diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,12 @@
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 0.6.0
+### Changed
+- Force initialization of addresses through smart constructor.
+- Assume addresses are always valid when instantiated in code.
+- Allow to provide unwrapped private keys to transaction signing functions.
+
 ## 0.5.2
 ### Changed
 - Make dependencies more specific.
diff --git a/haskoin-core.cabal b/haskoin-core.cabal
--- a/haskoin-core.cabal
+++ b/haskoin-core.cabal
@@ -2,10 +2,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: ad1cee7927edceba3d2f91465b04efc75dd1e49429d6150b29670ba6f5dc9722
+-- hash: 60cf3a9fd398cb3bffeaa6d67b67e5bf4d56163b98c4137d7738ace0286ec13f
 
 name:           haskoin-core
-version:        0.5.2
+version:        0.6.0
 synopsis:       Bitcoin & Bitcoin Cash library for Haskell
 description:    Haskoin Core is a complete Bitcoin and Bitcoin Cash library of functions and data types for Haskell developers.
 category:       Bitcoin, Finance, Network
diff --git a/src/Haskoin.hs b/src/Haskoin.hs
--- a/src/Haskoin.hs
+++ b/src/Haskoin.hs
@@ -1,13 +1,42 @@
+{-|
+Module      : Haskoin
+Description : Bitcoin (BTC/BCH) Libraries for Haskell
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+This module exports almost all of Haskoin Core, excluding only a few highly
+specialized address and block-related functions.
+-}
 module Haskoin
-    ( module X
+    ( -- * Address (Base58, Bech32, CashAddr)
+      module Address
+      -- * Network Messages
+    , module Network
+      -- * Network Constants
+    , module Constants
+      -- * Blocks
+    , module Block
+      -- * Transactions
+    , module Transaction
+      -- * Scripts
+    , module Script
+      -- * Cryptographic Keys
+    , module Keys
+      -- * Cryptographic Primitives
+    , module Crypto
+      -- * Various Utilities
+    , module Util
     ) where
 
-import           Network.Haskoin.Address     as X
-import           Network.Haskoin.Block       as X
-import           Network.Haskoin.Constants   as X
-import           Network.Haskoin.Crypto      as X
-import           Network.Haskoin.Keys        as X
-import           Network.Haskoin.Network     as X
-import           Network.Haskoin.Script      as X
-import           Network.Haskoin.Transaction as X
-import           Network.Haskoin.Util        as X
+import           Network.Haskoin.Address     as Address
+import           Network.Haskoin.Block       as Block
+import           Network.Haskoin.Constants   as Constants
+import           Network.Haskoin.Crypto      as Crypto
+import           Network.Haskoin.Keys        as Keys
+import           Network.Haskoin.Network     as Network
+import           Network.Haskoin.Script      as Script
+import           Network.Haskoin.Transaction as Transaction
+import           Network.Haskoin.Util        as Util
diff --git a/src/Network/Haskoin/Address.hs b/src/Network/Haskoin/Address.hs
--- a/src/Network/Haskoin/Address.hs
+++ b/src/Network/Haskoin/Address.hs
@@ -1,12 +1,34 @@
 {-# LANGUAGE DeriveGeneric     #-}
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Address
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Base58, CashAddr, Bech32 address and WIF private key serialization support.
+-}
 module Network.Haskoin.Address
-    ( Address(..)
+    ( Address
+    , getAddrHash160
+    , getAddrHash256
+    , getAddrNet
+    , isPubKeyAddress
+    , isScriptAddress
+    , isWitnessPubKeyAddress
+    , isWitnessScriptAddress
     , addrToString
     , stringToAddr
     , addrFromJSON
     , pubKeyAddr
+    , pubKeyWitnessAddr
+    , p2pkhAddr
+    , p2wpkhAddr
+    , p2shAddr
+    , p2wshAddr
       -- * Private Key Wallet Import Format (WIF)
     , fromWif
     , toWif
@@ -19,6 +41,7 @@
 import           Data.Aeson.Types
 import qualified Data.ByteString                  as B
 import           Data.Function
+import           Data.Hashable
 import           Data.List
 import           Data.Maybe
 import           Data.Serialize                   as S
@@ -38,18 +61,40 @@
 data Address
     -- | pay to public key hash (regular)
     = PubKeyAddress { getAddrHash160 :: !Hash160
-                    , getAddrNet     :: !Network }
+                        -- ^ RIPEMD160 hash of public key's SHA256 hash
+                    , getAddrNet :: !Network
+                        -- ^ address network
+                     }
     -- | pay to script hash
     | ScriptAddress { getAddrHash160 :: !Hash160
-                    , getAddrNet     :: !Network }
+                        -- ^ RIPEMD160 hash of script's SHA256 hash
+                    , getAddrNet :: !Network
+                        -- ^ address network
+                     }
     -- | pay to witness public key hash
     | WitnessPubKeyAddress { getAddrHash160 :: !Hash160
-                           , getAddrNet     :: !Network }
+                               -- ^ RIPEMD160 hash of public key's SHA256 hash
+                           , getAddrNet :: !Network
+                               -- ^ address network
+                           }
     -- | pay to witness script hash
     | WitnessScriptAddress { getAddrHash256 :: !Hash256
-                           , getAddrNet     :: !Network }
+                               -- ^ HASH256 hash of script
+                           , getAddrNet :: !Network
+                               -- ^ address network
+                           }
     deriving (Eq, G.Generic)
 
