diff --git a/.yardopts b/.yardopts
new file mode 100644
index 00000000..6750db65
--- /dev/null
+++ b/.yardopts
@@ -0,0 +1 @@
+--verbose --fail-on-warning --markup markdown --embed-mixins
diff --git a/lib/eth.rb b/lib/eth.rb
index 26b136fa..9f871f63 100644
--- a/lib/eth.rb
+++ b/lib/eth.rb
@@ -12,11 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 end
 
-# Loads the `Eth` module classes.
+# Loads the {Eth} module classes.
 require "eth/abi"
 require "eth/api"
 require "eth/address"
diff --git a/lib/eth/abi.rb b/lib/eth/abi.rb
index 9ebf7083..28046afa 100644
--- a/lib/eth/abi.rb
+++ b/lib/eth/abi.rb
@@ -18,7 +18,7 @@
 
 require "eth/abi/type"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides a Ruby implementation of the Ethereum Applicatoin Binary Interface (ABI).
@@ -69,7 +69,7 @@ def encode(types, args)
     # Encodes a specific value, either static or dynamic.
     #
     # @param type [Eth::Abi::Type] type to be encoded.
-    # @param arg [String, Number] value to be encoded.
+    # @param arg [String|Number] value to be encoded.
     # @return [String] the encoded type.
     # @raise [EncodingError] if value does not match type.
     def encode_type(type, arg)
@@ -111,7 +111,7 @@ def encode_type(type, arg)
     # Encodes primitive types.
     #
     # @param type [Eth::Abi::Type] type to be encoded.
-    # @param arg [String, Number] value to be encoded.
+    # @param arg [String|Number] value to be encoded.
     # @return [String] the encoded primitive type.
     # @raise [EncodingError] if value does not match type.
     # @raise [ValueOutOfBounds] if value is out of bounds for type.
diff --git a/lib/eth/abi/type.rb b/lib/eth/abi/type.rb
index 9ab72e08..81dba774 100644
--- a/lib/eth/abi/type.rb
+++ b/lib/eth/abi/type.rb
@@ -14,7 +14,7 @@
 
 # -*- encoding : ascii-8bit -*-
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides a Ruby implementation of the Ethereum Applicatoin Binary Interface (ABI).
@@ -26,7 +26,7 @@ class Type
       # Provides a specific parser error if type cannot be determined.
       class ParseError < StandardError; end
 
-      # The base attribute, e.g., `string` or `bytes`
+      # The base attribute, e.g., `string` or `bytes`.
       attr :base_type
 
       # The sub-type attribute, e.g., `256` as size of an uint256.
@@ -36,7 +36,7 @@ class ParseError < StandardError; end
       attr :dimensions
 
       # Create a new Type object for base types, sub types, and dimensions.
-      # Should use the `Type.parse` parser.
+      # Should not be used; use {Type.parse} instead.
       #
       # @param base_type [String] the base-type attribute.
       # @param sub_type [String] the sub-type attribute.
@@ -75,7 +75,7 @@ def parse(type)
         @dimensions = dims.map { |x| x[1...-1].to_i }
       end
 
-      # Creata new uint256 type used for size.
+      # Creates a new uint256 type used for size.
       #
       # @return [Eth::Abi::Type] a uint256 size type.
       def self.size_type
@@ -85,7 +85,7 @@ def self.size_type
       # Compares two types for their attributes.
       #
       # @param another_type [Eth::Abi::Type] another type to be compared.
-      # @return [Bool] true if all attributes match.
+      # @return [Boolean] true if all attributes match.
       def ==(another_type)
         base_type == another_type.base_type and
           sub_type == another_type.sub_type and
@@ -111,9 +111,9 @@ def size
         @size ||= s
       end
 
-      # Helper to determine whether array is of dynamic size.
+      # Helpes to determine whether array is of dynamic size.
       #
-      # @return [Bool] true if array is of dynamic size.
+      # @return [Boolean] true if array is of dynamic size.
       def is_dynamic?
         size.nil?
       end
diff --git a/lib/eth/address.rb b/lib/eth/address.rb
index 350cff84..7182a270 100644
--- a/lib/eth/address.rb
+++ b/lib/eth/address.rb
@@ -12,10 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
-  # The `Eth::Address` class to handle checksummed Ethereum addresses.
+  # The {Eth::Address} class to handle checksummed Ethereum addresses.
   class Address
 
     # Provides a special checksum error if EIP-55 is violated.
@@ -24,7 +24,7 @@ class CheckSumError < StandardError; end
     # The prefixed and checksummed Ethereum address.
     attr_reader :address
 
-    # Constructor of the `Eth::Address` class. Creates a new hex
+    # Constructor of the {Eth::Address} class. Creates a new hex
     # prefixed address.
     #
     # @param address [String] hex string representing an ethereum address.
@@ -38,9 +38,9 @@ def initialize(address)
       end
     end
 
-    # Check that the address is valid.
+    # Checks that the address is valid.
     #
-    # @return [Bool] true if valid address.
+    # @return [Boolean] true if valid address.
     def valid?
       if !matches_any_format?
         false
diff --git a/lib/eth/api.rb b/lib/eth/api.rb
index fe84c31e..2ead069d 100644
--- a/lib/eth/api.rb
+++ b/lib/eth/api.rb
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides the `Eth::Api` module grouping known RPC commands.
diff --git a/lib/eth/chain.rb b/lib/eth/chain.rb
index c171d2d9..818968b7 100644
--- a/lib/eth/chain.rb
+++ b/lib/eth/chain.rb
@@ -12,82 +12,85 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
-  # Encapsulates `Chain` IDs and utilities for EIP-155 compatibility.
-  # ref: https://eips.ethereum.org/EIPS/eip-155
+  # Encapsulates {Eth::Chain} IDs and utilities for EIP-155 compatibility.
+  # Ref: https://eips.ethereum.org/EIPS/eip-155
   module Chain
     extend self
 
     # Provides a special replay protection error if EIP-155 is violated.
     class ReplayProtectionError < StandardError; end
 
-    # Chain ID for Ethereum mainnet
+    # Chain ID for Ethereum mainnet.
     ETHEREUM = 1.freeze
 
-    # Chain ID for Expanse mainnet
+    # Chain ID for Expanse mainnet.
     EXPANSE = 2.freeze
 
