diff --git a/Cargo.lock b/Cargo.lock
index 1f645243b1..55206b1d3c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -111,7 +111,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5674914c2cfdb866c21cb0c09d82374ee39a1395cf512e7515f4c014083b3fff"
 dependencies = [
  "alloy-primitives",
+ "arbitrary",
  "num_enum",
+ "proptest",
  "serde",
  "strum",
 ]
@@ -4455,6 +4457,7 @@ dependencies = [
 name = "kona-genesis"
 version = "0.3.0"
 dependencies = [
+ "alloy-chains",
  "alloy-consensus",
  "alloy-eips",
  "alloy-hardforks",
@@ -4633,6 +4636,7 @@ dependencies = [
 name = "kona-node-service"
 version = "0.1.0"
 dependencies = [
+ "alloy-chains",
  "alloy-eips",
  "alloy-primitives",
  "alloy-provider",
@@ -4686,6 +4690,7 @@ dependencies = [
 name = "kona-p2p"
 version = "0.1.0"
 dependencies = [
+ "alloy-chains",
  "alloy-consensus",
  "alloy-eips",
  "alloy-primitives",
diff --git a/bin/host/src/interop/cfg.rs b/bin/host/src/interop/cfg.rs
index 7b39d87041..435314c576 100644
--- a/bin/host/src/interop/cfg.rs
+++ b/bin/host/src/interop/cfg.rs
@@ -223,7 +223,7 @@ impl InteropHost {
             // Deserialize the config and return it.
             let cfg: RollupConfig = serde_json::from_str(&ser_config)?;
 
-            acc.insert(cfg.l2_chain_id, cfg);
+            acc.insert(cfg.l2_chain_id.id(), cfg);
             Ok(acc)
         })
     }
diff --git a/bin/node/src/commands/node.rs b/bin/node/src/commands/node.rs
index 811c424d01..3f4f25fc97 100644
--- a/bin/node/src/commands/node.rs
+++ b/bin/node/src/commands/node.rs
@@ -218,7 +218,7 @@ impl NodeCommand {
 
         info!(
             target: "rollup_node",
-            chain_id = cfg.l2_chain_id,
+            chain_id = cfg.l2_chain_id.id(),
             "Starting rollup node services"
         );
         for hf in cfg.hardforks.to_string().lines() {
diff --git a/bin/supervisor/src/flags/supervisor.rs b/bin/supervisor/src/flags/supervisor.rs
index cc48636434..e535ef1faf 100644
--- a/bin/supervisor/src/flags/supervisor.rs
+++ b/bin/supervisor/src/flags/supervisor.rs
@@ -135,7 +135,7 @@ impl SupervisorArgs {
 
             rollup_config_set
                 .add_from_rollup_config(
-                    chain_id,
+                    chain_id.id(),
                     rollup_config,
                     BlockInfo::new(
                         l1_genesis.header.hash,
diff --git a/crates/node/p2p/Cargo.toml b/crates/node/p2p/Cargo.toml
index 1ec401f7a7..b0d47d25b6 100644
--- a/crates/node/p2p/Cargo.toml
+++ b/crates/node/p2p/Cargo.toml
@@ -62,6 +62,7 @@ kona-cli.workspace = true
 multihash.workspace = true
 alloy-eips.workspace = true
 serde_json.workspace = true
+alloy-chains.workspace = true
 
