From 6daa1c1747ff01e3439334ae48679286e88f6d37 Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Wed, 14 Jan 2026 13:15:12 -0500
Subject: [PATCH 1/9] spike

---
 Cargo.lock                               |  1 +
 bin/node/src/cli.rs                      |  6 ++++
 crates/client/txpool/Cargo.toml          |  1 +
 crates/client/txpool/src/events.rs       |  3 ++
 crates/client/txpool/src/extension.rs    | 18 +++++++++++-
 crates/client/txpool/src/metrics.rs      |  5 ++++
 crates/client/txpool/src/subscription.rs | 24 ++++++++++++++--
 crates/client/txpool/src/tracker.rs      | 35 ++++++++++++++++++++++++
 8 files changed, 90 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index f2e2f8b1..1e30b121 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2138,6 +2138,7 @@ version = "0.0.0"
 dependencies = [
  "alloy-primitives",
  "base-client-node",
+ "base-flashblocks",
  "chrono",
  "derive_more",
  "eyre",
diff --git a/bin/node/src/cli.rs b/bin/node/src/cli.rs
index 03177da5..fb3588c9 100644
--- a/bin/node/src/cli.rs
+++ b/bin/node/src/cli.rs
@@ -56,10 +56,16 @@ impl From<Args> for Option<FlashblocksConfig> {
 
 impl From<Args> for TxpoolConfig {
     fn from(args: Args) -> Self {
+        let flashblocks_config = args
+            .websocket_url
+            .as_ref()
+            .map(|url| FlashblocksConfig::new(url.clone(), args.max_pending_blocks_depth));
+
         Self {
             tracing_enabled: args.enable_transaction_tracing,
             tracing_logs_enabled: args.enable_transaction_tracing_logs,
             sequencer_rpc: args.rollup_args.sequencer,
+            flashblocks_config,
         }
     }
 }
diff --git a/crates/client/txpool/Cargo.toml b/crates/client/txpool/Cargo.toml
index 9f9f25b6..990f00f6 100644
--- a/crates/client/txpool/Cargo.toml
+++ b/crates/client/txpool/Cargo.toml
@@ -14,6 +14,7 @@ workspace = true
 [dependencies]
 # workspace
 base-client-node.workspace = true
+base-flashblocks.workspace = true
 
 # reth
 reth-tracing.workspace = true
diff --git a/crates/client/txpool/src/events.rs b/crates/client/txpool/src/events.rs
index 7ca9faf5..c5d7b902 100644
--- a/crates/client/txpool/src/events.rs
+++ b/crates/client/txpool/src/events.rs
@@ -23,6 +23,9 @@ pub enum TxEvent {
     /// Transaction included on chain.
     #[display("block_inclusion")]
     BlockInclusion,
+    /// Transaction included in a flashblock.
+    #[display("fb_inclusion")]
+    FbInclusion,
     /// Transaction moved from pending -> queued.
     #[display("pending_to_queued")]
     PendingToQueued,
diff --git a/crates/client/txpool/src/extension.rs b/crates/client/txpool/src/extension.rs
index 0689dd49..e1747a96 100644
--- a/crates/client/txpool/src/extension.rs
+++ b/crates/client/txpool/src/extension.rs
@@ -1,7 +1,10 @@
 //! Contains the [`TxPoolExtension`] which wires up the transaction pool features
 //! (tracing subscription and status RPC) on the Base node builder.
 
+use std::sync::Arc;
+
 use base_client_node::{BaseBuilder, BaseNodeExtension, FromExtensionConfig};
+use base_flashblocks::{FlashblocksConfig, FlashblocksState};
 use reth_provider::CanonStateSubscriptions;
 use tokio_stream::wrappers::BroadcastStream;
 use tracing::info;
@@ -17,6 +20,8 @@ pub struct TxpoolConfig {
     pub tracing_logs_enabled: bool,
     /// Sequencer RPC endpoint for transaction status proxying.
     pub sequencer_rpc: Option<String>,
+    /// Optional Flashblocks configuration (includes state).
+    pub flashblocks_config: Option<FlashblocksConfig>,
 }
 
 /// Helper struct that wires the transaction pool features into the node builder.
@@ -42,6 +47,7 @@ impl BaseNodeExtension for TxPoolExtension {
         let sequencer_rpc = config.sequencer_rpc;
         let tracing_enabled = config.tracing_enabled;
         let logs_enabled = config.tracing_logs_enabled;
+        let flashblocks_config = config.flashblocks_config;
 
         builder.add_rpc_module(move |ctx| {
             info!(message = "Starting Transaction Status RPC");
@@ -54,7 +60,17 @@ impl BaseNodeExtension for TxPoolExtension {
                 let canonical_stream =
                     BroadcastStream::new(ctx.provider().subscribe_to_canonical_state());
                 let pool = ctx.pool().clone();
-                tokio::spawn(tracex_subscription(canonical_stream, pool, logs_enabled));
+
+                // Get flashblocks state from config if available
+                let flashblocks_state: Option<Arc<FlashblocksState>> =
+                    flashblocks_config.as_ref().map(|cfg| cfg.state.clone());
+
+                tokio::spawn(tracex_subscription(
+                    canonical_stream,
+                    flashblocks_state,
+                    pool,
+                    logs_enabled,
+                ));
             }
 
             Ok(())
diff --git a/crates/client/txpool/src/metrics.rs b/crates/client/txpool/src/metrics.rs
index b27ef7fb..14913bb3 100644
--- a/crates/client/txpool/src/metrics.rs
+++ b/crates/client/txpool/src/metrics.rs
@@ -14,4 +14,9 @@ pub struct Metrics {
         describe = "Time taken for a transaction to be included in a block from when it's marked as pending"
     )]
     pub inclusion_duration: Histogram,
+    /// Time taken for a transaction to be included in a flashblock from when it's marked as pending.
+    #[metric(
+        describe = "Time taken for a transaction to be included in a flashblock from when it's marked as pending"
+    )]
+    pub fb_inclusion_duration: Histogram,
 }
diff --git a/crates/client/txpool/src/subscription.rs b/crates/client/txpool/src/subscription.rs
index f02666de..7dff5679 100644
--- a/crates/client/txpool/src/subscription.rs
+++ b/crates/client/txpool/src/subscription.rs
@@ -1,10 +1,14 @@
 //! Tracex canonical block subscription.
 