-    # Chain ID for Optimistic Ethereum mainnet
+    # Chain ID for Optimistic Ethereum mainnet.
     OPTIMISM = 10.freeze
 
-    # Chain ID for Ethereum Classic mainnet
+    # Chain ID for Ethereum Classic mainnet.
     CLASSIC = 61.freeze
 
-    # Chain ID for POA Network mainnet
+    # Chain ID for POA Network mainnet.
     POA_NET = 99.freeze
 
-    # Chain ID for xDAI mainnet
+    # Chain ID for Gnosis mainnet.
     XDAI = 100.freeze
 
-    # Chain ID for Arbitrum mainnet
+    # Chain ID for Arbitrum mainnet.
     ARBITRUM = 42161.freeze
 
-    # Chain ID for Morden (Ethereum) testnet
+    # Chain ID for Morden (Ethereum) testnet.
     MORDEN = 2.freeze
 
-    # Chain ID for Ropsten testnet
+    # Chain ID for Ropsten testnet.
     ROPSTEN = 3.freeze
 
-    # Chain ID for Rinkeby testnet
+    # Chain ID for Rinkeby testnet.
     RINKEBY = 4.freeze
 
-    # Chain ID for Goerli testnet
+    # Chain ID for Goerli testnet.
     GOERLI = 5.freeze
 
-    # Chain ID for Kotti testnet
+    # Chain ID for Kotti testnet.
     KOTTI = 6.freeze
 
-    # Chain ID for Kovan testnet
+    # Chain ID for Kovan testnet.
     KOVAN = 42.freeze
 
-    # Chain ID for Morden (Classic) testnet
+    # Chain ID for Morden (Classic) testnet.
     MORDEN_CLASSIC = 62.freeze
 
-    # Chain ID for Mordor testnet
+    # Chain ID for Mordor testnet.
     MORDOR = 63.freeze
 
-    # Chain ID for Optimistik Kovan testnet
+    # Chain ID for Optimistik Kovan testnet.
     KOVAN_OPTIMISM = 69.freeze
 
-    # Chain ID for Arbitrum xDAI testnet
+    # Chain ID for Arbitrum xDAI testnet.
     XDAI_ARBITRUM = 200.freeze
 
-    # Chain ID for Optimistic Goerli testnet
+    # Chain ID for Optimistic Goerli testnet.
     GOERLI_OPTIMISM = 420.freeze
 
-    # Chain ID for Arbitrum Rinkeby testnet
+    # Chain ID for Arbitrum Rinkeby testnet.
     RINKEBY_ARBITRUM = 421611.freeze
 
-    # Chain ID for the geth private network preset
+    # Chain ID for Sepolia testnet.
+    SEPOLIA = 11155111.freeze
+
+    # Chain ID for the geth private network preset.
     PRIVATE_GETH = 1337.freeze
 
     # Indicates wether the given `v` indicates a legacy chain value
     # without EIP-155 replay protection.
     #
-    # @param v [Integer] the signature's `v` value
-    # @return [Boolean] true if legacy value
+    # @param v [Integer] the signature's `v` value.
+    # @return [Boolean] true if legacy value.
     def is_legacy?(v)
       [27, 28].include? v
     end
@@ -95,7 +98,7 @@ def is_legacy?(v)
     # Convert a given `v` value to an ECDSA recovery id for the given
     # EIP-155 chain ID.
     #
-    # @param v [Integer] the signature's `v` value
+    # @param v [Integer] the signature's `v` value.
     # @param chain_id [Integer] the chain id the signature was generated on.
     # @return [Integer] the recovery id corresponding to `v`.
     # @raise [ReplayProtectionError] if the given `v` is invalid.
@@ -134,10 +137,10 @@ def to_v(recovery_id, chain_id = nil)
     end
 
     # Converst a `v` value into a chain ID. This does not work for legacy signatures
-    # with v < 36 that do not conform with EIP-155.
+    # with `v < 36` that do not conform with EIP-155.
     #
     # @param v [Integer] the signature's `v` value.
-    # @return [Integer] the chain id as per EIP-155 or nil if there is no replay protection.
+    # @return [Integer] the chain id as per EIP-155 or `nil` if there is no replay protection.
     def to_chain_id(v)
       return nil if v < 36
       chain_id = (v - 35) / 2
diff --git a/lib/eth/client.rb b/lib/eth/client.rb
index 9d281355..941fe814 100644
--- a/lib/eth/client.rb
+++ b/lib/eth/client.rb
@@ -12,10 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
-  # Provides the `Eth::Client` super-class to connect to Ethereum
+  # Provides the {Eth::Client} super-class to connect to Ethereum
   # network's RPC-API endpoints (IPC or HTTP).
   class Client
 
@@ -28,13 +28,13 @@ class Client
     # The connected network's client coinbase.
     attr_accessor :default_account
 
-    # The transaction max priority fee per gas in Wei.
+    # The default transaction max priority fee per gas in Wei.
     attr_accessor :max_priority_fee_per_gas
 
-    # The transaction max fee per gas in Wei.
+    # The default transaction max fee per gas in Wei.
     attr_accessor :max_fee_per_gas
 
-    # The gas limit for the transaction.
+    # The default gas limit for the transaction.
     attr_accessor :gas_limit
 
     # Creates a new RPC-Client, either by providing an HTTP/S host or
@@ -50,7 +50,8 @@ def self.create(host)
       raise ArgumentError, "Unable to detect client type!"
     end
 