+instance Hashable Address where
+    hashWithSalt i (PubKeyAddress h _)        = i `hashWithSalt` h
+    hashWithSalt i (ScriptAddress h _)        = i `hashWithSalt` h
+    hashWithSalt i (WitnessPubKeyAddress h _) = i `hashWithSalt` h
+    hashWithSalt i (WitnessScriptAddress h _) = i `hashWithSalt` h
+    hash (PubKeyAddress h _)        = hash h
+    hash (ScriptAddress h _)        = hash h
+    hash (WitnessPubKeyAddress h _) = hash h
+    hash (WitnessScriptAddress h _) = hash h
+
 instance Ord Address where
     compare = compare `on` f
       where
@@ -60,6 +105,27 @@
 
 instance NFData Address
 
+-- | 'Address' pays to a public key hash.
+isPubKeyAddress :: Address -> Bool
+isPubKeyAddress PubKeyAddress {} = True
+isPubKeyAddress _                = False
+
+-- | 'Address' pays to a script hash.
+isScriptAddress :: Address -> Bool
+isScriptAddress ScriptAddress {} = True
+isScriptAddress _                = False
+
+-- | 'Address' pays to a witness public key hash. Only valid for SegWit
+-- networks.
+isWitnessPubKeyAddress :: Address -> Bool
+isWitnessPubKeyAddress WitnessPubKeyAddress {} = True
+isWitnessPubKeyAddress _                       = False
+
+-- | 'Address' pays to a witness script hash. Only valid for SegWit networks.
+isWitnessScriptAddress :: Address -> Bool
+isWitnessScriptAddress WitnessScriptAddress {} = True
+isWitnessScriptAddress _                       = False
+
 -- | Deserializer for binary 'Base58' addresses.
 base58get :: Network -> Get Address
 base58get net = do
@@ -83,10 +149,7 @@
 base58put _ = error "Cannot serialize this address as Base58"
 
 instance Show Address where
-    showsPrec _ a =
-        case addrToString a of
-            Just s  -> shows s
-            Nothing -> fail "Cannot show this transaction"
+    showsPrec _ a = shows (addrToString a)
 
 instance Read Address where
     readPrec = do
@@ -96,7 +159,7 @@
             foldl' (\a n -> a <|> stringToAddr n bs) Nothing allNets
 
 instance ToJSON Address where
-    toJSON = A.String . fromMaybe (error "Could not encode address") . addrToString
+    toJSON = A.String . addrToString
 
 -- | JSON parsing for Bitcoin addresses. Works with 'Base58', 'CashAddr' and
 -- 'Bech32'.
@@ -109,22 +172,33 @@
 
 -- | Convert address to human-readable string. Uses 'Base58', 'Bech32', or
 -- 'CashAddr' depending on network.
-addrToString :: Address -> Maybe Text
+addrToString :: Address -> Text
 addrToString a@PubKeyAddress {getAddrHash160 = h, getAddrNet = net}
     | isNothing (getCashAddrPrefix net) =
-        return $ encodeBase58Check $ runPut $ base58put a
-    | otherwise = cashAddrEncode net 0 (S.encode h)
+        encodeBase58Check $ runPut $ base58put a
+    | otherwise =
+        fromMaybe (error "Colud not encode a CashAddr") $
+        cashAddrEncode net 0 (S.encode h)
+
 addrToString a@ScriptAddress {getAddrHash160 = h, getAddrNet = net}
     | isNothing (getCashAddrPrefix net) =
-        return $ encodeBase58Check $ runPut $ base58put a
-    | otherwise = cashAddrEncode net 1 (S.encode h)
-addrToString WitnessPubKeyAddress {getAddrHash160 = h, getAddrNet = net} = do
-    hrp <- getBech32Prefix net
-    segwitEncode hrp 0 (B.unpack (S.encode h))
-addrToString WitnessScriptAddress {getAddrHash256 = h, getAddrNet = net} = do
-    hrp <- getBech32Prefix net
-    segwitEncode hrp 0 (B.unpack (S.encode h))
+        encodeBase58Check $ runPut $ base58put a
+    | otherwise =
+        fromMaybe (error "Could not encode a CashAddr") $
+        cashAddrEncode net 1 (S.encode h)
 
+addrToString WitnessPubKeyAddress {getAddrHash160 = h, getAddrNet = net} =
+    let mt = do
+            hrp <- getBech32Prefix net
+            segwitEncode hrp 0 (B.unpack (S.encode h))
+     in fromMaybe (error "Could not encode a Bech32 address") mt
+
+addrToString WitnessScriptAddress {getAddrHash256 = h, getAddrNet = net} =
+    let mt = do
+            hrp <- getBech32Prefix net
+            segwitEncode hrp 0 (B.unpack (S.encode h))
+     in fromMaybe (error "Could not encode a Bech32 address") mt
+
 -- | Parse 'Base58', 'Bech32' or 'CashAddr' address, depending on network.
 stringToAddr :: Network -> Text -> Maybe Address
 stringToAddr net bs = cash <|> segwit <|> b58
@@ -155,6 +229,32 @@
 -- | Obtain a P2PKH address from a public key.
 pubKeyAddr :: Network -> PubKeyI -> Address
 pubKeyAddr net k = PubKeyAddress (addressHash (S.encode k)) net
+
+-- | Obtain a P2PKH address from a 'Hash160'.
+p2pkhAddr :: Network -> Hash160 -> Address
+p2pkhAddr net h = PubKeyAddress h net
+
+-- | Obtain a P2WPKH address from a public key. Only on SegWit networks.
+pubKeyWitnessAddr :: Network -> PubKeyI -> Maybe Address
+pubKeyWitnessAddr net k
+    | getSegWit net = Just $ WitnessPubKeyAddress (addressHash (S.encode k)) net
+    | otherwise = Nothing
+
+-- | Obtain a P2WPKH address from a 'Hash160'.
+p2wpkhAddr :: Network -> Hash160 -> Maybe Address
+p2wpkhAddr net h
+    | getSegWit net = Just $ WitnessPubKeyAddress h net
+    | otherwise = Nothing
+
+-- | Obtain a P2SH address from a 'Hash160'.
+p2shAddr :: Network -> Hash160 -> Address
+p2shAddr net h = ScriptAddress h net
+
+-- | Obtain a P2WSH address from a 'Hash256'
+p2wshAddr :: Network -> Hash256 -> Maybe Address
+p2wshAddr net h
+    | getSegWit net = Just $ WitnessScriptAddress h net
+    | otherwise = Nothing
 