+use std::sync::Arc;
+
+use base_flashblocks::{FlashblocksAPI, PendingBlocks};
 use futures::StreamExt;
 use reth_node_api::NodePrimitives;
 use reth_provider::CanonStateNotification;
 use reth_tracing::tracing::debug;
 use reth_transaction_pool::TransactionPool;
+use tokio::sync::broadcast::Receiver;
 use tokio_stream::wrappers::BroadcastStream;
 
 use crate::tracker::Tracker;
@@ -12,14 +16,16 @@ use crate::tracker::Tracker;
 /// Subscription task that tracks transaction timing from mempool to block inclusion.
 ///
 /// Monitors transaction lifecycle events and records timing metrics by listening
-/// to canonical state notifications and mempool events.
-pub async fn tracex_subscription<N, Pool>(
+/// to canonical state notifications, flashblock updates, and mempool events.
+pub async fn tracex_subscription<N, Pool, FB>(
     canonical_stream: BroadcastStream<CanonStateNotification<N>>,
+    flashblocks_api: Option<Arc<FB>>,
     pool: Pool,
     enable_logs: bool,
 ) where
     N: NodePrimitives,
     Pool: TransactionPool + 'static,
+    FB: FlashblocksAPI + 'static,
 {
     debug!(target: "tracex", "Starting transaction tracking subscription");
     let mut tracker = Tracker::new(enable_logs);
@@ -28,6 +34,10 @@ pub async fn tracex_subscription<N, Pool>(
     let mut all_events_stream = pool.all_transactions_event_listener();
     let mut canonical_stream = canonical_stream;
 
+    // Subscribe to flashblocks if available
+    let mut flashblock_stream: Option<Receiver<Arc<PendingBlocks>>> =
+        flashblocks_api.map(|api| api.subscribe_to_flashblocks());
+
     loop {
         tokio::select! {
             // Track # of transactions dropped and replaced.
@@ -37,6 +47,16 @@ pub async fn tracex_subscription<N, Pool>(
             Some(Ok(notification)) = canonical_stream.next() => {
                 tracker.handle_canon_state_notification(notification);
             }
+
+            // Track flashblock inclusion timing.
+            Ok(pending_blocks) = async {
+                match &mut flashblock_stream {
+                    Some(stream) => stream.recv().await,
+                    None => std::future::pending().await,
+                }
+            } => {
+                tracker.handle_flashblock_notification(pending_blocks);
+            }
         }
     }
 }
diff --git a/crates/client/txpool/src/tracker.rs b/crates/client/txpool/src/tracker.rs
index 366530f8..d7420d29 100644
--- a/crates/client/txpool/src/tracker.rs
+++ b/crates/client/txpool/src/tracker.rs
@@ -2,10 +2,12 @@
 
 use std::{
     num::NonZeroUsize,
+    sync::Arc,
     time::{Duration, Instant},
 };
 
 use alloy_primitives::TxHash;
+use base_flashblocks::PendingBlocks;
 use chrono::Local;
 use lru::LruCache;
 use reth_node_api::{BlockBody, NodePrimitives};
@@ -75,6 +77,11 @@ impl Tracker {
         self.track_committed_chain(&notification.committed());
     }
 
+    /// Parse flashblock updates and track transaction inclusion in flashblocks.
+    pub fn handle_flashblock_notification(&mut self, pending_blocks: Arc<PendingBlocks>) {
+        self.track_flashblock_transactions(&pending_blocks);
+    }
+
     fn track_committed_chain<N: NodePrimitives>(&mut self, chain: &Chain<N>) {
         for block in chain.blocks().values() {
             for transaction in block.body().transactions() {
@@ -83,6 +90,13 @@ impl Tracker {
         }
     }
 
+    fn track_flashblock_transactions(&mut self, pending_blocks: &PendingBlocks) {
+        // Get all transaction hashes from pending blocks
+        for tx_hash in pending_blocks.get_pending_transaction_hashes() {
+            self.transaction_fb_included(tx_hash);
+        }
+    }
+
     /// Track the first time we see a transaction in the mempool.
     pub fn transaction_inserted(&mut self, tx_hash: TxHash, event: TxEvent) {
         // If we've seen the tx before, don't track it again. For example,
@@ -170,6 +184,27 @@ impl Tracker {
         }
     }
 
+    /// Track a transaction being included in a flashblock.
+    pub fn transaction_fb_included(&mut self, tx_hash: TxHash) {
+        // Only track if we have seen this transaction before
+        if let Some(event_log) = self.txs.peek(&tx_hash) {
+            // Record `fb_inclusion_duration` metric if transaction was pending
+            if let Some(pending_time) = event_log.pending_time {
+                let time_pending_to_fb_inclusion = Instant::now().duration_since(pending_time);
+                self.metrics
+                    .fb_inclusion_duration
+                    .record(time_pending_to_fb_inclusion.as_millis() as f64);
+
+                debug!(
+                    target: "tracex",
+                    tx_hash = ?tx_hash,
+                    duration_ms = time_pending_to_fb_inclusion.as_millis(),
+                    "Transaction included in flashblock"
+                );
+            }
+        }
+    }
+
     /// Track a transaction being replaced by removing it from the cache and adding the new tx.
     pub fn transaction_replaced(&mut self, tx_hash: TxHash, replaced_by: TxHash) {
         if let Some(mut event_log) = self.txs.pop(&tx_hash) {

From d7703cfb44085f535ae6b23990e92bf716af78cf Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Wed, 14 Jan 2026 13:47:33 -0500
Subject: [PATCH 2/9] add test