-    # Constructor for the Eth::Client super-class.
+    # Constructor for the {Eth::Client} super-class. Should not be used;
+    # use {Client.create} intead.
     def initialize(_)
       @id = 0
       @max_priority_fee_per_gas = 0
@@ -95,7 +96,7 @@ def get_nonce(address)
     # @param destination [Eth::Address] the destination address.
     # @param amount [Integer] the transfer amount in Wei.
     # @param sender_key [Eth::Key] the sender private key.
-    # @param legacy [Bool] enables legacy transactions (pre-EIP-1559).
+    # @param legacy [Boolean] enables legacy transactions (pre-EIP-1559).
     # @return [String] the transaction hash.
     def transfer_and_wait(destination, amount, sender_key = nil, legacy = false)
       wait_for_tx(transfer(destination, amount, sender_key, legacy))
@@ -108,7 +109,7 @@ def transfer_and_wait(destination, amount, sender_key = nil, legacy = false)
     # @param destination [Eth::Address] the destination address.
     # @param amount [Integer] the transfer amount in Wei.
     # @param sender_key [Eth::Key] the sender private key.
-    # @param legacy [Bool] enables legacy transactions (pre-EIP-1559).
+    # @param legacy [Boolean] enables legacy transactions (pre-EIP-1559).
     # @return [String] the transaction hash.
     def transfer(destination, amount, sender_key = nil, legacy = false)
       params = {
@@ -159,7 +160,7 @@ def reset_id
     # Checkes wether a transaction is mined or not.
     #
     # @param hash [String] the transaction hash.
-    # @return [Bool] true if included in a block.
+    # @return [Boolean] true if included in a block.
     def is_mined_tx?(hash)
       mined_tx = eth_get_transaction_by_hash hash
       !mined_tx.nil? && !mined_tx["result"].nil? && !mined_tx["result"]["blockNumber"].nil?
diff --git a/lib/eth/client/http.rb b/lib/eth/client/http.rb
index 4e4dec46..e067d150 100644
--- a/lib/eth/client/http.rb
+++ b/lib/eth/client/http.rb
@@ -14,7 +14,7 @@
 
 require "net/http"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an HTTP/S-RPC client.
@@ -32,7 +32,8 @@ class Client::Http < Client
     # Attribute indicator for SSL.
     attr_reader :ssl
 
-    # Constructor for the HTTP Client.
+    # Constructor for the HTTP Client. Should not be used; use
+    # {Client.create} intead.
     #
     # @param host [String] an URI pointing to an HTTP RPC-API.
     def initialize(host)
diff --git a/lib/eth/client/ipc.rb b/lib/eth/client/ipc.rb
index eb539a37..638d166f 100644
--- a/lib/eth/client/ipc.rb
+++ b/lib/eth/client/ipc.rb
@@ -14,7 +14,7 @@
 
 require "socket"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an IPC-RPC client.
@@ -23,7 +23,8 @@ class Client::Ipc < Client
     # The path of the IPC socket.
     attr_accessor :path
 
-    # Constructor for the IPC Client.
+    # Constructor for the IPC Client. Should not be used; use
+    # {Client.create} intead.
     #
     # @param path [String] an URI pointing to an IPC RPC-API.
     def initialize(path)
diff --git a/lib/eth/constant.rb b/lib/eth/constant.rb
index 00f2767e..7f075adb 100644
--- a/lib/eth/constant.rb
+++ b/lib/eth/constant.rb
@@ -14,7 +14,7 @@
 
 #  -*- encoding : ascii-8bit -*-
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides commonly used constants, such as zero bytes or zero keys.
@@ -50,12 +50,6 @@ module Constant
     # A hash containing only zeros.
     HASH_ZERO = ("\x00" * 32).freeze
 
-    # A private key containing only zeros.
-    PRIVKEY_ZERO = ("\x00" * 32).freeze
-
-    # A private key containing only zeros (hex).
-    PRIVKEY_ZERO_HEX = ("0" * 64).freeze
-
     # The RLP short length limit.
     SHORT_LENGTH_LIMIT = 56.freeze
 
diff --git a/lib/eth/eip712.rb b/lib/eth/eip712.rb
index de1a3d74..d101132d 100644
--- a/lib/eth/eip712.rb
+++ b/lib/eth/eip712.rb
@@ -12,11 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Defines handy tools for encoding typed structured data as per EIP-712.
-  # ref: https://eips.ethereum.org/EIPS/eip-712
+  # Ref: https://eips.ethereum.org/EIPS/eip-712
   module Eip712
     extend self
 
diff --git a/lib/eth/key.rb b/lib/eth/key.rb
index 43238e23..f26ae9b0 100644
--- a/lib/eth/key.rb
+++ b/lib/eth/key.rb
@@ -18,28 +18,28 @@
 require "scrypt"
 require "securerandom"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
-  # The `Eth::Key` class to handle Secp256k1 private/public key-pairs.
+  # The {Eth::Key} class to handle Secp256k1 private/public key-pairs.
   class Key
 
-    # The Eth::Key::Decrypter class to handle PBKDF2-SHA-256 decryption.
+    # The {Eth::Key::Decrypter} class to handle PBKDF2-SHA-256 decryption.
     autoload :Decrypter, "eth/key/decrypter"
 
-    # The Eth::Key::Encrypter class to handle PBKDF2-SHA-256 encryption.
+    # The {Eth::Key::Encrypter} class to handle PBKDF2-SHA-256 encryption.
     autoload :Encrypter, "eth/key/encrypter"
 
-    # The `Secp256k1::PrivateKey` of the `Eth::Key` pair.
+    # The `Secp256k1::PrivateKey` of the {Eth::Key} pair.
     attr_reader :private_key
 
-    # The `Secp256k1::PublicKey` of the `Eth::Key` pair.
+    # The `Secp256k1::PublicKey` of the {Eth::Key} pair.
     attr_reader :public_key
 
-    # Constructor of the `Eth::Key` class. Creates a new random key-pair
+    # Constructor of the {Eth::Key} class. Creates a new random key-pair
     # if no `priv` key is provided.
     #
-    # @param priv [String] binary string of private key data (optional).
+    # @param priv [String] binary string of private key data.
     def initialize(priv: nil)
 
       # Creates a new, randomized libsecp256k1 context.
@@ -63,9 +63,10 @@ def initialize(priv: nil)
     end
 
     # Signs arbitrary data without validation. Should not be used unless really
-    # desired. See also: personal_sign, sign_typed_data.
+    # desired. See also: {Key.personal_sign}, {Key.sign_typed_data}, and
+    # {Signature.recover}.
     #
-    # @param blob [String] that arbitrary data to be signed.
+    # @param blob [Object] that arbitrary data to be signed.
     # @param chain_id [Integer] the chain id the signature should be generated on.
     # @return [String] a hexa-decimal signature.
     def sign(blob, chain_id = nil)
@@ -81,9 +82,11 @@ def sign(blob, chain_id = nil)
       Util.bin_to_hex signature.pack "c*"
     end
 
