gas_price,
             height,
             l2_gas_used,
             self.config.dynamic_config.override_l2_gas_price_fri,
             &self.config.dynamic_config.min_l2_gas_price_per_height,
-            None,
+            fee_actual,
         )
     }
 
+    /// SNIP-35 fee_proposal: clamp the oracle's `fee_target` to a margin around `fee_actual`.
+    /// When `fee_actual` is `None` (window incomplete), freeze at `l2_gas_price`; the validator
+    /// derives the same fallback so both sides agree.
+    async fn compute_snip35_fee_proposal(
+        &self,
+        fee_actual: Option<GasPrice>,
+        timestamp: u64,
+    ) -> GasPrice {
+        let Some(fee_actual) = fee_actual else {
+            warn!("fee_actual unavailable, freezing fee_proposal at l2_gas_price");
+            SNIP35_FEE_PROPOSAL.set_lossy(self.l2_gas_price.0);
+            return self.l2_gas_price;
+        };
+        SNIP35_FEE_ACTUAL.set_lossy(fee_actual.0);
+
+        let fee_target = match &self.deps.strk_to_usd_oracle {
+            Some(oracle) => match oracle.fetch_rate(timestamp).await {
+                Ok(rate) => {
+                    SNIP35_STRK_USD_RATE.set_lossy(rate);
+                    let target = compute_fee_target(TARGET_ATTO_USD_PER_L2_GAS, rate);
+                    match target {
+                        Some(t) => SNIP35_FEE_TARGET.set_lossy(t.0),
+                        None => warn!("STRK/USD oracle returned zero rate, freezing fee_proposal"),
+                    }
+                    target
+                }
+                Err(e) => {
+                    warn!("STRK/USD oracle error: {e:?}, freezing fee_proposal");
+                    None
+                }
+            },
+            None => {
+                debug!("No STRK/USD oracle configured, freezing fee_proposal");
+                None
+            }
+        };
+
+        let proposal = compute_fee_proposal(fee_target, fee_actual, FEE_PROPOSAL_MARGIN_PPT);
+        SNIP35_FEE_PROPOSAL.set_lossy(proposal.0);
+        proposal
+    }
+
     fn update_l2_gas_price(&mut self, height: BlockNumber, l2_gas_used: GasAmount) {
         self.l2_gas_price = self.calculate_next_l2_gas_price(height, l2_gas_used);
         let gas_price_u64 = u64::try_from(self.l2_gas_price.0).unwrap_or(u64::MAX);
@@ -656,6 +711,9 @@ impl ConsensusContext for SequencerConsensusContext {
             BehaviorMode::Echonet => true,
             BehaviorMode::Starknet => false,
         };
+        let fee_actual = compute_fee_actual(&self.fee_proposals_window, build_param.height);
+        let fee_proposal =
+            self.compute_snip35_fee_proposal(fee_actual, self.deps.clock.unix_now()).await;
         let round = build_param.round;
         let args = ProposalBuildArguments {
             deps: self.deps.clone(),
@@ -689,6 +747,8 @@ impl ConsensusContext for SequencerConsensusContext {
                 .config
                 .dynamic_config
                 .compare_retrospective_block_hash,
+            fee_proposal,
+            fee_actual,
         };
 
         let handle = tokio::spawn(

crates/apollo_consensus_orchestrator/src/sequencer_consensus_context_test.rs

@@ -27,7 +27,11 @@ use apollo_l1_gas_price_types::errors::{
     L1GasPriceClientError,
     L1GasPriceProviderError,
 };
-use apollo_l1_gas_price_types::{MockL1GasPriceProviderClient, PriceInfo};
+use apollo_l1_gas_price_types::{
+    MockExchangeRateOracleClientTrait,
+    MockL1GasPriceProviderClient,
+    PriceInfo,
+};
 use apollo_protobuf::consensus::{
     BuildParam,
     CommitmentParts,
@@ -89,6 +93,7 @@ fn expected_l2_gas_info_for_build_proposal_defaults() -> L2GasInfo {
         l2_gas_used: GasAmount(0),
     }
 }
+use crate::snip35::{compute_fee_actual, FEE_PROPOSAL_WINDOW_SIZE};
 use crate::utils::{apply_fee_transformations, make_gas_price_params};
 