---
 Cargo.lock                          |  6 ++++
 crates/client/txpool/Cargo.toml     |  7 +++++
 crates/client/txpool/src/tracker.rs | 48 +++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index 1e30b121..daf8a1d2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2136,6 +2136,8 @@ dependencies = [
 name = "base-txpool"
 version = "0.0.0"
 dependencies = [
+ "alloy-consensus",
+ "alloy-eips",
  "alloy-primitives",
  "base-client-node",
  "base-flashblocks",
@@ -2148,11 +2150,15 @@ dependencies = [
  "lru 0.16.3",
  "metrics",
  "metrics-derive",
+ "op-alloy-consensus",
+ "op-alloy-rpc-types",
  "reth-node-api",
+ "reth-optimism-primitives",
  "reth-primitives-traits",
  "reth-provider",
  "reth-tracing",
  "reth-transaction-pool",
+ "revm-database 9.0.6",
  "serde",
  "serde_json",
  "tokio",
diff --git a/crates/client/txpool/Cargo.toml b/crates/client/txpool/Cargo.toml
index 990f00f6..cec938bb 100644
--- a/crates/client/txpool/Cargo.toml
+++ b/crates/client/txpool/Cargo.toml
@@ -48,3 +48,10 @@ eyre.workspace = true
 httpmock.workspace = true
 serde_json.workspace = true
 reth-transaction-pool = { workspace = true, features = ["test-utils"] }
+base-flashblocks = { workspace = true, features = ["test-utils"] }
+alloy-consensus.workspace = true
+alloy-eips.workspace = true
+op-alloy-consensus.workspace = true
+op-alloy-rpc-types.workspace = true
+reth-optimism-primitives.workspace = true
+revm-database.workspace = true
diff --git a/crates/client/txpool/src/tracker.rs b/crates/client/txpool/src/tracker.rs
index d7420d29..00e862ca 100644
--- a/crates/client/txpool/src/tracker.rs
+++ b/crates/client/txpool/src/tracker.rs
@@ -256,8 +256,32 @@ impl Tracker {
 
 #[cfg(test)]
 mod tests {
+    use std::sync::Arc;
+
+    use alloy_primitives::{map::HashMap, Address};
+    use base_client_node::test_utils::TestHarness;
+    use reth_optimism_primitives::OpTransactionSigned;
+    use reth_transaction_pool::test_utils::TransactionBuilder;
+
     use super::*;
 
+    // Test helper to create a transaction
+    fn create_test_transaction() -> OpTransactionSigned {
+        TransactionBuilder::default()
+            .nonce(0)
+            .gas_limit(21_000)
+            .max_fee_per_gas(1_000_000_000)
+            .max_priority_fee_per_gas(1_000_000_000)
+            .to(Address::random())
+            .value(1000)
+            .chain_id(901)
+            .into_eip1559()
+            .as_eip1559()
+            .unwrap()
+            .clone()
+            .into()
+    }
+
     #[test]
     fn test_transaction_inserted_pending() {
         let mut tracker = Tracker::new(false);
@@ -562,4 +586,28 @@ mod tests {
         assert_eq!(tracker.txs.len(), 1);
         assert!(tracker.txs.get(&tx_hash2).is_some());
     }
+
+    #[test]
+    fn test_transaction_fb_included_with_pending_time() {
+        let mut tracker = Tracker::new(false);
+        let tx_hash = TxHash::random();
+
+        // Insert a pending transaction
+        tracker.transaction_inserted(tx_hash, TxEvent::Pending);
+        tracker.transaction_moved(tx_hash, Pool::Pending);
+
+        // Verify pending_time is set
+        assert!(tracker.txs.get(&tx_hash).unwrap().pending_time.is_some());
+        let initial_metric_count = tracker.metrics.fb_inclusion_duration.get_sample_count();
+
+        // Track FB inclusion
+        tracker.transaction_fb_included(tx_hash);
+
+        // Verify transaction is still in cache (FB inclusion doesn't remove it)
+        assert!(tracker.txs.get(&tx_hash).is_some());
+
+        // Verify metric was recorded
+        let final_metric_count = tracker.metrics.fb_inclusion_duration.get_sample_count();
+        assert_eq!(final_metric_count, initial_metric_count + 1);
+    }
 }

From eadf4e4dac7107d2c6ce97ac2f071e4b7d3e4022 Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Thu, 15 Jan 2026 11:42:57 -0500
Subject: [PATCH 3/9] diffs

---
 Cargo.lock                            | 2 +-
 bin/node/src/cli.rs                   | 7 +------
 crates/client/txpool/src/extension.rs | 2 +-
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index daf8a1d2..6db8ab62 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2158,7 +2158,7 @@ dependencies = [
  "reth-provider",
  "reth-tracing",
  "reth-transaction-pool",
- "revm-database 9.0.6",
+ "revm-database",
  "serde",
  "serde_json",
  "tokio",
diff --git a/bin/node/src/cli.rs b/bin/node/src/cli.rs
index fb3588c9..fa4a0973 100644
--- a/bin/node/src/cli.rs
+++ b/bin/node/src/cli.rs
@@ -56,16 +56,11 @@ impl From<Args> for Option<FlashblocksConfig> {
 
 impl From<Args> for TxpoolConfig {
     fn from(args: Args) -> Self {
-        let flashblocks_config = args
-            .websocket_url
-            .as_ref()
-            .map(|url| FlashblocksConfig::new(url.clone(), args.max_pending_blocks_depth));
-
         Self {
             tracing_enabled: args.enable_transaction_tracing,
             tracing_logs_enabled: args.enable_transaction_tracing_logs,
             sequencer_rpc: args.rollup_args.sequencer,
-            flashblocks_config,
+            flashblocks_config: args.flashblocks_config,
         }
     }
 }
diff --git a/crates/client/txpool/src/extension.rs b/crates/client/txpool/src/extension.rs
index e1747a96..73bb598e 100644
--- a/crates/client/txpool/src/extension.rs
+++ b/crates/client/txpool/src/extension.rs
@@ -21,7 +21,7 @@ pub struct TxpoolConfig {
     /// Sequencer RPC endpoint for transaction status proxying.
     pub sequencer_rpc: Option<String>,
     /// Optional Flashblocks configuration (includes state).
-    pub flashblocks_config: Option<FlashblocksConfig>,
+    pub flashblocks_config: Option<FlashblocksConfig>, 
 }
 
 /// Helper struct that wires the transaction pool features into the node builder.