-    # Prefixes a message with "\x19Ethereum Signed Message:" and signs
+    # Prefixes a message with `\x19Ethereum Signed Message:` and signs
     # it in the common way used by many web3 wallets. Complies with
-    # EIP-191 prefix 0x19 and version byte 0x45 (E).
+    # EIP-191 prefix `0x19` and version byte `0x45` (`E`). See also
+    # {Signature.personal_recover}.
+    # Ref: https://eips.ethereum.org/EIPS/eip-191
     #
     # @param message [String] the message string to be prefixed and signed.
     # @param chain_id [Integer] the chain id the signature should be generated on.
@@ -95,8 +98,10 @@ def personal_sign(message, chain_id = nil)
     end
 
     # Prefixes, hashes, and signes a typed data structure in the common
-    # way used by many web3 wallets. Complies with EIP-191 prefix 0x19
-    # and EIP-712 version byte 0x01. Supports `V3`, `V4`.
+    # way used by many web3 wallets. Complies with EIP-191 prefix `0x19`
+    # and EIP-712 version byte `0x01`. Supports `V3`, `V4`. See also
+    # {Signature.recover_typed_data}.
+    # Ref: https://eips.ethereum.org/EIPS/eip-712
     #
     # @param typed_data [Array] all the data in the typed data structure to be signed.
     # @param chain_id [Integer] the chain id the signature should be generated on.
@@ -114,7 +119,7 @@ def private_hex
     end
 
     # Exports the private key bytes in a wrapper function to maintain
-    # backward-compatibility with older versions of `Eth::Key`.
+    # backward-compatibility with older versions of {Eth::Key}.
     #
     # @return [String] private key as packed byte-string.
     def private_bytes
@@ -138,7 +143,7 @@ def public_hex_compressed
     end
 
     # Exports the uncompressed public key bytes in a wrapper function to
-    # maintain backward-compatibility with older versions of `Eth::Key`.
+    # maintain backward-compatibility with older versions of {Eth::Key}.
     #
     # @return [String] uncompressed public key as packed byte-string.
     def public_bytes
diff --git a/lib/eth/key/decrypter.rb b/lib/eth/key/decrypter.rb
index 0835d1fc..e3afb0d5 100644
--- a/lib/eth/key/decrypter.rb
+++ b/lib/eth/key/decrypter.rb
@@ -12,38 +12,40 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
-  # The Eth::Key::Decrypter class to handle PBKDF2-SHA-256 decryption.
+  # The {Eth::Key::Decrypter} class to handle PBKDF2-SHA-256 decryption.
   class Key::Decrypter
 
     # Provides a specific decrypter error if decryption fails.
     class DecrypterError < StandardError; end
 
-    # Class method `Eth::Key::Decrypter.perform`
+    # Class method {Eth::Key::Decrypter.perform} to perform an keystore
+    # decryption.
     #
-    # @param data [JSON] encryption data including cypherkey
-    # @param password [String] password to decrypt the key
-    # @return [Eth::Key] decrypted key-pair
+    # @param data [JSON] encryption data including cypherkey.
+    # @param password [String] password to decrypt the key.
+    # @return [Eth::Key] decrypted key-pair.
     def self.perform(data, password)
       new(data, password).perform
     end
 
-    # Constructor of the `Eth::Key::Decrypter` class for secret key
-    # encryption.
+    # Constructor of the {Eth::Key::Decrypter} class for secret key
+    # decryption. Should not be used; use {Eth::Key::Decrypter.perform}
+    # instead.
     #
-    # @param data [JSON] encryption data including cypherkey
-    # @param password [String] password to decrypt the key
+    # @param data [JSON] encryption data including cypherkey.
+    # @param password [String] password to decrypt the key.
     def initialize(data, password)
       data = JSON.parse(data) if data.is_a? String
       @data = data
       @password = password
     end
 
-    # Method to decrypt key using password
+    # Method to decrypt key using password.
     #
-    # @return [String] decrypted key
+    # @return [Eth::Key] decrypted key.
     def perform
       derive_key password
       check_macs
diff --git a/lib/eth/key/encrypter.rb b/lib/eth/key/encrypter.rb
index 9c0d5ec9..d9cd6910 100644
--- a/lib/eth/key/encrypter.rb
+++ b/lib/eth/key/encrypter.rb
@@ -12,44 +12,45 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
-  # The Eth::Key::Encrypter class to handle PBKDF2-SHA-256 encryption.
+  # The {Eth::Key::Encrypter} class to handle PBKDF2-SHA-256 encryption.
   class Key::Encrypter
 
     # Provides a specific encrypter error if decryption fails.
     class EncrypterError < StandardError; end
 
-    # Class method `Eth::Key::Encrypter.perform` to performa an key-store
+    # Class method {Eth::Key::Encrypter.perform} to performa an key-store
     # encryption.
     #
-    # @param key [Eth::Key] representing a secret key-pair used for encryption
-    # @param options [Hash] the options to encrypt with
-    # @option options [String] :kdf key derivation function defaults to pbkdf2
-    # @option options [String] :id uuid given to the secret key
-    # @option options [String] :iterations number of iterations for the hash function
-    # @option options [String] :salt passed to PBKDF
-    # @option options [String] :iv 128-bit initialisation vector for the cipher
-    # @option options [Integer] :parallelization parallelization factor for scrypt, defaults to 8
-    # @option options [Integer] :block_size for scrypt, defaults to 1
-    # @return [JSON] formatted with encrypted key (cyphertext) and [other identifying data](https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition#pbkdf2-sha-256)
+    # @param key [Eth::Key] representing a secret key-pair used for encryption.
+    # @param options [Hash] the options to encrypt with.
+    # @option options [String] :kdf key derivation function defaults to pbkdf2.
+    # @option options [String] :id uuid given to the secret key.
+    # @option options [String] :iterations number of iterations for the hash function.
+    # @option options [String] :salt passed to PBKDF.
+    # @option options [String] :iv 128-bit initialisation vector for the cipher.
+    # @option options [Integer] :parallelization parallelization factor for scrypt, defaults to 8.
+    # @option options [Integer] :block_size for scrypt, defaults to 1.
+    # @return [JSON] formatted with encrypted key (cyphertext) and [other identifying data](https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition#pbkdf2-sha-256).
     def self.perform(key, password, options = {})
       new(key, options).perform(password)
     end
 