 -- | Decode private key from WIF (wallet import format) string.
 fromWif :: Network -> Base58 -> Maybe SecKeyI
diff --git a/src/Network/Haskoin/Address/Base58.hs b/src/Network/Haskoin/Address/Base58.hs
--- a/src/Network/Haskoin/Address/Base58.hs
+++ b/src/Network/Haskoin/Address/Base58.hs
@@ -1,4 +1,15 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Address.Base58
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Support for legacy 'Base58' addresses. Superseded by Bech32 for Bitcoin SegWit
+(BTC) and CashAddr for Bitcoin Cash (BCH).
+-}
 module Network.Haskoin.Address.Base58
     ( Base58
     , encodeBase58
diff --git a/src/Network/Haskoin/Address/Bech32.hs b/src/Network/Haskoin/Address/Bech32.hs
--- a/src/Network/Haskoin/Address/Bech32.hs
+++ b/src/Network/Haskoin/Address/Bech32.hs
@@ -1,6 +1,15 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Address.Base58
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 
-{- Copied from reference implementation contributed by Marko Bencun -}
+Support for Bitcoin SegWit (BTC) Bech32 addresses. This module is a modified
+version of Marko Bencun's reference implementation.
+-}
 module Network.Haskoin.Address.Bech32
     ( HRP
     , Bech32
diff --git a/src/Network/Haskoin/Address/CashAddr.hs b/src/Network/Haskoin/Address/CashAddr.hs
--- a/src/Network/Haskoin/Address/CashAddr.hs
+++ b/src/Network/Haskoin/Address/CashAddr.hs
@@ -1,4 +1,14 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Address.CashAddr
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Support for Bitcoin Cash (BCH) CashAddr format.
+-}
 module Network.Haskoin.Address.CashAddr
     ( CashPrefix
     , CashVersion
diff --git a/src/Network/Haskoin/Block.hs b/src/Network/Haskoin/Block.hs
--- a/src/Network/Haskoin/Block.hs
+++ b/src/Network/Haskoin/Block.hs
@@ -1,3 +1,13 @@
+{-|
+Module      : Network.Haskoin.Block
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Most functions relating to blocks are exported by this module.
+-}
 module Network.Haskoin.Block
     ( module Network.Haskoin.Block.Common
       -- * Block Header Chain
diff --git a/src/Network/Haskoin/Block/Common.hs b/src/Network/Haskoin/Block/Common.hs
--- a/src/Network/Haskoin/Block/Common.hs
+++ b/src/Network/Haskoin/Block/Common.hs
@@ -1,4 +1,14 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-|
+Module      : Network.Haskoin.Block.Common
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Common data types and functions to handle blocks from the block chain.
+-}
 module Network.Haskoin.Block.Common
     ( Block(..)
     , BlockHeight
@@ -25,8 +35,7 @@
                                                      toJSON, withText)
 import           Data.Bits                          (shiftL, shiftR, (.&.),
                                                      (.|.))
-import           Data.ByteString                    (ByteString)
-import qualified Data.ByteString                    as BS
+import qualified Data.ByteString                    as B
 import           Data.Hashable                      (Hashable)
 import           Data.Maybe                         (fromMaybe)
 import           Data.Serialize                     (Serialize, decode, encode,
@@ -43,7 +52,7 @@
 import           Network.Haskoin.Util
 import qualified Text.Read                          as R
 
--- | Height of a block in the blockchain, starting at 0 for Genesis.
+-- | Height of a block in the block chain, starting at 0 for Genesis.
 type BlockHeight = Word32
 
 -- | Block timestamp as Unix time (seconds since 1970-01-01 00:00 UTC).
@@ -97,13 +106,13 @@
 -- | Block hashes are reversed with respect to the in-memory byte order in a
 -- block hash when displayed.
 blockHashToHex :: BlockHash -> Text
-blockHashToHex (BlockHash h) = encodeHex (BS.reverse (encode h))
+blockHashToHex (BlockHash h) = encodeHex (B.reverse (encode h))
 
 -- | Convert a human-readable hex block hash into a 'BlockHash'. Bytes are
 -- reversed as normal.
 hexToBlockHash :: Text -> Maybe BlockHash
 hexToBlockHash hex = do
-    bs <- BS.reverse <$> decodeHex hex
+    bs <- B.reverse <$> decodeHex hex
     h <- eitherToMaybe (decode bs)
     return $ BlockHash h
 
