diff --git a/Lib9c/Action/ValidatorDelegation/SetValidatorCommission.cs b/Lib9c/Action/ValidatorDelegation/SetValidatorCommission.cs
index a0d4b0e278..405d8a3666 100644
--- a/Lib9c/Action/ValidatorDelegation/SetValidatorCommission.cs
+++ b/Lib9c/Action/ValidatorDelegation/SetValidatorCommission.cs
@@ -7,6 +7,9 @@
 
 namespace Nekoyume.Action.ValidatorDelegation
 {
+    /// <summary>
+    /// Set the commission percentage of the validator.
+    /// </summary>
     [ActionType(TypeIdentifier)]
     public sealed class SetValidatorCommission : ActionBase
     {
diff --git a/Lib9c/Delegation/Delegatee.cs b/Lib9c/Delegation/Delegatee.cs
index 6590f68b8e..8e16dedc10 100644
--- a/Lib9c/Delegation/Delegatee.cs
+++ b/Lib9c/Delegation/Delegatee.cs
@@ -165,12 +165,32 @@ public Address UnbondLockInAddress(Address delegatorAddress)
         public Address RebondGraceAddress(Address delegatorAddress)
             => Metadata.RebondGraceAddress(delegatorAddress);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the distribution pool
+        /// where the rewards are distributed from.
+        /// </summary>
+        /// <returns>
+        /// <see cref="Address"/> of the distribution pool.
+        /// </returns>
         public Address DistributionPoolAddress()
             => Metadata.DistributionPoolAddress();
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </summary>
+        /// <returns>
+        /// <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </returns>
         public Address CurrentRewardBaseAddress()
             => Metadata.CurrentRewardBaseAddress();
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </summary>
+        /// <param name="height"></param>
+        /// <returns>
+        /// <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </returns>
         public Address RewardBaseAddress(long height)
             => Metadata.RewardBaseAddress(height);
 
@@ -404,6 +424,13 @@ ImmutableDictionary<Currency, FungibleAssetValue> reward
             return reward;
         }
 
+        /// <summary>
+        /// Start a new reward period.
+        /// It generates a new <see cref="RewardBase"/> and archives the current one.
+        /// </summary>
+        /// <param name="height">
+        /// The height of the block where the new reward period starts.
+        /// </param>
         public void StartNewRewardPeriod(long height)
         {
             MigrateLumpSumRewardsRecords();
diff --git a/Lib9c/Delegation/DelegateeMetadata.cs b/Lib9c/Delegation/DelegateeMetadata.cs
index a322ea03d8..c94524f100 100644
--- a/Lib9c/Delegation/DelegateeMetadata.cs
+++ b/Lib9c/Delegation/DelegateeMetadata.cs
@@ -20,6 +20,47 @@ public class DelegateeMetadata : IDelegateeMetadata
         private Address? _address;
         private readonly IComparer<Currency> _currencyComparer = new CurrencyComparer();
 