-    # Constructor of the `Eth::Key::Encrypter` class for secret key
-    # encryption.
+    # Constructor of the {Eth::Key::Encrypter} class for secret key
+    # encryption. Should not be used; use {Eth::Key::Encrypter.perform}
+    # instead.
     #
-    # @param key [Eth::Key] representing a secret key-pair used for encryption
-    # @param options [Hash] the options to encrypt with
-    # @option options [String] :kdf key derivation function defaults to pbkdf2
-    # @option options [String] :id uuid given to the secret key
-    # @option options [String] :iterations number of iterations for the hash function
-    # @option options [String] :salt passed to PBKDF
-    # @option options [String] :iv 128-bit initialisation vector for the cipher
-    # @option options [Integer] :parallelization parallelization factor for scrypt, defaults to 8
-    # @option options [Integer] :block_size for scrypt, defaults to 1
+    # @param key [Eth::Key] representing a secret key-pair used for encryption.
+    # @param options [Hash] the options to encrypt with.
+    # @option options [String] :kdf key derivation function defaults to pbkdf2.
+    # @option options [String] :id uuid given to the secret key.
+    # @option options [String] :iterations number of iterations for the hash function.
+    # @option options [String] :salt passed to PBKDF.
+    # @option options [String] :iv 128-bit initialisation vector for the cipher.
+    # @option options [Integer] :parallelization parallelization factor for scrypt, defaults to 8.
+    # @option options [Integer] :block_size for scrypt, defaults to 1.
     def initialize(key, options = {})
       key = Key.new(priv: key) if key.is_a? String
       @key = key
@@ -65,7 +66,7 @@ def initialize(key, options = {})
     # Encrypt the key with a given password.
     #
     # @param password [String] a secret key used for encryption
-    # @return [String] a json-formatted keystore string.
+    # @return [String] a JSON-formatted keystore string.
     def perform(password)
       derive_key password
       encrypt
diff --git a/lib/eth/rlp.rb b/lib/eth/rlp.rb
index a1b18198..a59c385d 100644
--- a/lib/eth/rlp.rb
+++ b/lib/eth/rlp.rb
@@ -19,14 +19,14 @@
 require "eth/rlp/sedes"
 require "eth/util"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an recursive-length prefix (RLP) encoder and decoder.
   module Rlp
     extend self
 
-    # The Rlp module exposes a variety of exceptions grouped as RlpException.
+    # The Rlp module exposes a variety of exceptions grouped as {RlpException}.
     class RlpException < StandardError; end
 
     # An error-type to point out RLP-encoding errors.
@@ -41,10 +41,10 @@ class SerializationError < RlpException; end
     # An error-type to point out RLP-type serialization errors.
     class DeserializationError < RlpException; end
 
-    # A wrapper to represent already RLP encoded data.
+    # A wrapper to represent already RLP-encoded data.
     class Data < String; end
 
-    # Performes an Eth::Rlp::Encoder on any ruby object.
+    # Performes an {Eth::Rlp::Encoder} on any ruby object.
     #
     # @param obj [Object] any ruby object.
     # @return [String] a packed, RLP-encoded item.
@@ -52,7 +52,7 @@ def encode(obj)
       Rlp::Encoder.perform obj
     end
 
-    # Performes an Eth::Rlp::Decoder on any RLP-encoded item.
+    # Performes an {Eth::Rlp::Decoder} on any RLP-encoded item.
     #
     # @param rlp [String] a packed, RLP-encoded item.
     # @return [Object] a decoded ruby object.
diff --git a/lib/eth/rlp/decoder.rb b/lib/eth/rlp/decoder.rb
index 5dc901b6..6cb3e834 100644
--- a/lib/eth/rlp/decoder.rb
+++ b/lib/eth/rlp/decoder.rb
@@ -14,7 +14,7 @@
 
 # -*- encoding : ascii-8bit -*-
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an recursive-length prefix (RLP) encoder and decoder.
@@ -30,7 +30,6 @@ module Decoder
       # @return [Object] the decoded and maybe deserialized object.
       # @raise [Eth::Rlp::DecodingError] if the input string does not end after
       #     the root item.
-      # @raise [Eht::Rlp::DeserializationError] if the deserialization fails.
       def perform(rlp)
         rlp = Util.hex_to_bin rlp if Util.is_hex? rlp
         rlp = Util.str_to_bytes rlp
diff --git a/lib/eth/rlp/encoder.rb b/lib/eth/rlp/encoder.rb
index 0d6385e6..e79dfabd 100644
--- a/lib/eth/rlp/encoder.rb
+++ b/lib/eth/rlp/encoder.rb
@@ -14,7 +14,7 @@
 
 # -*- encoding : ascii-8bit -*-
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an recursive-length prefix (RLP) encoder and decoder.
diff --git a/lib/eth/rlp/sedes.rb b/lib/eth/rlp/sedes.rb
index 4503e3a9..6e5d00ae 100644
--- a/lib/eth/rlp/sedes.rb
+++ b/lib/eth/rlp/sedes.rb
@@ -18,7 +18,7 @@
 require "eth/rlp/sedes/binary"
 require "eth/rlp/sedes/list"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an recursive-length prefix (RLP) encoder and decoder.
@@ -27,13 +27,13 @@ module Rlp
     # Provides serializable and deserializable types (SeDes).
     module Sedes
 
-      # Provides a singleton Eth::Rlp::Sedes class to infer objects and types.
+      # Provides a singleton {Eth::Rlp::Sedes} class to infer objects and types.
       class << self
 
         # Tries to find a sedes objects suitable for a given Ruby object.
         #
-        # The sedes objects considered are `obj`'s class, `big_endian_int` and
-        # `binary`. If `obj` is a list, an `Eth::Rlp::Sedes::List` will be
+        # The sedes objects considered are `obj`'s class, {big_endian_int} and
+        # {binary}. If `obj` is a list, an {Eth::Rlp::Sedes::List} will be
         # constructed recursively.
         #
         # @param obj [Object] the Ruby object for which to find a sedes object.
diff --git a/lib/eth/rlp/sedes/big_endian_int.rb b/lib/eth/rlp/sedes/big_endian_int.rb
index 93e22184..06c888d3 100644
--- a/lib/eth/rlp/sedes/big_endian_int.rb
+++ b/lib/eth/rlp/sedes/big_endian_int.rb
@@ -14,7 +14,7 @@
 