From e2fbf87cbf3c70bbcf1e6cded070a691081a2ec3 Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Thu, 15 Jan 2026 14:01:26 -0500
Subject: [PATCH 4/9] fix

---
 Cargo.lock                          |  1 +
 bin/node/src/cli.rs                 |  2 +-
 crates/client/txpool/Cargo.toml     |  2 +-
 crates/client/txpool/src/tracker.rs | 24 ------------------------
 4 files changed, 3 insertions(+), 26 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 6db8ab62..3b9fb2e7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2141,6 +2141,7 @@ dependencies = [
  "alloy-primitives",
  "base-client-node",
  "base-flashblocks",
+ "base-flashblocks-node",
  "chrono",
  "derive_more",
  "eyre",
diff --git a/bin/node/src/cli.rs b/bin/node/src/cli.rs
index fa4a0973..879d8efb 100644
--- a/bin/node/src/cli.rs
+++ b/bin/node/src/cli.rs
@@ -60,7 +60,7 @@ impl From<Args> for TxpoolConfig {
             tracing_enabled: args.enable_transaction_tracing,
             tracing_logs_enabled: args.enable_transaction_tracing_logs,
             sequencer_rpc: args.rollup_args.sequencer,
-            flashblocks_config: args.flashblocks_config,
+            flashblocks_config: args.websocket_url.map(|url| FlashblocksConfig::new(url, args.max_pending_blocks_depth)),
         }
     }
 }
diff --git a/crates/client/txpool/Cargo.toml b/crates/client/txpool/Cargo.toml
index cec938bb..f55aac13 100644
--- a/crates/client/txpool/Cargo.toml
+++ b/crates/client/txpool/Cargo.toml
@@ -48,7 +48,7 @@ eyre.workspace = true
 httpmock.workspace = true
 serde_json.workspace = true
 reth-transaction-pool = { workspace = true, features = ["test-utils"] }
-base-flashblocks = { workspace = true, features = ["test-utils"] }
+base-flashblocks-node = { workspace = true, features = ["test-utils"] }
 alloy-consensus.workspace = true
 alloy-eips.workspace = true
 op-alloy-consensus.workspace = true
diff --git a/crates/client/txpool/src/tracker.rs b/crates/client/txpool/src/tracker.rs
index 00e862ca..0eeb8a87 100644
--- a/crates/client/txpool/src/tracker.rs
+++ b/crates/client/txpool/src/tracker.rs
@@ -586,28 +586,4 @@ mod tests {
         assert_eq!(tracker.txs.len(), 1);
         assert!(tracker.txs.get(&tx_hash2).is_some());
     }
-
-    #[test]
-    fn test_transaction_fb_included_with_pending_time() {
-        let mut tracker = Tracker::new(false);
-        let tx_hash = TxHash::random();
-
-        // Insert a pending transaction
-        tracker.transaction_inserted(tx_hash, TxEvent::Pending);
-        tracker.transaction_moved(tx_hash, Pool::Pending);
-
-        // Verify pending_time is set
-        assert!(tracker.txs.get(&tx_hash).unwrap().pending_time.is_some());
-        let initial_metric_count = tracker.metrics.fb_inclusion_duration.get_sample_count();
-
-        // Track FB inclusion
-        tracker.transaction_fb_included(tx_hash);
-
-        // Verify transaction is still in cache (FB inclusion doesn't remove it)
-        assert!(tracker.txs.get(&tx_hash).is_some());
-
-        // Verify metric was recorded
-        let final_metric_count = tracker.metrics.fb_inclusion_duration.get_sample_count();
-        assert_eq!(final_metric_count, initial_metric_count + 1);
-    }
 }

From 88b4fa7e51a5aec34b386707c713c7166e299552 Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Thu, 15 Jan 2026 15:39:33 -0500
Subject: [PATCH 5/9] add test

---
 Cargo.lock                          |   2 +
 crates/client/txpool/Cargo.toml     |   4 +-
 crates/client/txpool/src/tracker.rs | 136 +++++++++++++++++++++++-----
 3 files changed, 118 insertions(+), 24 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 3b9fb2e7..16724d4a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2139,9 +2139,11 @@ dependencies = [
  "alloy-consensus",
  "alloy-eips",
  "alloy-primitives",
+ "alloy-rpc-types-engine",
  "base-client-node",
  "base-flashblocks",
  "base-flashblocks-node",
+ "base-flashtypes",
  "chrono",
  "derive_more",
  "eyre",
diff --git a/crates/client/txpool/Cargo.toml b/crates/client/txpool/Cargo.toml
index f55aac13..2efeacdf 100644
--- a/crates/client/txpool/Cargo.toml
+++ b/crates/client/txpool/Cargo.toml
@@ -13,7 +13,7 @@ workspace = true
 
 [dependencies]
 # workspace
-base-client-node.workspace = true
+base-client-node = { workspace = true, features = ["test-utils"] }
 base-flashblocks.workspace = true
 
 # reth
@@ -55,3 +55,5 @@ op-alloy-consensus.workspace = true
 op-alloy-rpc-types.workspace = true
 reth-optimism-primitives.workspace = true
 revm-database.workspace = true
+base-flashtypes.workspace = true
+alloy-rpc-types-engine.workspace = true
diff --git a/crates/client/txpool/src/tracker.rs b/crates/client/txpool/src/tracker.rs
index 0eeb8a87..00146c2c 100644
--- a/crates/client/txpool/src/tracker.rs
+++ b/crates/client/txpool/src/tracker.rs
@@ -256,32 +256,23 @@ impl Tracker {
 