@@ -208,7 +217,7 @@
 -- only. The response to a 'GetHeaders' request is a 'Headers' message
 -- containing a list of block headers. A maximum of 2000 block headers can be
 -- returned. 'GetHeaders' is used by simplified payment verification (SPV)
--- clients to exclude block contents when synchronizing the blockchain.
+-- clients to exclude block contents when synchronizing the block chain.
 data GetHeaders =
     GetHeaders {
                  -- | protocol version
diff --git a/src/Network/Haskoin/Block/Headers.hs b/src/Network/Haskoin/Block/Headers.hs
--- a/src/Network/Haskoin/Block/Headers.hs
+++ b/src/Network/Haskoin/Block/Headers.hs
@@ -1,6 +1,16 @@
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE RecordWildCards   #-}
+{-|
+Module      : Network.Haskoin.Block.Headers
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Block chain header synchronization and proof-of-work consensus functions.
+-}
 module Network.Haskoin.Block.Headers
     ( BlockNode(..)
     , BlockHeaders(..)
@@ -86,11 +96,11 @@
 -- structure compact.
 type BlockMap = HashMap ShortBlockHash ShortByteString
 
--- | Represents accumulated work in the blockchain so far.
+-- | Represents accumulated work in the block chain so far.
 type BlockWork = Integer
 
 -- | Data structure representing a block header and its position in the
--- blockchain.
+-- block chain.
 data BlockNode
     -- | non-Genesis block header
     = BlockNode { nodeHeader :: !BlockHeader
@@ -251,7 +261,7 @@
         }
 
 -- | Validate a list of continuous block headers and import them to the
--- blockchain. Return 'Left' on failure with error information.
+-- block chain. Return 'Left' on failure with error information.
 connectBlocks :: BlockHeaders m
               => Network
               -> Timestamp       -- ^ current time
@@ -306,7 +316,7 @@
             -> m (Maybe BlockNode)
 parentBlock bh = getBlockHeader (prevBlock bh)
 
--- | Validate and connect single block header to the blockchain. Return 'Left' if fails
+-- | Validate and connect single block header to the block chain. Return 'Left' if fails
 -- to be validated.
 connectBlock ::
        BlockHeaders m
@@ -552,6 +562,7 @@
         blockTimestamp bh >
         blockTimestamp (nodeHeader par) + getTargetSpacing net * 2
 
+-- | Compute Bitcoin Cash DAA target for a new block.
 computeTarget :: Network -> BlockNode -> BlockNode -> Integer
 computeTarget net f l =
     let work = (nodeWork l - nodeWork f) * fromIntegral (getTargetSpacing net)
@@ -566,6 +577,7 @@
         work' = work `div` fromIntegral actualTimespan'
      in 2 ^ (256 :: Integer) `div` work'
 
+-- | Get suitable block for Bitcoin Cash DAA computation.
 getSuitableBlock :: BlockHeaders m => BlockNode -> m BlockNode
 getSuitableBlock par = do
     unless (nodeHeight par >= 3) $ error "Block height is less than three"
diff --git a/src/Network/Haskoin/Block/Merkle.hs b/src/Network/Haskoin/Block/Merkle.hs
--- a/src/Network/Haskoin/Block/Merkle.hs
+++ b/src/Network/Haskoin/Block/Merkle.hs
@@ -1,3 +1,13 @@
+{-|
+Module      : Network.Haskoin.Block.Merkle
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Function to deal with Merkle trees inside blocks.
+-}
 module Network.Haskoin.Block.Merkle
     ( MerkleBlock(..)
     , MerkleRoot
diff --git a/src/Network/Haskoin/Constants.hs b/src/Network/Haskoin/Constants.hs
--- a/src/Network/Haskoin/Constants.hs
+++ b/src/Network/Haskoin/Constants.hs
@@ -1,5 +1,16 @@
 {-# LANGUAGE DeriveGeneric     #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Constants
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Network constants for various networks, including Bitcoin SegWit (BTC), Bitcoin
+Cash (BCH), and corresponding public test and private regression test networks.
+-}
 module Network.Haskoin.Constants
     ( Network(..)
     , btc
@@ -14,7 +25,7 @@
     ) where
 
 import           Control.DeepSeq
-import           Data.ByteString             (ByteString)
+import           Data.ByteString              (ByteString)
 import           Data.List
 import           Data.Maybe
 import           Data.String
@@ -92,6 +103,8 @@
     , getCashAddrPrefix           :: !(Maybe Text)
       -- | 'Bech32' prefix (for SegWit network)
     , getBech32Prefix             :: !(Maybe Text)
+      -- | Replace-By-Fee (BIP-125)
+    , getReplaceByFee             :: !Bool
     } deriving (Eq, Generic)
 
 instance NFData Network
@@ -196,6 +209,7 @@
     , getSegWit = True
     , getCashAddrPrefix = Nothing
     , getBech32Prefix = Just "bc"
+    , getReplaceByFee = True
     }
 
 -- | Testnet for Bitcoin SegWit network.
@@ -251,6 +265,7 @@
     , getSegWit = True
     , getCashAddrPrefix = Nothing
     , getBech32Prefix = Just "tb"
+    , getReplaceByFee = True
     }
 
 -- | RegTest for Bitcoin SegWit network.
@@ -298,6 +313,7 @@
     , getSegWit = True
     , getCashAddrPrefix = Nothing
     , getBech32Prefix = Just "bcrt"
+    , getReplaceByFee = True
     }
 
 -- | Bitcoin Cash network. Symbol: BCH.
@@ -385,6 +401,7 @@
     , getSegWit = False
     , getCashAddrPrefix = Just "bitcoincash"
     , getBech32Prefix = Nothing
+    , getReplaceByFee = False
     }
 