 # -*- encoding : ascii-8bit -*-
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an recursive-length prefix (RLP) encoder and decoder.
diff --git a/lib/eth/rlp/sedes/binary.rb b/lib/eth/rlp/sedes/binary.rb
index b2ad2ee8..1f751b29 100644
--- a/lib/eth/rlp/sedes/binary.rb
+++ b/lib/eth/rlp/sedes/binary.rb
@@ -14,7 +14,7 @@
 
 # -*- encoding : ascii-8bit -*-
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an recursive-length prefix (RLP) encoder and decoder.
diff --git a/lib/eth/rlp/sedes/list.rb b/lib/eth/rlp/sedes/list.rb
index 7ca85d41..b999a06e 100644
--- a/lib/eth/rlp/sedes/list.rb
+++ b/lib/eth/rlp/sedes/list.rb
@@ -14,7 +14,7 @@
 
 # -*- encoding : ascii-8bit -*-
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides an recursive-length prefix (RLP) encoder and decoder.
diff --git a/lib/eth/signature.rb b/lib/eth/signature.rb
index bd324fa3..3ecb243a 100644
--- a/lib/eth/signature.rb
+++ b/lib/eth/signature.rb
@@ -14,7 +14,7 @@
 
 require "rbsecp256k1"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Defines handy tools for verifying and recovering signatures.
@@ -30,21 +30,22 @@ class SignatureError < StandardError; end
     # EIP-712 version byte 0x01
     EIP712_VERSION_BYTE = "\x01".freeze
 
-    # Prefix message as per EIP-191 with 0x19 to ensure the data is not
+    # Prefix message as per EIP-191 with `0x19` to ensure the data is not
     # valid RLP and thus not mistaken for a transaction.
-    # EIP-191 Version byte: 0x45 (E)
-    # ref: https://eips.ethereum.org/EIPS/eip-191
+    # EIP-191 Version byte: `0x45` (`E`)
+    # Ref: https://eips.ethereum.org/EIPS/eip-191
     #
     # @param message [String] the message string to be prefixed.
-    # @return [String] an EIP-191 prefixed string
+    # @return [String] an EIP-191 prefixed string.
     def prefix_message(message)
       "#{EIP191_PREFIX_BYTE}Ethereum Signed Message:\n#{message.size}#{message}"
     end
 
-    # Dissects a signature blob of 65 bytes into its r, s, and v values.
+    # Dissects a signature blob of 65+ bytes into its `r`, `s`, and `v`
+    # values.
     #
-    # @param signature [String] a Secp256k1 signature.
-    # @return [String, String, String] the r, s, and v values.
+    # @param signature [String] a concatenated Secp256k1 signature string.
+    # @return [String, String, String] the `r`, `s`, and `v` values.
     # @raise [SignatureError] if signature is of unknown size.
     def dissect(signature)
       signature = Util.bin_to_hex signature unless Util.is_hex? signature
@@ -79,6 +80,7 @@ def recover(blob, signature, chain_id = Chain::ETHEREUM)
 
     # Recovers a public key from a prefixed, personal message and
     # a signature on a given chain. (EIP-191)
+    # Ref: https://eips.ethereum.org/EIPS/eip-191
     #
     # @param message [String] the message string.
     # @param signature [String] the hex string containing the signature.
@@ -92,6 +94,7 @@ def personal_recover(message, signature, chain_id = Chain::ETHEREUM)
 
     # Recovers a public key from a typed data structure and a signature
     # on a given chain. (EIP-712)
+    # Ref: https://eips.ethereum.org/EIPS/eip-712
     #
     # @param typed_data [Array] all the data in the typed data structure to be recovered.
     # @param signature [String] the hex string containing the signature.
diff --git a/lib/eth/tx.rb b/lib/eth/tx.rb
index ab23380b..130a0231 100644
--- a/lib/eth/tx.rb
+++ b/lib/eth/tx.rb
@@ -20,14 +20,14 @@
 require "eth/tx/legacy"
 require "eth/unit"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides the `Tx` module supporting various transaction types.
   module Tx
     extend self
 
-    # Provides a special transactoin error if transaction type is unknown.
+    # Provides a special transaction error if transaction type is unknown.
     class TransactionTypeError < TypeError; end
 
     # Provides an decoder error if transaction cannot be decoded.
diff --git a/lib/eth/tx/eip1559.rb b/lib/eth/tx/eip1559.rb
index e2e01f06..ba6b16c6 100644
--- a/lib/eth/tx/eip1559.rb
+++ b/lib/eth/tx/eip1559.rb
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides the `Tx` module supporting various transaction types.
@@ -20,9 +20,11 @@ module Tx
 
     # Provides support for EIP-1559 transactions utilizing EIP-2718
     # types and envelopes.
+    # Ref: https://eips.ethereum.org/EIPS/eip-1559
     class Eip1559
 
       # The EIP-155 Chain ID.
+      # Ref: https://eips.ethereum.org/EIPS/eip-155
       attr_reader :chain_id
 
       # The transaction nonce provided by the signer.
@@ -47,6 +49,7 @@ class Eip1559
       attr_reader :payload
 
       # An optional EIP-2930 access list.
+      # Ref: https://eips.ethereum.org/EIPS/eip-2930
       attr_reader :access_list
 
       # The signature's y-parity byte (not v).
@@ -66,6 +69,7 @@ class Eip1559
 
       # Create a type-2 (EIP-1559) transaction payload object that
       # can be prepared for envelope, signature and broadcast.
+      # Ref: https://eips.ethereum.org/EIPS/eip-1559
       #
       # @param params [Hash] all necessary transaction fields.
       # @option params [Integer] :chain_id the chain ID.
@@ -78,6 +82,7 @@ class Eip1559
       # @option params [Integer] :value the transaction value.
       # @option params [String] :data the transaction data payload.
       # @option params [Array] :access_list an optional access list.
+      # @raise [ParameterError] if gas limit is too low.
       def initialize(params)
         fields = { recovery_id: nil, r: 0, s: 0 }.merge params
 
@@ -122,7 +127,7 @@ def initialize(params)
       # Overloads the constructor for decoding raw transactions and creating unsigned copies.
       konstructor :decode, :unsigned_copy
 