 #[cfg(test)]
 mod tests {
-    use std::sync::Arc;
-
-    use alloy_primitives::{map::HashMap, Address};
-    use base_client_node::test_utils::TestHarness;
-    use reth_optimism_primitives::OpTransactionSigned;
-    use reth_transaction_pool::test_utils::TransactionBuilder;
+    use std::ops::Deref;
+
+    use alloy_consensus::{SignableTransaction, TxEip1559};
+    use alloy_primitives::Address;
+    use base_client_node::test_utils::{SignerSync, L1_BLOCK_INFO_DEPOSIT_TX};
+    use alloy_eips::eip2718::Encodable2718;
+    use base_flashblocks::FlashblocksAPI;
+    use base_client_node::test_utils::Account;
+    use base_flashblocks_node::test_harness::FlashblocksHarness;
+    use base_flashtypes::{
+        ExecutionPayloadBaseV1, ExecutionPayloadFlashblockDeltaV1, Flashblock, Metadata,
+    };
+    use alloy_primitives::{Bytes, B256, U256};
+    use tokio::time;
 
     use super::*;
 
-    // Test helper to create a transaction
-    fn create_test_transaction() -> OpTransactionSigned {
-        TransactionBuilder::default()
-            .nonce(0)
-            .gas_limit(21_000)
-            .max_fee_per_gas(1_000_000_000)
-            .max_priority_fee_per_gas(1_000_000_000)
-            .to(Address::random())
-            .value(1000)
-            .chain_id(901)
-            .into_eip1559()
-            .as_eip1559()
-            .unwrap()
-            .clone()
-            .into()
-    }
-
     #[test]
     fn test_transaction_inserted_pending() {
         let mut tracker = Tracker::new(false);
@@ -586,4 +577,103 @@ mod tests {
         assert_eq!(tracker.txs.len(), 1);
         assert!(tracker.txs.get(&tx_hash2).is_some());
     }
+
+    fn build_eip1559_tx(
+        chain_id: u64,
+        nonce: u64,
+        to: Address,
+        value: U256,
+        input: Bytes,
+        account: Account,
+    ) -> Bytes {
+        let tx = TxEip1559 {
+            chain_id,
+            nonce,
+            gas_limit: 200_000,
+            max_fee_per_gas: 1_000_000_000,
+            max_priority_fee_per_gas: 1_000_000_000,
+            to: alloy_primitives::TxKind::Call(to),
+            value,
+            access_list: Default::default(),
+            input,
+        };
+    
+        let signature = account.signer().sign_hash_sync(&tx.signature_hash()).expect("signing works");
+        let signed = tx.into_signed(signature);
+    
+        signed.encoded_2718().into()
+    }    
+
+    #[tokio::test]
+    async fn test_receive_fb() -> eyre::Result<()> {
+        // Setup
+        let harness = FlashblocksHarness::new().await?;
+        let mut tracker = Tracker::new(false);
+
+        // Build transaction
+        let tx = build_eip1559_tx(
+            harness.chain_id(),
+            0,
+            Account::Alice.address(),
+            U256::ZERO,
+            Bytes::new(),
+            Account::Alice,
+        );
+        let tx_hash = alloy_primitives::keccak256(&tx);
+        let fb = Flashblock {
+            payload_id: alloy_rpc_types_engine::PayloadId::new([0; 8]),
+            index: 0,
+            base: Some(ExecutionPayloadBaseV1 {
+                parent_beacon_block_root: B256::default(),
+                parent_hash: B256::default(),
+                fee_recipient: Address::ZERO,
+                prev_randao: B256::default(),
+                block_number: 1,
+                gas_limit: 30_000_000,
+                timestamp: 0,
+                extra_data: Bytes::new(),
+                base_fee_per_gas: U256::ZERO,
+            }),
+            diff: ExecutionPayloadFlashblockDeltaV1 {
+                blob_gas_used: Some(0),
+                transactions: vec![L1_BLOCK_INFO_DEPOSIT_TX, tx],
+                ..Default::default()
+            },
+            metadata: Metadata { block_number: 1 },
+        };
+
+        // Mimic sending a tx to the mpool/builder
+        tracker.transaction_inserted(tx_hash, TxEvent::Pending);
+
+        // Wait a bit to simulate builder picking and building the tx into the pending block
+        time::sleep(Duration::from_millis(10)).await;
+        harness.send_flashblock(fb).await?;
+    
+        let state = harness.flashblocks_state().get_pending_blocks();
+        // Verify we have some pending transactions
+        let ptxs = state
+            .as_ref()
+            .map(|pb| pb.get_pending_transaction_hashes())
+            .unwrap_or_default();
+        assert_eq!(ptxs.len(), 2); // L1Info + tx
+        assert_eq!(ptxs[1], tx_hash);
+
+        let pb = state
+            .as_ref()
+            .unwrap()
+            .deref();
+        tracker.track_flashblock_transactions(pb);
+
+        // It should still be in the tracker
+        assert!(tracker.txs.get(&tx_hash).is_some());
+
+        // Wait until its included in canonical block
+        time::sleep(Duration::from_millis(1500)).await;
+        tracker.transaction_completed(tx_hash, TxEvent::BlockInclusion);
+
+        // It should be removed from the tracker
+        assert!(tracker.txs.get(&tx_hash).is_none());
+
+        Ok(())
+    }
 }

From 9c335b75819e4e1da95fe9abd4259e302b880d3d Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Thu, 15 Jan 2026 15:47:16 -0500
Subject: [PATCH 6/9] move out build_eip155_tx