 -- | Testnet for Bitcoin Cash network.
@@ -447,6 +464,7 @@
     , getSegWit = False
     , getCashAddrPrefix = Just "bchtest"
     , getBech32Prefix = Nothing
+    , getReplaceByFee = False
     }
 
 -- | RegTest for Bitcoin Cash network.
@@ -497,7 +515,9 @@
     , getSegWit = False
     , getCashAddrPrefix = Just "bchreg"
     , getBech32Prefix = Nothing
+    , getReplaceByFee = False
     }
 
+-- | List of all networks supported by this library.
 allNets :: [Network]
 allNets = [btc, bch, btcTest, bchTest, btcRegTest, bchRegTest]
diff --git a/src/Network/Haskoin/Crypto.hs b/src/Network/Haskoin/Crypto.hs
--- a/src/Network/Haskoin/Crypto.hs
+++ b/src/Network/Haskoin/Crypto.hs
@@ -1,6 +1,22 @@
+{-|
+Module      : Network.Haskoin.Crypto
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Hashing functions and ECDSA signatures.
+-}
 module Network.Haskoin.Crypto
-    ( module X
+    ( -- * Hashes
+      module Hash
+      -- * Signatures
+    , module Signature
+      -- * Secp256k1 (re-exported)
+    , module Secp256k1
     ) where
 
-import           Network.Haskoin.Crypto.Hash      as X
-import           Network.Haskoin.Crypto.Signature as X
+import           Crypto.Secp256k1                 as Secp256k1
+import           Network.Haskoin.Crypto.Hash      as Hash
+import           Network.Haskoin.Crypto.Signature as Signature
diff --git a/src/Network/Haskoin/Crypto/Hash.hs b/src/Network/Haskoin/Crypto/Hash.hs
--- a/src/Network/Haskoin/Crypto/Hash.hs
+++ b/src/Network/Haskoin/Crypto/Hash.hs
@@ -1,4 +1,15 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-|
+Module      : Network.Haskoin.Crypto.Hash
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Hashing functions and corresponding data types. Uses functions from the
+cryptonite library.
+-}
 module Network.Haskoin.Crypto.Hash
     ( -- * Hashes
       Hash512(getHash512)
diff --git a/src/Network/Haskoin/Crypto/Signature.hs b/src/Network/Haskoin/Crypto/Signature.hs
--- a/src/Network/Haskoin/Crypto/Signature.hs
+++ b/src/Network/Haskoin/Crypto/Signature.hs
@@ -1,15 +1,23 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Crypto.Signature
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+ECDSA signatures using secp256k1 curve. Uses functions from upstream secp256k1
+library.
+-}
 module Network.Haskoin.Crypto.Signature
-    ( -- * Signatures
-      Sig
-    , putSig
+    ( putSig
     , getSig
     , signHash
     , verifyHashSig
     , isCanonicalHalfOrder
     , decodeStrictSig
     , exportSig
-    , exportCompactSig
     ) where
 
 import           Control.Monad               (guard, unless, when)
diff --git a/src/Network/Haskoin/Keys.hs b/src/Network/Haskoin/Keys.hs
--- a/src/Network/Haskoin/Keys.hs
+++ b/src/Network/Haskoin/Keys.hs
@@ -1,3 +1,14 @@
+{-|
+Module      : Network.Haskoin.Keys
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+ECDSA private and public keys, extended keys (BIP-32) and mnemonic sentences
+(BIP-39).
+-}
 module Network.Haskoin.Keys
     ( module X
     ) where
diff --git a/src/Network/Haskoin/Keys/Common.hs b/src/Network/Haskoin/Keys/Common.hs
--- a/src/Network/Haskoin/Keys/Common.hs
+++ b/src/Network/Haskoin/Keys/Common.hs
@@ -1,16 +1,23 @@
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Keys.Common
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+ECDSA private and public key functions.
+-}
 module Network.Haskoin.Keys.Common
     ( -- * Public & Private Keys
       PubKeyI(..)
     , SecKeyI(..)
-    , PubKey
-    , SecKey
     , exportPubKey
     , importPubKey
     , wrapPubKey
-    , derivePubKey
     , derivePubKeyI
     , wrapSecKey
     , fromMiniKey
@@ -115,14 +122,15 @@
 wrapSecKey :: Bool -> SecKey -> SecKeyI
 wrapSecKey c d = SecKeyI d c
 
+-- | Deserialize 'SecKey'.
 secKeyGet :: Get SecKey
 secKeyGet = do
     bs <- getByteString 32
     maybe (fail "invalid private key") return (secKey bs)
 
+-- | Serialize 'SecKey'.
 secKeyPut :: Putter SecKey
 secKeyPut = putByteString . getSecKey
-
 