-      # Decodes a raw transaction hex into an Eth::Tx::Eip1559
+      # Decodes a raw transaction hex into an {Eth::Tx::Eip1559}
       # transaction object.
       #
       # @param hex [String] the raw transaction hex-string.
@@ -222,8 +227,8 @@ def unsigned_copy(tx)
       #
       # @param key [Eth::Key] the key-pair to use for signing.
       # @return [String] a transaction hash.
-      # @raise [SignatureError] if transaction is already signed.
-      # @raise [SignatureError] if sender address does not match signing key.
+      # @raise [Signature::SignatureError] if transaction is already signed.
+      # @raise [Signature::SignatureError] if sender address does not match signing key.
       def sign(key)
         if Tx.is_signed? self
           raise Signature::SignatureError, "Transaction is already signed!"
@@ -250,7 +255,7 @@ def sign(key)
       # with an EIP-1559 type prefix.
       #
       # @return [String] a raw, RLP-encoded EIP-1559 type transaction object.
-      # @raise [SignatureError] if the transaction is not yet signed.
+      # @raise [Signature::SignatureError] if the transaction is not yet signed.
       def encoded
         unless Tx.is_signed? self
           raise Signature::SignatureError, "Transaction is not signed!"
diff --git a/lib/eth/tx/eip2930.rb b/lib/eth/tx/eip2930.rb
index f14bf101..f0675032 100644
--- a/lib/eth/tx/eip2930.rb
+++ b/lib/eth/tx/eip2930.rb
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides the `Tx` module supporting various transaction types.
@@ -20,9 +20,11 @@ module Tx
 
     # Provides legacy support for transactions on blockchains that do not
     # implement EIP-1559 but still want to utilize EIP-2718 envelopes.
+    # Ref: https://eips.ethereum.org/EIPS/eip-2930
     class Eip2930
 
       # The EIP-155 Chain ID.
+      # Ref: https://eips.ethereum.org/EIPS/eip-155
       attr_reader :chain_id
 
       # The transaction nonce provided by the signer.
@@ -44,9 +46,10 @@ class Eip2930
       attr_reader :payload
 
       # An optional EIP-2930 access list.
+      # Ref: https://eips.ethereum.org/EIPS/eip-2930
       attr_reader :access_list
 
-      # The signature's y-parity byte (not v).
+      # The signature's `y`-parity byte (not `v`).
       attr_reader :signature_y_parity
 
       # The signature `r` value.
@@ -64,6 +67,7 @@ class Eip2930
       # Create a legacy type-1 (EIP-2930) transaction payload object that
       # can be prepared for envelope, signature and broadcast. Should not
       # be used unless there is no EIP-1559 support.
+      # Ref: https://eips.ethereum.org/EIPS/eip-2930
       #
       #
       # @param params [Hash] all necessary transaction fields.
@@ -76,6 +80,7 @@ class Eip2930
       # @option params [Integer] :value the transaction value.
       # @option params [String] :data the transaction data payload.
       # @option params [Array] :access_list an optional access list.
+      # @raise [ParameterError] if gas limit is too low.
       def initialize(params)
         fields = { recovery_id: nil, r: 0, s: 0 }.merge params
 
@@ -119,7 +124,7 @@ def initialize(params)
       # Overloads the constructor for decoding raw transactions and creating unsigned copies.
       konstructor :decode, :unsigned_copy
 
-      # Decodes a raw transaction hex into an Eth::Tx::Eip2930
+      # Decodes a raw transaction hex into an {Eth::Tx::Eip2930}
       # transaction object.
       #
       # @param hex [String] the raw transaction hex-string.
@@ -216,8 +221,8 @@ def unsigned_copy(tx)
       #
       # @param key [Eth::Key] the key-pair to use for signing.
       # @return [String] a transaction hash.
-      # @raise [SignatureError] if transaction is already signed.
-      # @raise [SignatureError] if sender address does not match signing key.
+      # @raise [Signature::SignatureError] if transaction is already signed.
+      # @raise [Signature::SignatureError] if sender address does not match signing key.
       def sign(key)
         if Tx.is_signed? self
           raise Signature::SignatureError, "Transaction is already signed!"
@@ -244,7 +249,7 @@ def sign(key)
       # with an EIP-2930 type prefix.
       #
       # @return [String] a raw, RLP-encoded EIP-2930 type transaction object.
-      # @raise [SignatureError] if the transaction is not yet signed.
+      # @raise [Signature::SignatureError] if the transaction is not yet signed.
       def encoded
         unless Tx.is_signed? self
           raise Signature::SignatureError, "Transaction is not signed!"
diff --git a/lib/eth/tx/legacy.rb b/lib/eth/tx/legacy.rb
index 74e007cc..a391cb72 100644
--- a/lib/eth/tx/legacy.rb
+++ b/lib/eth/tx/legacy.rb
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides the `Tx` module supporting various transaction types.
@@ -50,6 +50,7 @@ class Legacy
       attr_reader :signature_s
 
       # The EIP-155 chain ID field.
+      # Ref: https://eips.ethereum.org/EIPS/eip-155
       attr_reader :chain_id
 
       # The sender address.
@@ -71,6 +72,7 @@ class Legacy
       # @option params [Integer] :value the transaction value.
       # @option params [String] :data the transaction data payload.
       # @param chain_id [Integer] the EIP-155 Chain ID.
+      # @raise [ParameterError] if gas limit is too low.
       def initialize(params, chain_id = Chain::ETHEREUM)
         fields = { v: chain_id, r: 0, s: 0 }.merge params
 
@@ -111,7 +113,7 @@ def initialize(params, chain_id = Chain::ETHEREUM)
       # overloads the constructor for decoding raw transactions and creating unsigned copies
       konstructor :decode, :unsigned_copy
 