 rand = { workspace = true, features = ["thread_rng"] }
 arbitrary = { workspace = true, features = ["derive"] }
diff --git a/crates/node/p2p/src/gossip/behaviour.rs b/crates/node/p2p/src/gossip/behaviour.rs
index 14b5a3f5f9..a145096ede 100644
--- a/crates/node/p2p/src/gossip/behaviour.rs
+++ b/crates/node/p2p/src/gossip/behaviour.rs
@@ -92,6 +92,7 @@ impl Behaviour {
 mod tests {
     use super::*;
     use crate::gossip::{config, handler::BlockHandler};
+    use alloy_chains::Chain;
     use alloy_primitives::Address;
     use kona_genesis::RollupConfig;
     use libp2p::gossipsub::{IdentTopic, TopicHash};
@@ -118,8 +119,10 @@ mod tests {
         let key = libp2p::identity::Keypair::generate_secp256k1();
         let cfg = config::default_config();
         let (_, recv) = tokio::sync::watch::channel(Address::default());
-        let block_handler =
-            BlockHandler::new(RollupConfig { l2_chain_id: 10, ..Default::default() }, recv);
+        let block_handler = BlockHandler::new(
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
+            recv,
+        );
         let handlers: Vec<Box<dyn Handler>> = vec![Box::new(block_handler)];
         let behaviour = Behaviour::new(key.public(), cfg, &handlers).unwrap();
         let mut topics = behaviour.gossipsub.topics().cloned().collect::<Vec<TopicHash>>();
diff --git a/crates/node/p2p/src/gossip/block_validity.rs b/crates/node/p2p/src/gossip/block_validity.rs
index 8735f45a52..b395433b33 100644
--- a/crates/node/p2p/src/gossip/block_validity.rs
+++ b/crates/node/p2p/src/gossip/block_validity.rs
@@ -170,7 +170,7 @@ impl BlockHandler {
         }
 
         // CHECK: The signature is valid.
-        let msg = envelope.payload_hash.signature_message(self.rollup_config.l2_chain_id);
+        let msg = envelope.payload_hash.signature_message(self.rollup_config.l2_chain_id.id());
         let block_signer = *self.signer_recv.borrow();
 
         // The block has a valid signature.
@@ -256,7 +256,9 @@ impl BlockHandler {
 
 #[cfg(test)]
 pub(crate) mod tests {
+
     use super::*;
+    use alloy_chains::Chain;
     use alloy_consensus::{Block, EMPTY_OMMER_ROOT_HASH};
     use alloy_eips::{eip2718::Encodable2718, eip4895::Withdrawal};
     use alloy_primitives::{Address, B256, Bytes, Signature};
@@ -377,7 +379,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -405,7 +407,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -433,7 +435,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -461,7 +463,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -486,7 +488,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -514,7 +516,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -568,7 +570,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -596,7 +598,7 @@ pub(crate) mod tests {
 
         let (_, unsafe_signer) = tokio::sync::watch::channel(Address::default());
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -624,7 +626,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -646,7 +648,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -671,7 +673,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -701,7 +703,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -731,7 +733,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -763,7 +765,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -794,7 +796,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -842,7 +844,7 @@ pub(crate) mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
diff --git a/crates/node/p2p/src/gossip/driver.rs b/crates/node/p2p/src/gossip/driver.rs
index 6c6a50246b..eb4972c565 100644
--- a/crates/node/p2p/src/gossip/driver.rs
+++ b/crates/node/p2p/src/gossip/driver.rs
@@ -229,9 +229,9 @@ where
 
     /// Dials the given [`Enr`].
     pub fn dial(&mut self, enr: Enr) {
-        let validation = EnrValidation::validate(&enr, self.handler.rollup_config.l2_chain_id);
+        let validation = EnrValidation::validate(&enr, self.handler.rollup_config.l2_chain_id.id());
         if validation.is_invalid() {
-            trace!(target: "gossip", "Invalid OP Stack ENR for chain id {}: {}", self.handler.rollup_config.l2_chain_id, validation);
+            trace!(target: "gossip", "Invalid OP Stack ENR for chain id {}: {}", self.handler.rollup_config.l2_chain_id.id(), validation);
             return;
         }
         let Some(multiaddr) = enr_to_multiaddr(&enr) else {
diff --git a/crates/node/p2p/src/gossip/handler.rs b/crates/node/p2p/src/gossip/handler.rs
index 35ea0df625..82e27c551c 100644
--- a/crates/node/p2p/src/gossip/handler.rs
+++ b/crates/node/p2p/src/gossip/handler.rs
@@ -90,7 +90,7 @@ impl BlockHandler {
     ///
     /// Requires the chain ID and a receiver channel for the unsafe block signer.
     pub fn new(rollup_config: RollupConfig, signer_recv: Receiver<Address>) -> Self {
-        let chain_id = rollup_config.l2_chain_id;
+        let chain_id = rollup_config.l2_chain_id.id();
         Self {
             rollup_config,
             signer_recv,
@@ -137,6 +137,7 @@ impl BlockHandler {
 