 -- | Decode Casascius mini private keys (22 or 30 characters).
 fromMiniKey :: ByteString -> Maybe SecKeyI
diff --git a/src/Network/Haskoin/Keys/Extended.hs b/src/Network/Haskoin/Keys/Extended.hs
--- a/src/Network/Haskoin/Keys/Extended.hs
+++ b/src/Network/Haskoin/Keys/Extended.hs
@@ -1,11 +1,18 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs             #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Keys.Extended
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+BIP-32 extended keys.
+-}
 module Network.Haskoin.Keys.Extended
     (
-      -- * Extended Keys
-      -- | See BIP32 for details:
-      -- <https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki>
       XPubKey(..)
     , XPrvKey(..)
     , ChainCode
@@ -84,13 +91,14 @@
 import           Control.DeepSeq                (NFData, rnf)
 import           Control.Exception              (Exception, throw)
 import           Control.Monad                  (guard, mzero, unless, (<=<))
+import           Crypto.Secp256k1
 import           Data.Aeson                     as A (FromJSON, ToJSON,
                                                       Value (String), parseJSON,
                                                       toJSON, withText)
 import           Data.Aeson.Types               (Parser)
 import           Data.Bits                      (clearBit, setBit, testBit)
 import           Data.ByteString                (ByteString)
-import qualified Data.ByteString                as BS
+import qualified Data.ByteString                as B
 import           Data.Either                    (fromRight)
 import           Data.List                      (foldl')
 import           Data.List.Split                (splitOn)
@@ -124,7 +132,10 @@
 
 instance Exception DerivationException
 
+-- | Chain code as specified in BIP-32.
 type ChainCode = Hash256
+
+-- | Index of key as specified in BIP-32.
 type KeyIndex = Word32
 
 -- | Data type representing an extended BIP32 private key. An extended key
@@ -241,8 +252,8 @@
     | otherwise = error "Invalid child derivation index"
   where
     pK = xPubKey $ deriveXPubKey xkey
-    msg = BS.append (exportPubKey True pK) (encode child)
-    (a, c) = split512 $ hmac512 (encode $ xPrvChain xkey) msg
+    m = B.append (exportPubKey True pK) (encode child)
+    (a, c) = split512 $ hmac512 (encode $ xPrvChain xkey) m
     k = fromMaybe err $ tweakSecKey (xPrvKey xkey) a
     err = throw $ DerivationException "Invalid prvSubKey derivation"
 
@@ -256,8 +267,8 @@
         XPubKey (xPubDepth xKey + 1) (xPubFP xKey) child c pK (xPubNet xKey)
     | otherwise = error "Invalid child derivation index"
   where
-    msg    = BS.append (exportPubKey True (xPubKey xKey)) (encode child)
-    (a, c) = split512 $ hmac512 (encode $ xPubChain xKey) msg
+    m      = B.append (exportPubKey True (xPubKey xKey)) (encode child)
+    (a, c) = split512 $ hmac512 (encode $ xPubChain xKey) m
     pK     = fromMaybe err $ tweakPubKey (xPubKey xKey) a
     err    = throw $ DerivationException "Invalid pubSubKey derivation"
 
@@ -276,8 +287,8 @@
     | otherwise = error "Invalid child derivation index"
   where
     i      = setBit child 31
-    msg    = BS.append (bsPadPrvKey $ xPrvKey xkey) (encode i)
-    (a, c) = split512 $ hmac512 (encode $ xPrvChain xkey) msg
+    m      = B.append (bsPadPrvKey $ xPrvKey xkey) (encode i)
+    (a, c) = split512 $ hmac512 (encode $ xPrvChain xkey) m
     k      = fromMaybe err $ tweakSecKey (xPrvKey xkey) a
     err    = throw $ DerivationException "Invalid hardSubKey derivation"
 
@@ -312,14 +323,14 @@
 -- | Computes the key fingerprint of an extended private key.
 xPrvFP :: XPrvKey -> Word32
 xPrvFP =
-    fromRight err . decode . BS.take 4 . encode . xPrvID
+    fromRight err . decode . B.take 4 . encode . xPrvID
   where
     err = error "Could not decode xPrvFP"
 
 -- | Computes the key fingerprint of an extended public key.
 xPubFP :: XPubKey -> Word32
 xPubFP =
-    fromRight err . decode . BS.take 4 . encode . xPubID
+    fromRight err . decode . B.take 4 . encode . xPubID
   where
     err = error "Could not decode xPubFP"
 
@@ -433,7 +444,7 @@
 -- public, soft derivation.
 deriveMSAddr :: Network -> [XPubKey] -> Int -> KeyIndex -> (Address, RedeemScript)
 deriveMSAddr net keys m i
-    | all ((== net) . xPubNet) keys = (p2shAddr net rdm, rdm)
+    | all ((== net) . xPubNet) keys = (payToScriptAddress net rdm, rdm)
     | otherwise = error "Some extended public keys on the wrong network"
   where
     rdm = sortMulSig $ PayMulSig k m
@@ -459,18 +470,32 @@
 
 {- Derivation Paths -}
 
+-- | Phantom type signaling a hardened derivation path that can only be computed
+-- from private extended key.
 data HardDeriv
+
+-- | Phantom type signaling no knowledge about derivation path: can be hardened or not.
 data AnyDeriv
+
+-- | Phantom type signaling derivation path including only non-hardened paths
+-- that can be computed from an extended public key.
 data SoftDeriv
 
+-- | Hardened derivation path. Can be computed from extended private key only.
 type HardPath = DerivPathI HardDeriv
+
+-- | Any derivation path.
 type DerivPath = DerivPathI AnyDeriv
+
+-- | Non-hardened derivation path can be computed from extended public key.
 type SoftPath = DerivPathI SoftDeriv
 
+-- | Helper class to perform validations on a hardened derivation path.
 class HardOrAny a
 instance HardOrAny HardDeriv
 instance HardOrAny AnyDeriv
 