 const TEST_PROPOSAL_COMMITMENT: ProposalCommitment = ProposalCommitment(PARTIAL_BLOCK_HASH.0);
@@ -1601,3 +1606,137 @@ async fn test_initialize_fee_proposals_window(
     context.initialize_fee_proposals_window(start_height).await.unwrap();
     assert_eq!(context.fee_proposals_window, expected_window);
 }
+
+#[derive(Clone)]
+enum OracleBehavior {
+    /// No oracle is configured (`strk_to_usd_oracle = None`).
+    NotConfigured,
+    /// Oracle is configured and `fetch_rate` returns `Ok(rate)`.
+    Ok(u128),
+    /// Oracle is configured and `fetch_rate` returns `Err(_)`.
+    Err,
+}
+
+// fee_actual = 10 gwei => margin bounds [9_980_039_920, 10_020_000_000].
+#[rstest]
+#[case::no_fee_actual_freezes_at_l2_gas_price(
+    None,
+    OracleBehavior::NotConfigured,
+    GasPrice(7_000_000_000),
+    GasPrice(7_000_000_000)
+)]
+#[case::no_oracle_freezes_at_fee_actual(
+    Some(GasPrice(10_000_000_000)),
+    OracleBehavior::NotConfigured,
+    GasPrice(7_000_000_000),
+    GasPrice(10_000_000_000)
+)]
+#[case::oracle_zero_rate_freezes_at_fee_actual(
+    Some(GasPrice(10_000_000_000)),
+    OracleBehavior::Ok(0),
+    GasPrice(7_000_000_000),
+    GasPrice(10_000_000_000)
+)]
+#[case::oracle_err_freezes_at_fee_actual(
+    Some(GasPrice(10_000_000_000)),
+    OracleBehavior::Err,
+    GasPrice(7_000_000_000),
+    GasPrice(10_000_000_000)
+)]
+#[case::oracle_target_in_bounds_returns_target(
+    Some(GasPrice(10_000_000_000)),
+    OracleBehavior::Ok(300_000_000_000_000_000),
+    GasPrice(7_000_000_000),
+    GasPrice(10_000_000_000)
+)]
+#[case::oracle_target_above_clamps_to_upper(
+    Some(GasPrice(10_000_000_000)),
+    OracleBehavior::Ok(1),
+    GasPrice(7_000_000_000),
+    GasPrice(10_020_000_000)
+)]
+#[case::oracle_target_below_clamps_to_lower(
+    Some(GasPrice(10_000_000_000)),
+    OracleBehavior::Ok(1_000_000_000_000_000_000_000),
+    GasPrice(7_000_000_000),
+    GasPrice(9_980_039_920)
+)]
+#[tokio::test]
+async fn test_compute_snip35_fee_proposal(
+    #[case] fee_actual: Option<GasPrice>,
+    #[case] oracle_behavior: OracleBehavior,
+    #[case] l2_gas_price: GasPrice,
+    #[case] expected_fee_proposal: GasPrice,
+) {
+    let (mut deps, _network) = create_test_and_network_deps();
+    deps.setup_default_expectations();
+    deps.strk_to_usd_oracle = match oracle_behavior {
+        OracleBehavior::NotConfigured => None,
+        OracleBehavior::Ok(rate) => {
+            let mut mock = MockExchangeRateOracleClientTrait::new();
+            mock.expect_fetch_rate().returning(move |_| Ok(rate));
+            Some(Arc::new(mock))
+        }
+        OracleBehavior::Err => {
+            let mut mock = MockExchangeRateOracleClientTrait::new();
+            mock.expect_fetch_rate().returning(|_| {
+                Err(ExchangeRateOracleClientError::RequestError("test".to_string()))
+            });
+            Some(Arc::new(mock))
+        }
+    };
+
+    let mut context = deps.build_context();
+    context.l2_gas_price = l2_gas_price;
+    let proposal = context.compute_snip35_fee_proposal(fee_actual, 0).await;
+    assert_eq!(proposal, expected_fee_proposal);
+}
+
+#[tokio::test]
+async fn test_compute_snip35_fee_proposal_converges_to_oracle_target() {
+    // (strk_usd_rate, fee_target, n_blocks_until_convergence_with_buffer).
+    // 75 gwei bootstrap -> 100 gwei target at +33% reaches by block ~795.
+    // 100 gwei -> 60 gwei at -40% reaches by block ~1410.
+    let phases: [(u128, GasPrice, u64); 2] = [
+        (30_000_000_000_000_000, GasPrice(100_000_000_000), 800),
+        (50_000_000_000_000_000, GasPrice(60_000_000_000), 1420),
+    ];
+
+    let (mut deps, _network) = create_test_and_network_deps();
+    deps.setup_default_expectations();
+    let mut mock = MockExchangeRateOracleClientTrait::new();
+    let mut seq = mockall::Sequence::new();
+    for &(rate, _, n_blocks) in &phases {
+        mock.expect_fetch_rate()
+            .times(usize::try_from(n_blocks).unwrap())
+            .in_sequence(&mut seq)
+            .returning(move |_| Ok(rate));
+    }
+    deps.strk_to_usd_oracle = Some(Arc::new(mock));
+    let mut context = deps.build_context();
+
+    // Bootstrap the window with 75 gwei (the $0.04 target).
+    let window_size = u64::try_from(FEE_PROPOSAL_WINDOW_SIZE).unwrap();
+    for h in 0..window_size {
+        context.record_fee_proposal(BlockNumber(h), Some(GasPrice(75_000_000_000)));
+    }
+
+    let mut height = window_size;
+    for (phase_idx, (_, fee_target, n_blocks)) in phases.into_iter().enumerate() {
+        for _ in 0..n_blocks {
+            let h = BlockNumber(height);
+            let fee_actual = compute_fee_actual(&context.fee_proposals_window, h)
+                .expect("window stays complete across the loop");
+            let proposal = context.compute_snip35_fee_proposal(Some(fee_actual), 0).await;
+            context.record_fee_proposal(h, Some(proposal));
+            height += 1;
+        }
+        let final_fee_actual =
+            compute_fee_actual(&context.fee_proposals_window, BlockNumber(height))
+                .expect("window stays complete across the loop");
+        assert_eq!(
+            final_fee_actual, fee_target,
+            "phase {phase_idx}: fee_actual did not reach fee_target after {n_blocks} blocks",
+        );
+    }
+}