 #[cfg(test)]
 mod tests {
+    use alloy_chains::Chain;
     use alloy_rpc_types_engine::{ExecutionPayloadV2, ExecutionPayloadV3};
     use op_alloy_rpc_types_engine::{OpExecutionPayload, OpExecutionPayloadV4, PayloadHash};
 
@@ -163,7 +164,7 @@ mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -208,7 +209,7 @@ mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -242,7 +243,7 @@ mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -281,7 +282,7 @@ mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -320,7 +321,7 @@ mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -363,7 +364,7 @@ mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -405,7 +406,7 @@ mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
@@ -451,7 +452,7 @@ mod tests {
         let signer = envelope.signature.recover_address_from_prehash(&msg).unwrap();
         let (_, unsafe_signer) = tokio::sync::watch::channel(signer);
         let mut handler = BlockHandler::new(
-            RollupConfig { l2_chain_id: 10, ..Default::default() },
+            RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
             unsafe_signer,
         );
 
diff --git a/crates/node/p2p/tests/common/mod.rs b/crates/node/p2p/tests/common/mod.rs
index f06513e362..2c0acc068b 100644
--- a/crates/node/p2p/tests/common/mod.rs
+++ b/crates/node/p2p/tests/common/mod.rs
@@ -1,5 +1,6 @@
 //! Shared code for integration tests.
 
+use alloy_chains::Chain;
 use alloy_primitives::Address;
 use kona_genesis::RollupConfig;
 use kona_p2p::{Behaviour, BlockHandler, ConnectionGater, GaterConfig, GossipDriver};
@@ -22,7 +23,7 @@ pub(crate) fn gossip_driver(port: u16) -> GossipDriver<ConnectionGater> {
     let unsafe_block_signer = Address::default();
     let (_, unsafe_block_signer_recv) = tokio::sync::watch::channel(unsafe_block_signer);
     let handler = BlockHandler::new(
-        RollupConfig { l2_chain_id: 10, ..Default::default() },
+        RollupConfig { l2_chain_id: Chain::optimism_mainnet(), ..Default::default() },
         unsafe_block_signer_recv,
     );
     let behaviour = Behaviour::new(keypair.public(), config, &[Box::new(handler.clone())])
diff --git a/crates/node/service/Cargo.toml b/crates/node/service/Cargo.toml
index 75c0d5e20d..c48cdc7a82 100644
--- a/crates/node/service/Cargo.toml
+++ b/crates/node/service/Cargo.toml
@@ -26,6 +26,7 @@ kona-peers.workspace = true
 kona-macros.workspace = true
 
 # alloy
+alloy-chains.workspace = true
 alloy-signer.workspace = true
 alloy-signer-local.workspace = true
 alloy-primitives.workspace = true
diff --git a/crates/node/service/src/actors/network/builder.rs b/crates/node/service/src/actors/network/builder.rs
index e88b1ac4ca..481120ee90 100644
--- a/crates/node/service/src/actors/network/builder.rs
+++ b/crates/node/service/src/actors/network/builder.rs
@@ -61,7 +61,7 @@ impl NetworkBuilder {
         Self {
             discovery: Discv5Builder::new(
                 discovery_address,
-                rollup_config.l2_chain_id,
+                rollup_config.l2_chain_id.id(),
                 discovery_config,
             ),
             gossip: GossipDriverBuilder::new(
@@ -159,6 +159,7 @@ impl NetworkBuilder {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use alloy_chains::Chain;
     use discv5::{ConfigBuilder, ListenConfig, enr::CombinedKey};
     use libp2p::gossipsub::IdentTopic;
     use std::net::{IpAddr, Ipv4Addr, SocketAddr};
@@ -216,7 +217,10 @@ mod tests {
         gossip_addr.push(libp2p::multiaddr::Protocol::Tcp(gossip.port()));
 