+-- | Helper class to perform validations on a non-hardened derivation path.
 class AnyOrSoft a
 instance AnyOrSoft AnyDeriv
 instance AnyOrSoft SoftDeriv
diff --git a/src/Network/Haskoin/Keys/Mnemonic.hs b/src/Network/Haskoin/Keys/Mnemonic.hs
--- a/src/Network/Haskoin/Keys/Mnemonic.hs
+++ b/src/Network/Haskoin/Keys/Mnemonic.hs
@@ -1,5 +1,14 @@
 {-# LANGUAGE OverloadedStrings #-}
--- | Mnemonic keys (BIP-39). Only English dictionary.
+{-|
+Module      : Network.Haskoin.Keys.Mnemonic
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Mnemonic keys (BIP-39). Only English dictionary.
+-}
 module Network.Haskoin.Keys.Mnemonic
     ( -- * Mnemonic Sentences
       Entropy
@@ -18,7 +27,6 @@
 import qualified Data.ByteArray          as BA
 import           Data.ByteString         (ByteString)
 import qualified Data.ByteString         as BS
-import qualified Data.ByteString.Char8   as C (unwords, words)
 import           Data.List
 import qualified Data.Map.Strict         as M
 import           Data.Maybe
diff --git a/src/Network/Haskoin/Network.hs b/src/Network/Haskoin/Network.hs
--- a/src/Network/Haskoin/Network.hs
+++ b/src/Network/Haskoin/Network.hs
@@ -1,8 +1,14 @@
 {-|
-  This package provides basic types used for the Bitcoin networking protocol
-  together with Data.Serialize instances for efficiently serializing and
-  de-serializing them. More information on the bitcoin protocol is available
-  here: <http://en.bitcoin.it/wiki/Protocol_specification>
+Module      : Network.Haskoin.Network
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+This module provides basic types used for the Bitcoin networking protocol
+together with 'Data.Serialize' instances for efficiently serializing and
+de-serializing them.
 -}
 module Network.Haskoin.Network
     ( module Common
diff --git a/src/Network/Haskoin/Network/Bloom.hs b/src/Network/Haskoin/Network/Bloom.hs
--- a/src/Network/Haskoin/Network/Bloom.hs
+++ b/src/Network/Haskoin/Network/Bloom.hs
@@ -1,8 +1,15 @@
 {-|
-  Bloom filters are used to reduce data transfer when synchronizing thin cients.
-  When bloom filters are used a client will obtain filtered blocks that only
-  contain transactions that pass the bloom filter. Transactions announced via
-  inv messages also pass the filter.
+Module      : Network.Haskoin.Network.Bloom
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Bloom filters are used to reduce data transfer when synchronizing thin cients.
+When bloom filters are used a client will obtain filtered blocks that only
+contain transactions that pass the bloom filter. Transactions announced via inv
+messages also pass the filter.
 -}
 module Network.Haskoin.Network.Bloom
     ( -- * Bloom Filters
diff --git a/src/Network/Haskoin/Network/Common.hs b/src/Network/Haskoin/Network/Common.hs
--- a/src/Network/Haskoin/Network/Common.hs
+++ b/src/Network/Haskoin/Network/Common.hs
@@ -1,5 +1,15 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards   #-}
+{-|
+Module      : Network.Haskoin.Network.Common
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Common functions and data types related to peer-to-peer network.
+-}
 module Network.Haskoin.Network.Common
     ( -- * Network Data Types
       Addr(..)
@@ -305,7 +315,7 @@
            , rejectData    :: !ByteString
            } deriving (Eq, Show, Read)
 
-
+-- | Rejection code associated to the 'Reject' message.
 data RejectCode
     = RejectMalformed
     | RejectInvalid
diff --git a/src/Network/Haskoin/Network/Message.hs b/src/Network/Haskoin/Network/Message.hs
--- a/src/Network/Haskoin/Network/Message.hs
+++ b/src/Network/Haskoin/Network/Message.hs
@@ -1,3 +1,13 @@
+{-|
+Module      : Network.Haskoin.Network.Message
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Peer-to-peer network message serialization.
+-}
 module Network.Haskoin.Network.Message
     ( -- * Network Message
       Message(..)
diff --git a/src/Network/Haskoin/Script.hs b/src/Network/Haskoin/Script.hs
--- a/src/Network/Haskoin/Script.hs
+++ b/src/Network/Haskoin/Script.hs
@@ -1,7 +1,14 @@
 {-|
-  This package provides functions for parsing and evaluating bitcoin
-  transaction scripts. Data types are provided for building and
-  deconstructing all of the standard input and output script types.
+Module      : Network.Haskoin.Script
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+This module provides functions for parsing and evaluating bitcoin
+transaction scripts. Data types are provided for building and
+deconstructing all of the standard input and output script types.
 -}
 module Network.Haskoin.Script
     ( module X
diff --git a/src/Network/Haskoin/Script/Common.hs b/src/Network/Haskoin/Script/Common.hs
--- a/src/Network/Haskoin/Script/Common.hs
+++ b/src/Network/Haskoin/Script/Common.hs
@@ -1,4 +1,14 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Script.Common
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Common script-related functions and data types.
+-}
 module Network.Haskoin.Script.Common
 ( ScriptOp(..)
 , Script(..)
@@ -32,7 +42,6 @@
                                                      isEmpty)
 import           Data.Serialize.Put                 (putByteString, putWord16le,
                                                      putWord32le, putWord8)
-import           Data.String.Conversions
 import           Data.Word                          (Word8)
 import           Network.Haskoin.Crypto.Hash
 import           Network.Haskoin.Keys.Common
@@ -604,36 +613,37 @@
     rnf (PayWitnessScriptHash h) = rnf h
     rnf (DataCarrier a)          = rnf a
 
--- | Returns True if the script is a pay to public key output.
+-- | Is script a pay-to-public-key output?
 isPayPK :: ScriptOutput -> Bool
 isPayPK (PayPK _) = True
 isPayPK _         = False
 