+        /// <summary>
+        /// Create a new instance of DelegateeMetadata.
+        /// </summary>
+        /// <param name="delegateeAddress">
+        /// The <see cref="Address"/> of the <see cref="Delegatee{T, TSelf}"/>.
+        /// </param>
+        /// <param name="delegateeAccountAddress">
+        /// The <see cref="Address"/> of the account of the <see cref="Delegatee{T, TSelf}"/>.
+        /// </param>
+        /// <param name="delegationCurrency">
+        /// The <see cref="Currency"/> used for delegation.
+        /// </param>
+        /// <param name="rewardCurrencies">
+        /// The enumerable of <see cref="Currency"/>s used for reward.
+        /// </param>
+        /// <param name="delegationPoolAddress">
+        /// The <see cref="Address"/> of the delegation pool that stores
+        /// delegated <see cref="FungibleAssetValue"/>s.
+        /// </param>
+        /// <param name="rewardPoolAddress">
+        /// The <see cref="Address"/> of the reward pool that gathers
+        /// rewards to be distributed.
+        /// </param>
+        /// <param name="rewardRemainderPoolAddress">
+        /// The <see cref="Address"/> of the reward remainder pool to
+        /// sends the remainder of the rewards to.
+        /// </param>
+        /// <param name="slashedPoolAddress">
+        /// The <see cref="Address"/> of the pool that sends the slashed
+        /// <see cref="FungibleAssetValue"/>s to.
+        /// </param>
+        /// <param name="unbondingPeriod">
+        /// The period in blocks that the unbonded <see cref="FungibleAssetValue"/>s
+        /// can be withdrawn.
+        /// </param>
+        /// <param name="maxUnbondLockInEntries">
+        /// The maximum number of entries that can be locked in for unbonding.
+        /// </param>
+        /// <param name="maxRebondGraceEntries">
+        /// The maximum number of entries that can be locked in for rebonding.
+        /// </param>
         public DelegateeMetadata(
             Address delegateeAddress,
             Address delegateeAccountAddress,
@@ -340,18 +381,55 @@ public Address UnbondLockInAddress(Address delegatorAddress)
         public virtual Address RebondGraceAddress(Address delegatorAddress)
             => DelegationAddress.RebondGraceAddress(Address, delegatorAddress);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the distribution pool
+        /// where the rewards are distributed from.
+        /// </summary>
+        /// <returns>
+        /// <see cref="Address"/> of the distribution pool.
+        /// </returns>
         public virtual Address DistributionPoolAddress()
             => DelegationAddress.DistributionPoolAddress(Address);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </summary>
+        /// <returns>
+        /// <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </returns>
         public virtual Address CurrentRewardBaseAddress()
             => DelegationAddress.CurrentRewardBaseAddress(Address);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </summary>
+        /// <param name="height"></param>
+        /// <returns>
+        /// <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </returns>
         public virtual Address RewardBaseAddress(long height)
             => DelegationAddress.RewardBaseAddress(Address, height);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the current lump sum rewards record.
+        /// This will be removed after the migration is done.
+        /// </summary>
+        /// <returns>
+        /// <see cref="Address"/> of the current lump sum rewards record.
+        /// </returns>
         public virtual Address CurrentLumpSumRewardsRecordAddress()
             => DelegationAddress.CurrentRewardBaseAddress(Address);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the lump sum rewards record at the given height.
+        /// This will be removed after the migration is done.
+        /// </summary>
+        /// <param name="height">
+        /// The height of the lump sum rewards record.
+        /// </param>
+        /// <returns>
+        /// <see cref="Address"/> of the lump sum rewards record at the given height.
+        /// </returns>
         public virtual Address LumpSumRewardsRecordAddress(long height)
             => DelegationAddress.RewardBaseAddress(Address, height);
 