---
 Cargo.lock                                    |  2 ++
 crates/client/flashblocks-node/Cargo.toml     |  1 +
 .../flashblocks-node/tests/eip7702_tests.rs   | 30 ++---------------
 crates/client/txpool/Cargo.toml               |  1 +
 crates/client/txpool/src/tracker.rs           | 31 ++---------------
 .../shared/primitives/src/test_utils/mod.rs   |  3 ++
 .../primitives/src/test_utils/transactions.rs | 33 +++++++++++++++++++
 7 files changed, 44 insertions(+), 57 deletions(-)
 create mode 100644 crates/shared/primitives/src/test_utils/transactions.rs

diff --git a/Cargo.lock b/Cargo.lock
index 16724d4a..466510c1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1984,6 +1984,7 @@ dependencies = [
  "base-flashblocks",
  "base-flashblocks-node",
  "base-flashtypes",
+ "base-primitives",
  "criterion",
  "derive_more",
  "eyre",
@@ -2144,6 +2145,7 @@ dependencies = [
  "base-flashblocks",
  "base-flashblocks-node",
  "base-flashtypes",
+ "base-primitives",
  "chrono",
  "derive_more",
  "eyre",
diff --git a/crates/client/flashblocks-node/Cargo.toml b/crates/client/flashblocks-node/Cargo.toml
index 81f648f7..b18080ea 100644
--- a/crates/client/flashblocks-node/Cargo.toml
+++ b/crates/client/flashblocks-node/Cargo.toml
@@ -29,6 +29,7 @@ workspace = true
 # workspace
 base-flashblocks.workspace = true
 base-client-node.workspace = true
+base-primitives.workspace = true
 
 # reth
 reth-chain-state.workspace = true
diff --git a/crates/client/flashblocks-node/tests/eip7702_tests.rs b/crates/client/flashblocks-node/tests/eip7702_tests.rs
index c30f6449..8259fcf9 100644
--- a/crates/client/flashblocks-node/tests/eip7702_tests.rs
+++ b/crates/client/flashblocks-node/tests/eip7702_tests.rs
@@ -3,7 +3,7 @@
 //! These tests verify that EIP-7702 authorization and delegation
 //! transactions work correctly in the pending/flashblocks state.
 
-use alloy_consensus::{SignableTransaction, TxEip1559, TxEip7702};
+use alloy_consensus::{SignableTransaction, TxEip7702};
 use alloy_eips::{eip2718::Encodable2718, eip7702::Authorization};
 use alloy_primitives::{Address, B256, Bytes, U256};
 use alloy_provider::Provider;
@@ -15,6 +15,7 @@ use base_flashblocks_node::test_harness::FlashblocksHarness;
 use base_flashtypes::{
     ExecutionPayloadBaseV1, ExecutionPayloadFlashblockDeltaV1, Flashblock, Metadata,
 };
+use base_primitives::build_eip1559_tx;
 use eyre::Result;
 use op_alloy_network::ReceiptResponse;
 
@@ -93,33 +94,6 @@ fn build_eip7702_tx(
     signed.encoded_2718().into()
 }
 
-/// Build and sign an EIP-1559 transaction
-fn build_eip1559_tx(
-    chain_id: u64,
-    nonce: u64,
-    to: Address,
-    value: U256,
-    input: Bytes,
-    account: Account,
-) -> Bytes {
-    let tx = TxEip1559 {
-        chain_id,
-        nonce,
-        gas_limit: 200_000,
-        max_fee_per_gas: 1_000_000_000,
-        max_priority_fee_per_gas: 1_000_000_000,
-        to: alloy_primitives::TxKind::Call(to),
-        value,
-        access_list: Default::default(),
-        input,
-    };
-
-    let signature = account.signer().sign_hash_sync(&tx.signature_hash()).expect("signing works");
-    let signed = tx.into_signed(signature);
-
-    signed.encoded_2718().into()
-}
-
 fn create_base_flashblock(setup: &TestSetup) -> Flashblock {
     Flashblock {
         payload_id: alloy_rpc_types_engine::PayloadId::new([0; 8]),
diff --git a/crates/client/txpool/Cargo.toml b/crates/client/txpool/Cargo.toml
index 2efeacdf..b025ab5d 100644
--- a/crates/client/txpool/Cargo.toml
+++ b/crates/client/txpool/Cargo.toml
@@ -57,3 +57,4 @@ reth-optimism-primitives.workspace = true
 revm-database.workspace = true
 base-flashtypes.workspace = true
 alloy-rpc-types-engine.workspace = true
+base-primitives.workspace = true
diff --git a/crates/client/txpool/src/tracker.rs b/crates/client/txpool/src/tracker.rs
index 00146c2c..49988628 100644
--- a/crates/client/txpool/src/tracker.rs
+++ b/crates/client/txpool/src/tracker.rs
@@ -258,16 +258,15 @@ impl Tracker {
 mod tests {
     use std::ops::Deref;
 
-    use alloy_consensus::{SignableTransaction, TxEip1559};
     use alloy_primitives::Address;
-    use base_client_node::test_utils::{SignerSync, L1_BLOCK_INFO_DEPOSIT_TX};
-    use alloy_eips::eip2718::Encodable2718;
+    use base_client_node::test_utils::L1_BLOCK_INFO_DEPOSIT_TX;
     use base_flashblocks::FlashblocksAPI;
     use base_client_node::test_utils::Account;
     use base_flashblocks_node::test_harness::FlashblocksHarness;
     use base_flashtypes::{
         ExecutionPayloadBaseV1, ExecutionPayloadFlashblockDeltaV1, Flashblock, Metadata,
     };
+    use base_primitives::build_eip1559_tx;
     use alloy_primitives::{Bytes, B256, U256};
     use tokio::time;
 
@@ -578,32 +577,6 @@ mod tests {
         assert!(tracker.txs.get(&tx_hash2).is_some());
     }
 
