diff --git a/rollup/src/block.rs b/rollup/src/block.rs
index 56689c3..4bf4b33 100644
--- a/rollup/src/block.rs
+++ b/rollup/src/block.rs
@@ -8,11 +8,17 @@ use crate::{Signature, SignedTransaction, Signer};
 /// A block header containing metadata about the block.
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct BlockHeader {
+    /// The address of the sequencer that sealed the block.
     pub sequencer: Address,
+    /// The number of the block.
     pub number: u64,
+    /// The timestamp at the time the block was sealed.
     pub timestamp: u64,
+    /// The hash of the parent block. None if this is the genesis block.
     pub parent_digest: Option<String>,
+    /// The root digest of the withdrawals Merkle tree.
     pub withdrawals_root: String,
+    /// The root digest of the transactions Merkle tree.
     pub transactions_root: String,
 }
 
diff --git a/rollup/src/blockchain.rs b/rollup/src/blockchain.rs
index ce5e181..1c25c06 100644
--- a/rollup/src/blockchain.rs
+++ b/rollup/src/blockchain.rs
@@ -2,8 +2,11 @@ use crate::{transaction::DynamicTxData, Block, WithdrawalTxData};
 
 /// A blockchain containing a list of blocks and an incremental Merkle tree of withdrawals.
 pub(crate) struct Blockchain {
+    /// The chain of blocks in the blockchain.
     pub(crate) blocks: Vec<Block>,
+    /// The incremental Merkle tree of withdrawals.
     pub(crate) withdrawals_tree: imt::Tree<sha2::Sha256>,
+    /// The incremental Merkle tree of transactions.
     pub(crate) transactions_tree: imt::Tree<sha2::Sha256>,
 }
 
diff --git a/rollup/src/sequencer.rs b/rollup/src/sequencer.rs
index 9ece5a6..ffb0c4d 100644
--- a/rollup/src/sequencer.rs
+++ b/rollup/src/sequencer.rs
@@ -5,10 +5,14 @@ use crate::{
 /// Permissioned entity responsible for maintaining the canonical [Blockchain].
 /// Receives transactions directly and seals them into blocks.
 pub struct Sequencer {
+    /// The sequencer's signer used to sign blocks.
     signer: Signer,
+    /// The blockchain maintained by the sequencer.
     blockchain: Blockchain,
-    pool: Vec<SignedTransaction>,
-    withdrawals: Vec<SignedTransaction>,
+    /// The pool of transactions to be included in the next block.
+    transactions_pool: Vec<SignedTransaction>,
+    /// The pool of withdrawal transactions to be included in the next block.
+    withdrawals_pool: Vec<SignedTransaction>,
 }
 
 impl Sequencer {
@@ -17,8 +21,8 @@ impl Sequencer {
         Sequencer {
             signer: signer.into(),
             blockchain: Blockchain::default(),
-            pool: vec![],
-            withdrawals: vec![],
+            transactions_pool: vec![],
+            withdrawals_pool: vec![],
         }
     }
 
@@ -27,11 +31,11 @@ impl Sequencer {
         match &transaction.transaction {
             Transaction::Withdrawal(tx) => {
                 self.blockchain.withdraw(tx);
-                self.withdrawals.push(transaction);
+                self.withdrawals_pool.push(transaction);
             }
             Transaction::Dynamic(tx) => {
                 self.blockchain.transact(tx);
-                self.pool.push(transaction);
+                self.transactions_pool.push(transaction);
             }
         }
     }
@@ -51,9 +55,9 @@ impl Sequencer {
         // Drain the transaction pools and construct the block.
         let block = Block::new(
             SignedBlockHeader::new(header, &self.signer),
-            self.pool
+            self.transactions_pool
                 .drain(..)
-                .chain(self.withdrawals.drain(..))
+                .chain(self.withdrawals_pool.drain(..))
                 .collect(),
         );
         self.blockchain.push(block.clone());
diff --git a/rollup/src/signer.rs b/rollup/src/signer.rs
index a665ec9..fcac587 100644
--- a/rollup/src/signer.rs
+++ b/rollup/src/signer.rs
@@ -10,8 +10,11 @@ use std::str::FromStr;
 /// A recoverable seckp256k1 signature.
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Signature {
+    /// The r component of the signature.
     pub r: U256,
+    /// The s component of the signature.
     pub s: U256,
+    /// The recovery id of the signature.
     pub recovery_id: i32,
 }
 
diff --git a/rollup/src/transaction.rs b/rollup/src/transaction.rs
index a56bcca..dfab71d 100644
--- a/rollup/src/transaction.rs
+++ b/rollup/src/transaction.rs
@@ -7,17 +7,22 @@ use crate::signer::{Signature, Signer};
 /// A transaction header containing metadata about the transaction.
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct TransactionHeader {
-    chain_id: u64,
+    /// The address of the sender of the transaction.
     sender: Address,
+    /// The address of the recipient of the transaction.
     recipient: Address,
+    /// The amount of value transferred by the transaction.
     amount: u64,
 }
 
 /// A dynamic transaction containing a transaction header and dynamic fee data.
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct DynamicTxData {
+    /// The transaction header.
     header: TransactionHeader,
+    /// The maximum fee per gas that the sender is willing to pay.
     max_fee_per_gas: u64,
+    /// The maximum priority fee per gas that the sender is willing to pay.
     max_priority_fee_per_gas: u64,
 }
 
@@ -32,7 +37,9 @@ impl DynamicTxData {
 /// A withdrawal transaction containing a transaction header and destination.
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct WithdrawalTxData {
+    /// The transaction header.
     header: TransactionHeader,
+    /// The destination chain of the withdrawal.
     dest_chain: u64,
 }
 
@@ -58,7 +65,6 @@ impl Transaction {
     pub fn dynamic(sender: Address, amount: u64) -> Self {
         Transaction::Dynamic(DynamicTxData {
             header: TransactionHeader {
-                chain_id: 1,
                 sender,
                 recipient: Address::random(),
                 amount,
@@ -72,7 +78,6 @@ impl Transaction {
     pub fn withdrawal(sender: Address, amount: u64, dest_chain: u64) -> Self {
         Transaction::Withdrawal(WithdrawalTxData {
             header: TransactionHeader {
-                chain_id: 1,
                 sender,
                 recipient: sender,
                 amount,