diff --git a/Lib9c/Delegation/DelegationAddress.cs b/Lib9c/Delegation/DelegationAddress.cs
index 1e7a340b92..4a850d65dd 100644
--- a/Lib9c/Delegation/DelegationAddress.cs
+++ b/Lib9c/Delegation/DelegationAddress.cs
@@ -65,18 +65,54 @@ public static Address RebondGraceAddress(
                 delegateeMetadataAddress,
                 delegatorAddress.ByteArray);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the current <see cref="RewardBase"/>. 
+        /// </summary>
+        /// <param name="delegateeAddress">
+        /// <see cref="Address"/> of the <see cref="Delegatee{T, TSelf}"/>.
+        /// </param>
+        /// <param name="delegateeAccountAddress">
+        /// <see cref="Address"/> of the account of the <see cref="Delegatee{T, TSelf}"/>.
+        /// </param>
+        /// <returns>
+        /// <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </returns>
         public static Address CurrentRewardBaseAddress(
             Address delegateeAddress, Address delegateeAccountAddress)
             => DeriveAddress(
                 DelegationElementType.RewardBase,
                 DelegateeMetadataAddress(delegateeAddress, delegateeAccountAddress));
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </summary>
+        /// <param name="delegateeMetadataAddress">
+        /// <see cref="Address"/> of the <see cref="DelegateeMetadata"/>.
+        /// </param>
+        /// <returns>
+        /// <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </returns>
         public static Address CurrentRewardBaseAddress(
             Address delegateeMetadataAddress)
             => DeriveAddress(
                 DelegationElementType.RewardBase,
                 delegateeMetadataAddress);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </summary>
+        /// <param name="delegateeAddress">
+        /// <see cref="Address"/> of the <see cref="Delegatee{T, TSelf}"/>.
+        /// </param>
+        /// <param name="delegateeAccountAddress">
+        /// <see cref="Address"/> of the account of the <see cref="Delegatee{T, TSelf}"/>.
+        /// </param>
+        /// <param name="height">
+        /// The height of the <see cref="RewardBase"/>.
+        /// </param>
+        /// <returns>
+        /// <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </returns>
         public static Address RewardBaseAddress(
             Address delegateeAddress, Address delegateeAccountAddress, long height)
             => DeriveAddress(
@@ -84,6 +120,18 @@ public static Address RewardBaseAddress(
                 DelegateeMetadataAddress(delegateeAddress, delegateeAccountAddress),
                 BitConverter.GetBytes(height));
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </summary>
+        /// <param name="delegateeMetadataAddress">
+        /// <see cref="Address"/> of the <see cref="DelegateeMetadata"/>.
+        /// </param>
+        /// <param name="height">
+        /// The height of the <see cref="RewardBase"/>.
+        /// </param>
+        /// <returns>
+        /// <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </returns>
         public static Address RewardBaseAddress(
             Address delegateeMetadataAddress, long height)
             => DeriveAddress(
@@ -103,12 +151,35 @@ public static Address RewardPoolAddress(
                 DelegationElementType.RewardPool,
                 delegateeMetadataAddress);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the distribution pool
+        /// where the rewards are distributed from.
+        /// </summary>
+        /// <param name="delegateeAddress">
+        /// <see cref="Address"/> of the <see cref="Delegatee{T, TSelf}"/>.
+        /// </param>
+        /// <param name="delegateeAccountAddress">
+        /// <see cref="Address"/> of the account of the <see cref="Delegatee{T, TSelf}"/>.
+        /// </param>
+        /// <returns>
+        /// <see cref="Address"/> of the distribution pool.
+        /// </returns>
         public static Address DistributionPoolAddress(
             Address delegateeAddress, Address delegateeAccountAddress)
             => DeriveAddress(
                 DelegationElementType.DistributionPool,
                 DelegateeMetadataAddress(delegateeAddress, delegateeAccountAddress));
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the distribution pool
+        /// where the rewards are distributed from.
+        /// </summary>
+        /// <param name="delegateeMetadataAddress">
+        /// <see cref="Address"/> of the <see cref="DelegateeMetadata"/>.
+        /// </param>
+        /// <returns>
+        /// <see cref="Address"/> of the distribution pool.
+        /// </returns>
         public static Address DistributionPoolAddress(
             Address delegateeMetadataAddress)
             => DeriveAddress(
diff --git a/Lib9c/Delegation/DelegationRepository.cs b/Lib9c/Delegation/DelegationRepository.cs
index d67bc2f614..26f33397b1 100644
--- a/Lib9c/Delegation/DelegationRepository.cs
+++ b/Lib9c/Delegation/DelegationRepository.cs
@@ -74,26 +74,59 @@ public DelegationRepository(
             .SetAccount(RewardBaseAccountAddress, rewardBaseAccount)
             .SetAccount(LumpSumRewardsRecordAccountAddress, lumpSumRewardsRecordAccount);
 
+        /// <summary>
+        /// <see cref="IActionContext"/> of the current action.
+        /// </summary>
         public IActionContext ActionContext { get; }
 