-      # Decodes a raw transaction hex into an Eth::Tx::Legacy
+      # Decodes a raw transaction hex into an {Eth::Tx::Legacy}
       # transaction object.
       #
       # @param hex [String] the raw transaction hex-string.
@@ -199,8 +201,8 @@ def unsigned_copy(tx)
       #
       # @param key [Eth::Key] the key-pair to use for signing.
       # @return [String] a transaction hash.
-      # @raise [SignatureError] if transaction is already signed.
-      # @raise [SignatureError] if sender address does not match signing key.
+      # @raise [Signature::SignatureError] if transaction is already signed.
+      # @raise [Signature::SignatureError] if sender address does not match signing key.
       def sign(key)
         if Tx.is_signed? self
           raise Signature::SignatureError, "Transaction is already signed!"
@@ -225,7 +227,7 @@ def sign(key)
       # Encodes a raw transaction object.
       #
       # @return [String] a raw, RLP-encoded legacy transaction.
-      # @raise [SignatureError] if the transaction is not yet signed.
+      # @raise [Signature::SignatureError] if the transaction is not yet signed.
       def encoded
         unless Tx.is_signed? self
           raise Signature::SignatureError, "Transaction is not signed!"
diff --git a/lib/eth/unit.rb b/lib/eth/unit.rb
index 5506f515..84b0fc6f 100644
--- a/lib/eth/unit.rb
+++ b/lib/eth/unit.rb
@@ -14,7 +14,7 @@
 
 require "bigdecimal"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
   # Provides constants for common Ethereum units.
diff --git a/lib/eth/util.rb b/lib/eth/util.rb
index a8144892..a4d4f648 100644
--- a/lib/eth/util.rb
+++ b/lib/eth/util.rb
@@ -14,10 +14,10 @@
 
 require "digest/keccak"
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
-  # Defines handy tools for the `Eth` gem for convenience.
+  # Defines handy tools for the {Eth} gem for convenience.
   module Util
     extend self
 
@@ -92,7 +92,7 @@ def bin_to_prefixed_hex(bin)
     # Checks if a string is hex-adecimal.
     #
     # @param str [String] a string to be checked.
-    # @return [String] a match if true; nil if not.
+    # @return [String] a match if true; `nil` if not.
     def is_hex?(str)
       return false unless str.is_a? String
       str = remove_hex_prefix str
@@ -102,7 +102,7 @@ def is_hex?(str)
     # Checks if a string is prefixed with `0x`.
     #
     # @param hex [String] a string to be checked.
-    # @return [String] a match if true; nil if not.
+    # @return [String] a match if true; `nil` if not.
     def is_prefixed?(hex)
       hex.match /\A0x/
     end
@@ -110,8 +110,8 @@ def is_prefixed?(hex)
     # Serializes an unsigned integer to big endian.
     #
     # @param num [Integer] unsigned integer to be serialized.
-    # return [String] serialized big endian integer string.
-    # raises [ArgumentError] if unsigned integer is out of bounds.
+    # @return [String] serialized big endian integer string.
+    # @raise [ArgumentError] if unsigned integer is out of bounds.
     def serialize_int_to_big_endian(num)
       num = num.to_i(16) if is_hex? num
       unless num.is_a? Integer and num >= 0 and num <= Constant::UINT_MAX
@@ -123,7 +123,7 @@ def serialize_int_to_big_endian(num)
     # Converts an integer to big endian.
     #
     # @param num [Integer] integer to be converted.
-    # return [String] packed, big-endian integer string.
+    # @return [String] packed, big-endian integer string.
     def int_to_big_endian(num)
       hex = num.to_s(16) unless is_hex? num
       hex = "0#{hex}" if hex.size.odd?
@@ -141,7 +141,7 @@ def deserialize_big_endian_to_int(str)
     # Converts a big endian to an interger.
     #
     # @param str [String] big endian to be converted.
-    # return [Integer] an unpacked integer number.
+    # @return [Integer] an unpacked integer number.
     def big_endian_to_int(str)
       str.unpack("H*").first.to_i(16)
     end
@@ -149,7 +149,7 @@ def big_endian_to_int(str)
     # Converts a binary string to bytes.
     #
     # @param str [String] binary string to be converted.
-    # return [Object] the string bytes.
+    # @return [Object] the string bytes.
     def str_to_bytes(str)
       is_bytes?(str) ? str : str.b
     end
@@ -157,7 +157,7 @@ def str_to_bytes(str)
     # Converts bytes to a binary string.
     #
     # @param bin [Object] bytes to be converted.
-    # return [String] a packed binary string.
+    # @return [String] a packed binary string.
     def bytes_to_str(bin)
       bin.unpack("U*").pack("U*")
     end
diff --git a/lib/eth/version.rb b/lib/eth/version.rb
index 1d3ab8af..dcd80989 100644
--- a/lib/eth/version.rb
+++ b/lib/eth/version.rb
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Provides the `Eth` module.
+# Provides the {Eth} module.
 module Eth
 
-  # Defines the version of the `Eth` module.
+  # Defines the version of the {Eth} module.
   VERSION = "0.5.1".freeze
 end
diff --git a/spec/eth/chain_spec.rb b/spec/eth/chain_spec.rb
index 53b3d45b..61ddecf6 100644
--- a/spec/eth/chain_spec.rb
+++ b/spec/eth/chain_spec.rb
@@ -25,6 +25,7 @@
       expect(Chain::XDAI_ARBITRUM).to eq 200
       expect(Chain::GOERLI_OPTIMISM).to eq 420
       expect(Chain::RINKEBY_ARBITRUM).to eq 421611
+      expect(Chain::SEPOLIA).to eq 11155111
 
       # Chain IDs for selected private networks
       expect(Chain::PRIVATE_GETH).to eq 1337
diff --git a/spec/eth/constant_spec.rb b/spec/eth/constant_spec.rb
index 7f4207a2..241b0ec7 100644
--- a/spec/eth/constant_spec.rb
+++ b/spec/eth/constant_spec.rb
@@ -15,8 +15,6 @@
       expect(Constant::INT_MAX).to eq 57896044618658097711785492504343953926634992332820282019728792003956564819967
       expect(Constant::INT_MIN).to eq -57896044618658097711785492504343953926634992332820282019728792003956564819968
       expect(Constant::HASH_ZERO).to eq "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
-      expect(Constant::PRIVKEY_ZERO).to eq "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
-      expect(Constant::PRIVKEY_ZERO_HEX).to eq "0000000000000000000000000000000000000000000000000000000000000000"
       expect(Constant::SHORT_LENGTH_LIMIT).to eq 56
       expect(Constant::LONG_LENGTH_LIMIT).to eq 18446744073709551616
       expect(Constant::PRIMITIVE_PREFIX_OFFSET).to eq 128