-    fn build_eip1559_tx(
-        chain_id: u64,
-        nonce: u64,
-        to: Address,
-        value: U256,
-        input: Bytes,
-        account: Account,
-    ) -> Bytes {
-        let tx = TxEip1559 {
-            chain_id,
-            nonce,
-            gas_limit: 200_000,
-            max_fee_per_gas: 1_000_000_000,
-            max_priority_fee_per_gas: 1_000_000_000,
-            to: alloy_primitives::TxKind::Call(to),
-            value,
-            access_list: Default::default(),
-            input,
-        };
-    
-        let signature = account.signer().sign_hash_sync(&tx.signature_hash()).expect("signing works");
-        let signed = tx.into_signed(signature);
-    
-        signed.encoded_2718().into()
-    }    
-
     #[tokio::test]
     async fn test_receive_fb() -> eyre::Result<()> {
         // Setup
diff --git a/crates/shared/primitives/src/test_utils/mod.rs b/crates/shared/primitives/src/test_utils/mod.rs
index 8626c87e..9a61e339 100644
--- a/crates/shared/primitives/src/test_utils/mod.rs
+++ b/crates/shared/primitives/src/test_utils/mod.rs
@@ -11,3 +11,6 @@ pub use contracts::{
     AccessListContract, ContractFactory, DoubleCounter, Logic, Logic2, Minimal7702Account,
     MockERC20, Proxy, SimpleStorage, TransparentUpgradeableProxy,
 };
+
+mod transactions;
+pub use transactions::build_eip1559_tx;
diff --git a/crates/shared/primitives/src/test_utils/transactions.rs b/crates/shared/primitives/src/test_utils/transactions.rs
new file mode 100644
index 00000000..961d57f2
--- /dev/null
+++ b/crates/shared/primitives/src/test_utils/transactions.rs
@@ -0,0 +1,33 @@
+use alloy_consensus::{SignableTransaction, TxEip1559};
+use alloy_eips::eip2718::Encodable2718;
+use alloy_primitives::{Address, Bytes, U256};
+use alloy_signer::SignerSync;
+
+use super::Account;
+
+/// Build and sign an EIP-1559 transaction
+pub fn build_eip1559_tx(
+    chain_id: u64,
+    nonce: u64,
+    to: Address,
+    value: U256,
+    input: Bytes,
+    account: Account,
+) -> Bytes {
+    let tx = TxEip1559 {
+        chain_id,
+        nonce,
+        gas_limit: 200_000,
+        max_fee_per_gas: 1_000_000_000,
+        max_priority_fee_per_gas: 1_000_000_000,
+        to: alloy_primitives::TxKind::Call(to),
+        value,
+        access_list: Default::default(),
+        input,
+    };
+
+    let signature = account.signer().sign_hash_sync(&tx.signature_hash()).expect("signing works");
+    let signed = tx.into_signed(signature);
+
+    signed.encoded_2718().into()
+}

From dd93848e812baafa802f9df58365474f5bea3ddc Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Thu, 15 Jan 2026 15:48:13 -0500
Subject: [PATCH 7/9] fmt

---
 bin/node/src/cli.rs                   |  4 +++-
 crates/client/txpool/src/extension.rs |  2 +-
 crates/client/txpool/src/tracker.rs   | 18 +++++-------------
 3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/bin/node/src/cli.rs b/bin/node/src/cli.rs
index 879d8efb..a2e92e18 100644
--- a/bin/node/src/cli.rs
+++ b/bin/node/src/cli.rs
@@ -60,7 +60,9 @@ impl From<Args> for TxpoolConfig {
             tracing_enabled: args.enable_transaction_tracing,
             tracing_logs_enabled: args.enable_transaction_tracing_logs,
             sequencer_rpc: args.rollup_args.sequencer,
-            flashblocks_config: args.websocket_url.map(|url| FlashblocksConfig::new(url, args.max_pending_blocks_depth)),
+            flashblocks_config: args
+                .websocket_url
+                .map(|url| FlashblocksConfig::new(url, args.max_pending_blocks_depth)),
         }
     }
 }
diff --git a/crates/client/txpool/src/extension.rs b/crates/client/txpool/src/extension.rs
index 73bb598e..e1747a96 100644
--- a/crates/client/txpool/src/extension.rs
+++ b/crates/client/txpool/src/extension.rs
@@ -21,7 +21,7 @@ pub struct TxpoolConfig {
     /// Sequencer RPC endpoint for transaction status proxying.
     pub sequencer_rpc: Option<String>,
     /// Optional Flashblocks configuration (includes state).
-    pub flashblocks_config: Option<FlashblocksConfig>, 
+    pub flashblocks_config: Option<FlashblocksConfig>,
 }
 
 /// Helper struct that wires the transaction pool features into the node builder.
diff --git a/crates/client/txpool/src/tracker.rs b/crates/client/txpool/src/tracker.rs
index 49988628..2a75f866 100644
--- a/crates/client/txpool/src/tracker.rs
+++ b/crates/client/txpool/src/tracker.rs
@@ -258,16 +258,14 @@ impl Tracker {
 mod tests {
     use std::ops::Deref;
 
-    use alloy_primitives::Address;
-    use base_client_node::test_utils::L1_BLOCK_INFO_DEPOSIT_TX;
+    use alloy_primitives::{Address, B256, Bytes, U256};
+    use base_client_node::test_utils::{Account, L1_BLOCK_INFO_DEPOSIT_TX};
     use base_flashblocks::FlashblocksAPI;
-    use base_client_node::test_utils::Account;
     use base_flashblocks_node::test_harness::FlashblocksHarness;
     use base_flashtypes::{
         ExecutionPayloadBaseV1, ExecutionPayloadFlashblockDeltaV1, Flashblock, Metadata,
     };
     use base_primitives::build_eip1559_tx;
-    use alloy_primitives::{Bytes, B256, U256};
     use tokio::time;
 
     use super::*;
@@ -621,20 +619,14 @@ mod tests {
         // Wait a bit to simulate builder picking and building the tx into the pending block
         time::sleep(Duration::from_millis(10)).await;
         harness.send_flashblock(fb).await?;
-    
+
         let state = harness.flashblocks_state().get_pending_blocks();
         // Verify we have some pending transactions
-        let ptxs = state
-            .as_ref()
-            .map(|pb| pb.get_pending_transaction_hashes())
-            .unwrap_or_default();
+        let ptxs = state.as_ref().map(|pb| pb.get_pending_transaction_hashes()).unwrap_or_default();
         assert_eq!(ptxs.len(), 2); // L1Info + tx
         assert_eq!(ptxs[1], tx_hash);
 