+        /// <summary>
+        /// <see cref="Address"> of the <see cref="Delegatee{T, TSelf}"> account.
+        /// </summary>
         public Address DelegateeAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"> of the <see cref="Delegator{T, TSelf}"> account.
+        /// </summary>
         public Address DelegatorAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"> of the <see cref="DelegateeMetadata"/> account.
+        /// </summary>
         public Address DelegateeMetadataAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"> of the <see cref="DelegatorMetadata"> account.
+        /// </summary>
         public Address DelegatorMetadataAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"/> of the <see cref="Bond"/> account.
+        /// </summary>
         public Address BondAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"/> of the <see cref="UnbondLockIn"/> account.
+        /// </summary>
         public Address UnbondLockInAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"/> of the <see cref="RebondGrace"/> account
+        /// </summary>
         public Address RebondGraceAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"/> of the <see cref="UnbondingSet"/> account.
+        /// </summary>
         public Address UnbondingSetAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"/> of the <see cref="RewardBase"/> account.
+        /// </summary>
         public Address RewardBaseAccountAddress { get; }
 
+        /// <summary>
+        /// <see cref="Address"/> of the <see cref="LumpSumRewardsRecord"/> account.
+        /// </summary>
         public Address LumpSumRewardsRecordAccountAddress { get; }
 
         public abstract IDelegatee GetDelegatee(Address address);
@@ -170,6 +203,7 @@ public UnbondingSet GetUnbondingSet()
                 ? new UnbondingSet(bencoded, this)
                 : new UnbondingSet(this);
 
+        /// <inheritdoc/>
         public RewardBase? GetCurrentRewardBase(IDelegatee delegatee)
         {
             Address address = delegatee.CurrentRewardBaseAddress();
@@ -179,6 +213,7 @@ public UnbondingSet GetUnbondingSet()
                 : null;
         }
 
+        /// <inheritdoc/>
         public RewardBase? GetRewardBase(IDelegatee delegatee, long height)
         {
             Address address = delegatee.RewardBaseAddress(height);
@@ -251,6 +286,7 @@ public void SetUnbondingSet(UnbondingSet unbondingSet)
                 : unbondingSetAccount.SetState(UnbondingSet.Address, unbondingSet.Bencoded);
         }
 
+        /// <inheritdoc/>
         public void SetRewardBase(RewardBase rewardBase)
         {
             rewardBaseAccount = rewardBaseAccount.SetState(rewardBase.Address, rewardBase.Bencoded);
@@ -262,6 +298,7 @@ public void SetLumpSumRewardsRecord(LumpSumRewardsRecord lumpSumRewardsRecord)
                 lumpSumRewardsRecord.Address, lumpSumRewardsRecord.Bencoded);
         }
 
+        /// <inheritdoc/>
         public void RemoveLumpSumRewardsRecord(LumpSumRewardsRecord lumpSumRewardsRecord)
         {
             lumpSumRewardsRecordAccount = lumpSumRewardsRecordAccount.RemoveState(lumpSumRewardsRecord.Address);
diff --git a/Lib9c/Delegation/IDelegatee.cs b/Lib9c/Delegation/IDelegatee.cs
index 54144830b1..463f9aaeb0 100644
--- a/Lib9c/Delegation/IDelegatee.cs
+++ b/Lib9c/Delegation/IDelegatee.cs
@@ -65,8 +65,23 @@ public interface IDelegatee
 
         Address RebondGraceAddress(Address delegatorAddress);
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </summary>
+        /// <returns>
+        /// The <see cref="Address"/> of the current <see cref="RewardBase"/>.
+        /// </returns>
         Address CurrentRewardBaseAddress();
 
+        /// <summary>
+        /// Get the <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </summary>
+        /// <param name="height">
+        /// The height of the <see cref="RewardBase"/>.
+        /// </param>
+        /// <returns>
+        /// The <see cref="Address"/> of the <see cref="RewardBase"/> at the given height.
+        /// </returns>
         Address RewardBaseAddress(long height);
 