         let driver = network_builder(NetworkBuilderParams {
-            rollup_config: RollupConfig { l2_chain_id: 10, ..Default::default() },
+            rollup_config: RollupConfig {
+                l2_chain_id: Chain::optimism_mainnet(),
+                ..Default::default()
+            },
             signer,
         })
         .with_gossip_address(gossip_addr.clone())
@@ -234,6 +238,7 @@ mod tests {
         // Block Handler Assertions
         assert_eq!(driver.gossip.handler.rollup_config.l2_chain_id, id);
         let v1 = IdentTopic::new(format!("/optimism/{}/0/blocks", id));
+        println!("{:?}", driver.gossip.handler.blocks_v1_topic);
         assert_eq!(driver.gossip.handler.blocks_v1_topic.hash(), v1.hash());
         let v2 = IdentTopic::new(format!("/optimism/{}/1/blocks", id));
         assert_eq!(driver.gossip.handler.blocks_v2_topic.hash(), v2.hash());
diff --git a/crates/proof/executor/src/builder/env.rs b/crates/proof/executor/src/builder/env.rs
index ace504d3b9..6842daaecc 100644
--- a/crates/proof/executor/src/builder/env.rs
+++ b/crates/proof/executor/src/builder/env.rs
@@ -41,7 +41,7 @@ where
     /// Returns the active [CfgEnv] for the executor.
     pub(crate) fn evm_cfg_env(&self, timestamp: u64) -> CfgEnv<OpSpecId> {
         CfgEnv::new()
-            .with_chain_id(self.config.l2_chain_id)
+            .with_chain_id(self.config.l2_chain_id.id())
             .with_spec(self.config.spec_id(timestamp))
     }
 
diff --git a/crates/protocol/genesis/Cargo.toml b/crates/protocol/genesis/Cargo.toml
index d554b99aaa..17e6e827d3 100644
--- a/crates/protocol/genesis/Cargo.toml
+++ b/crates/protocol/genesis/Cargo.toml
@@ -22,6 +22,7 @@ alloy-consensus.workspace = true
 alloy-eips.workspace = true
 alloy-hardforks.workspace = true
 alloy-op-hardforks.workspace = true
+alloy-chains.workspace = true
 
 # Misc
 thiserror.workspace = true
@@ -48,6 +49,7 @@ alloy-primitives = { workspace = true, features = ["rand", "arbitrary"] }
 default = []
 revm = [ "dep:op-revm" ]
 std = [
+	"alloy-chains/std",
 	"alloy-consensus/std",
 	"alloy-eips/std",
 	"alloy-primitives/std",
@@ -58,6 +60,7 @@ std = [
 	"thiserror/std",
 ]
 arbitrary = [
+	"alloy-chains/arbitrary",
 	"alloy-consensus/arbitrary",
 	"alloy-eips/arbitrary",
 	"alloy-primitives/arbitrary",
@@ -67,6 +70,7 @@ arbitrary = [
 	"std",
 ]
 serde = [
+	"alloy-chains/serde",
 	"alloy-consensus/serde",
 	"alloy-eips/serde",
 	"alloy-primitives/serde",
diff --git a/crates/protocol/genesis/src/chain/config.rs b/crates/protocol/genesis/src/chain/config.rs
index 1424468218..9c99d6418a 100644
--- a/crates/protocol/genesis/src/chain/config.rs
+++ b/crates/protocol/genesis/src/chain/config.rs
@@ -1,6 +1,7 @@
 //! Contains the chain config type.
 
 use alloc::string::String;
+use alloy_chains::Chain;
 use alloy_eips::eip1559::BaseFeeParams;
 use alloy_primitives::Address;
 