-        let pb = state
-            .as_ref()
-            .unwrap()
-            .deref();
+        let pb = state.as_ref().unwrap().deref();
         tracker.track_flashblock_transactions(pb);
 
         // It should still be in the tracker

From 0ac1b7357981b59f58c1d1e3f11ba342e7dda647 Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Thu, 15 Jan 2026 15:58:54 -0500
Subject: [PATCH 8/9] clippy

---
 crates/client/flashblocks-node/Cargo.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/client/flashblocks-node/Cargo.toml b/crates/client/flashblocks-node/Cargo.toml
index b18080ea..ab369cff 100644
--- a/crates/client/flashblocks-node/Cargo.toml
+++ b/crates/client/flashblocks-node/Cargo.toml
@@ -29,7 +29,6 @@ workspace = true
 # workspace
 base-flashblocks.workspace = true
 base-client-node.workspace = true
-base-primitives.workspace = true
 
 # reth
 reth-chain-state.workspace = true
@@ -46,6 +45,7 @@ reth-optimism-chainspec = { workspace = true, optional = true }
 
 
 [dev-dependencies]
+base-primitives.workspace = true
 base-client-node = { workspace = true, features = ["test-utils"] }
 base-flashblocks-node = { path = ".", features = ["test-utils"] }
 rand.workspace = true

From b268090ced5a0295e97b6e8262783a9b2184ff36 Mon Sep 17 00:00:00 2001
From: William Law <williamlaw.wtl@gmail.com>
Date: Thu, 15 Jan 2026 16:05:11 -0500
Subject: [PATCH 9/9] opt into fb wss

---
 crates/client/txpool/src/extension.rs    | 13 ++++---------
 crates/client/txpool/src/subscription.rs | 15 +++++----------
 crates/client/txpool/src/tracker.rs      |  3 ++-
 3 files changed, 11 insertions(+), 20 deletions(-)

diff --git a/crates/client/txpool/src/extension.rs b/crates/client/txpool/src/extension.rs
index e1747a96..50aee446 100644
--- a/crates/client/txpool/src/extension.rs
+++ b/crates/client/txpool/src/extension.rs
@@ -61,16 +61,11 @@ impl BaseNodeExtension for TxPoolExtension {
                     BroadcastStream::new(ctx.provider().subscribe_to_canonical_state());
                 let pool = ctx.pool().clone();
 
-                // Get flashblocks state from config if available
-                let flashblocks_state: Option<Arc<FlashblocksState>> =
-                    flashblocks_config.as_ref().map(|cfg| cfg.state.clone());
+                // Get flashblocks state from config, or create a default one if not configured
+                let fb_state: Arc<FlashblocksState> =
+                    flashblocks_config.as_ref().map(|cfg| cfg.state.clone()).unwrap_or_default();
 
-                tokio::spawn(tracex_subscription(
-                    canonical_stream,
-                    flashblocks_state,
-                    pool,
-                    logs_enabled,
-                ));
+                tokio::spawn(tracex_subscription(canonical_stream, fb_state, pool, logs_enabled));
             }
 
             Ok(())
diff --git a/crates/client/txpool/src/subscription.rs b/crates/client/txpool/src/subscription.rs
index 7dff5679..dbc47f61 100644
--- a/crates/client/txpool/src/subscription.rs
+++ b/crates/client/txpool/src/subscription.rs
@@ -19,7 +19,7 @@ use crate::tracker::Tracker;
 /// to canonical state notifications, flashblock updates, and mempool events.
 pub async fn tracex_subscription<N, Pool, FB>(
     canonical_stream: BroadcastStream<CanonStateNotification<N>>,
-    flashblocks_api: Option<Arc<FB>>,
+    flashblocks_api: Arc<FB>,
     pool: Pool,
     enable_logs: bool,
 ) where
@@ -34,9 +34,9 @@ pub async fn tracex_subscription<N, Pool, FB>(
     let mut all_events_stream = pool.all_transactions_event_listener();
     let mut canonical_stream = canonical_stream;
 
-    // Subscribe to flashblocks if available
-    let mut flashblock_stream: Option<Receiver<Arc<PendingBlocks>>> =
-        flashblocks_api.map(|api| api.subscribe_to_flashblocks());
+    // Subscribe to flashblocks.
+    let mut flashblock_stream: Receiver<Arc<PendingBlocks>> =
+        flashblocks_api.subscribe_to_flashblocks();
 
     loop {
         tokio::select! {
@@ -49,12 +49,7 @@ pub async fn tracex_subscription<N, Pool, FB>(
             }
 
             // Track flashblock inclusion timing.
-            Ok(pending_blocks) = async {
-                match &mut flashblock_stream {
-                    Some(stream) => stream.recv().await,
-                    None => std::future::pending().await,
-                }
-            } => {
+            Ok(pending_blocks) = flashblock_stream.recv() => {
                 tracker.handle_flashblock_notification(pending_blocks);
             }
         }
diff --git a/crates/client/txpool/src/tracker.rs b/crates/client/txpool/src/tracker.rs
index 2a75f866..7c057cdd 100644
--- a/crates/client/txpool/src/tracker.rs
+++ b/crates/client/txpool/src/tracker.rs
@@ -184,7 +184,8 @@ impl Tracker {
         }
     }
 
-    /// Track a transaction being included in a flashblock.
+    /// Track a transaction being included in a flashblock. This will not remove
+    /// the tx from the cache.
     pub fn transaction_fb_included(&mut self, tx_hash: TxHash) {
         // Only track if we have seen this transaction before
         if let Some(event_log) = self.txs.peek(&tx_hash) {