         Address CurrentLumpSumRewardsRecordAddress();
diff --git a/Lib9c/Delegation/IDelegationRepository.cs b/Lib9c/Delegation/IDelegationRepository.cs
index c3520d4c41..cec2148a04 100644
--- a/Lib9c/Delegation/IDelegationRepository.cs
+++ b/Lib9c/Delegation/IDelegationRepository.cs
@@ -36,8 +36,31 @@ public interface IDelegationRepository
 
         UnbondingSet GetUnbondingSet();
 
+        /// <summary>
+        /// Get the current <see cref="RewardBase"/> of the <paramref name="delegatee"/>.
+        /// </summary>
+        /// <param name="delegatee">
+        /// The <see cref="IDelegatee"/> to get the current <see cref="RewardBase"/>.
+        /// </param>
+        /// <returns>
+        /// The current <see cref="RewardBase"/> of the <paramref name="delegatee"/>.
+        /// </returns>
         RewardBase? GetCurrentRewardBase(IDelegatee delegatee);
 
+        /// <summary>
+        /// Get the <see cref="RewardBase"/> of the <paramref name="delegatee"/>
+        /// at the given <paramref name="height"/>.
+        /// </summary>
+        /// <param name="delegatee">
+        /// The <see cref="IDelegatee"/> to get the <see cref="RewardBase"/> of.
+        /// </param>
+        /// <param name="height">
+        /// The height to get the <see cref="RewardBase"/> at.
+        /// </param>
+        /// <returns>
+        /// The <see cref="RewardBase"/> of the <paramref name="delegatee"/>
+        /// at the given <paramref name="height"/>.
+        /// </returns>
         RewardBase? GetRewardBase(IDelegatee delegatee, long height);
 
         LumpSumRewardsRecord? GetCurrentLumpSumRewardsRecord(IDelegatee delegatee);
@@ -62,10 +85,24 @@ public interface IDelegationRepository
 
         void SetUnbondingSet(UnbondingSet unbondingSet);
 
+        /// <summary>
+        /// Set the <see cref="RewardBase"/> of the <see cref="IDelegatee"/>.
+        /// </summary>
+        /// <param name="rewardBase">
+        /// The <see cref="RewardBase"/> to set.
+        /// </param>
         void SetRewardBase(RewardBase rewardBase);
 
         void SetLumpSumRewardsRecord(LumpSumRewardsRecord lumpSumRewardsRecord);
 
+        /// <summary>
+        /// Remove the <see cref="LumpSumRewardsRecord"/> from the <see cref="IDelegatee"/>.
+        /// This is used when the <see cref="LumpSumRewardsRecord"/> is no longer needed.
+        /// This can be removed when the migration for <see cref="RewardBase"/> is done.
+        /// </summary>
+        /// <param name="lumpSumRewardsRecord">
+        /// The <see cref="LumpSumRewardsRecord"/> to remove.
+        /// </param>
         void RemoveLumpSumRewardsRecord(LumpSumRewardsRecord lumpSumRewardsRecord);
 
         void TransferAsset(Address sender, Address recipient, FungibleAssetValue value);
diff --git a/Lib9c/ValidatorDelegation/AbstainHistory.cs b/Lib9c/ValidatorDelegation/AbstainHistory.cs
index deaedb1f12..3e67bab5b3 100644
--- a/Lib9c/ValidatorDelegation/AbstainHistory.cs
+++ b/Lib9c/ValidatorDelegation/AbstainHistory.cs
@@ -42,6 +42,9 @@ public AbstainHistory(List bencoded)
 
         public static int WindowSize => 10;
 
+        /// <summary>
+        /// Maximum abstain allowance to slash and jail.
+        /// </summary>
         public static int MaxAbstainAllowance => 9;
 
         public static Address Address => new Address(