@@ -138,7 +139,7 @@ impl ChainConfig {
         RollupConfig {
             genesis: self.genesis,
             l1_chain_id: self.l1_chain_id,
-            l2_chain_id: self.chain_id,
+            l2_chain_id: Chain::from(self.chain_id),
             block_time: self.block_time,
             seq_window_size: self.seq_window_size,
             max_sequencer_drift: self.max_sequencer_drift,
diff --git a/crates/protocol/genesis/src/rollup.rs b/crates/protocol/genesis/src/rollup.rs
index 69d6185920..7546127451 100644
--- a/crates/protocol/genesis/src/rollup.rs
+++ b/crates/protocol/genesis/src/rollup.rs
@@ -1,6 +1,7 @@
 //! Rollup Config Types
 
 use crate::{AltDAConfig, BaseFeeConfig, ChainGenesis, HardForkConfig, OP_MAINNET_BASE_FEE_CONFIG};
+use alloy_chains::Chain;
 use alloy_hardforks::{EthereumHardfork, EthereumHardforks, ForkCondition};
 use alloy_op_hardforks::{OpHardfork, OpHardforks};
 use alloy_primitives::Address;
@@ -57,7 +58,7 @@ pub struct RollupConfig {
     /// The L1 chain ID
     pub l1_chain_id: u64,
     /// The L2 chain ID
-    pub l2_chain_id: u64,
+    pub l2_chain_id: Chain,
     /// Hardfork timestamps.
     #[cfg_attr(feature = "serde", serde(flatten))]
     pub hardforks: HardForkConfig,
@@ -142,7 +143,7 @@ impl Default for RollupConfig {
             channel_timeout: 0,
             granite_channel_timeout: GRANITE_CHANNEL_TIMEOUT,
             l1_chain_id: 0,
-            l2_chain_id: 0,
+            l2_chain_id: Chain::from_id(0),
             hardforks: HardForkConfig::default(),
             batch_inbox_address: Address::ZERO,
             deposit_contract_address: Address::ZERO,
@@ -802,7 +803,7 @@ mod tests {
             channel_timeout: 300,
             granite_channel_timeout: GRANITE_CHANNEL_TIMEOUT,
             l1_chain_id: 3151908,
-            l2_chain_id: 1337,
+            l2_chain_id: Chain::from_id(1337),
             hardforks: HardForkConfig {
                 regolith_time: Some(0),
                 canyon_time: Some(0),
diff --git a/crates/protocol/protocol/src/batch/core.rs b/crates/protocol/protocol/src/batch/core.rs
index 7874b1eb4a..4361137958 100644
--- a/crates/protocol/protocol/src/batch/core.rs
+++ b/crates/protocol/protocol/src/batch/core.rs
@@ -54,7 +54,7 @@ impl Batch {
             BatchType::Span => {
                 let mut raw_span_batch = RawSpanBatch::decode(r)?;
                 let span_batch = raw_span_batch
-                    .derive(cfg.block_time, cfg.genesis.l2_time, cfg.l2_chain_id)
+                    .derive(cfg.block_time, cfg.genesis.l2_time, cfg.l2_chain_id.id())
                     .map_err(BatchDecodingError::SpanBatchError)?;
                 Ok(Self::Span(span_batch))
             }
diff --git a/crates/protocol/registry/src/test_utils/base_mainnet.rs b/crates/protocol/registry/src/test_utils/base_mainnet.rs
index 691f428fea..8f9b7f7dc5 100644
--- a/crates/protocol/registry/src/test_utils/base_mainnet.rs
+++ b/crates/protocol/registry/src/test_utils/base_mainnet.rs
@@ -1,5 +1,6 @@
 //! Base Mainnet Rollup Config.
 
+use alloy_chains::Chain;
 use alloy_eips::BlockNumHash;
 use alloy_op_hardforks::{
     BASE_MAINNET_CANYON_TIMESTAMP, BASE_MAINNET_ECOTONE_TIMESTAMP, BASE_MAINNET_FJORD_TIMESTAMP,
@@ -43,7 +44,7 @@ pub const BASE_MAINNET_CONFIG: RollupConfig = RollupConfig {
     channel_timeout: 300,
     granite_channel_timeout: 50,
     l1_chain_id: 1,
-    l2_chain_id: 8453,
+    l2_chain_id: Chain::base_mainnet(),
     hardforks: HardForkConfig {
         regolith_time: None,
         canyon_time: Some(BASE_MAINNET_CANYON_TIMESTAMP),
diff --git a/crates/protocol/registry/src/test_utils/base_sepolia.rs b/crates/protocol/registry/src/test_utils/base_sepolia.rs
index 3c367c84d1..ae01fde068 100644
--- a/crates/protocol/registry/src/test_utils/base_sepolia.rs
+++ b/crates/protocol/registry/src/test_utils/base_sepolia.rs
@@ -1,5 +1,6 @@
 //! Base Sepolia Rollup Config.
 
+use alloy_chains::Chain;
 use alloy_eips::BlockNumHash;
 use alloy_op_hardforks::{
     BASE_SEPOLIA_CANYON_TIMESTAMP, BASE_SEPOLIA_ECOTONE_TIMESTAMP, BASE_SEPOLIA_FJORD_TIMESTAMP,
@@ -43,7 +44,7 @@ pub const BASE_SEPOLIA_CONFIG: RollupConfig = RollupConfig {
     channel_timeout: 300,
     granite_channel_timeout: 50,
     l1_chain_id: 11155111,
-    l2_chain_id: 84532,
+    l2_chain_id: Chain::base_sepolia(),
     chain_op_config: BASE_SEPOLIA_BASE_FEE_CONFIG,
     alt_da_config: None,
     hardforks: HardForkConfig {
diff --git a/crates/protocol/registry/src/test_utils/op_mainnet.rs b/crates/protocol/registry/src/test_utils/op_mainnet.rs
index 71495d3825..5797fff622 100644
--- a/crates/protocol/registry/src/test_utils/op_mainnet.rs
+++ b/crates/protocol/registry/src/test_utils/op_mainnet.rs
@@ -1,5 +1,6 @@
 //! OP Mainnet Rollup Config.
 
+use alloy_chains::Chain;
 use alloy_eips::BlockNumHash;
 use alloy_op_hardforks::{
     OP_MAINNET_CANYON_TIMESTAMP, OP_MAINNET_ECOTONE_TIMESTAMP, OP_MAINNET_FJORD_TIMESTAMP,
@@ -42,7 +43,7 @@ pub const OP_MAINNET_CONFIG: RollupConfig = RollupConfig {
     channel_timeout: 300_u64,
     granite_channel_timeout: 50,
     l1_chain_id: 1_u64,
-    l2_chain_id: 10_u64,
+    l2_chain_id: Chain::optimism_mainnet(),
     chain_op_config: OP_MAINNET_BASE_FEE_CONFIG,
     alt_da_config: None,
     hardforks: HardForkConfig {
diff --git a/crates/protocol/registry/src/test_utils/op_sepolia.rs b/crates/protocol/registry/src/test_utils/op_sepolia.rs
index f2647ee2b3..fb17de4abf 100644
--- a/crates/protocol/registry/src/test_utils/op_sepolia.rs
+++ b/crates/protocol/registry/src/test_utils/op_sepolia.rs
@@ -1,5 +1,6 @@
 //! OP Sepolia Rollup Config.
 
+use alloy_chains::Chain;
 use alloy_eips::BlockNumHash;
 use alloy_op_hardforks::{
     OP_SEPOLIA_CANYON_TIMESTAMP, OP_SEPOLIA_ECOTONE_TIMESTAMP, OP_SEPOLIA_FJORD_TIMESTAMP,
@@ -42,7 +43,7 @@ pub const OP_SEPOLIA_CONFIG: RollupConfig = RollupConfig {
     channel_timeout: 300,
     granite_channel_timeout: 50,
     l1_chain_id: 11155111,
-    l2_chain_id: 11155420,
+    l2_chain_id: Chain::optimism_sepolia(),
     chain_op_config: OP_SEPOLIA_BASE_FEE_CONFIG,
     alt_da_config: None,
     hardforks: HardForkConfig {