--- | Returns True if the script is a pay to public key hash output.
+-- | Is script a pay-to-pub-key-hash output?
 isPayPKHash :: ScriptOutput -> Bool
 isPayPKHash (PayPKHash _) = True
 isPayPKHash _             = False
 
--- | Returns True if the script is a multisig output.
+-- | Is script a pay-to-multi-sig output?
 isPayMulSig :: ScriptOutput -> Bool
 isPayMulSig (PayMulSig _ _) = True
 isPayMulSig _               = False
 
--- | Returns true if the script is a pay to script hash output.
+-- | Is script a pay-to-script-hash output?
 isPayScriptHash :: ScriptOutput -> Bool
 isPayScriptHash (PayScriptHash _) = True
 isPayScriptHash _                 = False
 
--- | Returns true if the script is a pay to witness public key hash output.
+-- | Is script a pay-to-witness-pub-key-hash output?
 isPayWitnessPKHash :: ScriptOutput -> Bool
 isPayWitnessPKHash (PayWitnessPKHash _) = True
 isPayWitnessPKHash _                    = False
 
+-- | Is script a pay-to-witness-script-hash output?
 isPayWitnessScriptHash :: ScriptOutput -> Bool
 isPayWitnessScriptHash (PayWitnessScriptHash _) = True
 isPayWitnessScriptHash _                        = False
 
--- | Returns True if the script is an @OP_RETURN@ "datacarrier" output
+-- | Is script a data carrier output?
 isDataCarrier :: ScriptOutput -> Bool
 isDataCarrier (DataCarrier _) = True
 isDataCarrier _               = False
diff --git a/src/Network/Haskoin/Script/SigHash.hs b/src/Network/Haskoin/Script/SigHash.hs
--- a/src/Network/Haskoin/Script/SigHash.hs
+++ b/src/Network/Haskoin/Script/SigHash.hs
@@ -1,5 +1,15 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE OverloadedStrings          #-}
+{-|
+Module      : Network.Haskoin.Script.SigHash
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Transaction signatures and related functions.
+-}
 module Network.Haskoin.Script.SigHash
 ( SigHash
 , SigHashFlag(..)
@@ -26,6 +36,7 @@
 
 import           Control.DeepSeq                    (NFData, rnf)
 import           Control.Monad
+import           Crypto.Secp256k1
 import qualified Data.Aeson                         as J
 import           Data.Bits
 import           Data.ByteString                    (ByteString)
@@ -43,12 +54,18 @@
 import           Network.Haskoin.Transaction.Common
 import           Network.Haskoin.Util
 
+-- | Constant representing a SIGHASH flag that controls what is being signed.
 data SigHashFlag
     = SIGHASH_ALL
+      -- ^ sign all outputs
     | SIGHASH_NONE
+      -- ^ sign no outputs
     | SIGHASH_SINGLE
+      -- ^ sign the output index corresponding to the input
     | SIGHASH_FORKID
+      -- ^ replay protection for Bitcoin Cash transactions
     | SIGHASH_ANYONECANPAY
+      -- ^ new inputs can be added
     deriving (Eq, Ord, Show)
 
 instance Enum SigHashFlag where
@@ -86,57 +103,69 @@
 instance J.ToJSON SigHash where
     toJSON = J.Number . fromIntegral
 
+-- | SIGHASH_NONE as a byte.
 sigHashNone :: SigHash
 sigHashNone = fromIntegral $ fromEnum SIGHASH_NONE
 
+-- | SIGHASH_ALL as a byte.
 sigHashAll :: SigHash
 sigHashAll = fromIntegral $ fromEnum SIGHASH_ALL
 
+-- | SIGHASH_SINGLE as a byte.
 sigHashSingle :: SigHash
 sigHashSingle = fromIntegral $ fromEnum SIGHASH_SINGLE
 
+-- | SIGHASH_FORKID as a byte.
 sigHashForkId :: SigHash
 sigHashForkId = fromIntegral $ fromEnum SIGHASH_FORKID
 
+-- | SIGHASH_ANYONECANPAY as a byte.
 sigHashAnyoneCanPay :: SigHash
 sigHashAnyoneCanPay = fromIntegral $ fromEnum SIGHASH_ANYONECANPAY
 
+-- | Set SIGHASH_FORKID flag.
 setForkIdFlag :: SigHash -> SigHash
 setForkIdFlag = (.|. sigHashForkId)
 
+-- | Set SIGHASH_ANYONECANPAY flag.
 setAnyoneCanPayFlag :: SigHash -> SigHash
 setAnyoneCanPayFlag = (.|. sigHashAnyoneCanPay)
 
+-- | Is the SIGHASH_FORKID flag set?
 hasForkIdFlag :: SigHash -> Bool
 hasForkIdFlag = (/= 0) . (.&. sigHashForkId)
 
+-- | Is the SIGHASH_ANYONECANPAY flag set?
 hasAnyoneCanPayFlag :: SigHash -> Bool
 hasAnyoneCanPayFlag = (/= 0) . (.&. sigHashAnyoneCanPay)
 
--- | Returns True if the 'SigHash' has the value 'SIGHASH_ALL'.
+-- | Returns 'True' if the 'SigHash' has the value 'SIGHASH_ALL'.
 isSigHashAll :: SigHash -> Bool
 isSigHashAll = (== sigHashAll) . (.&. 0x1f)
 
--- | Returns True if the 'SigHash' has the value 'SIGHASH_NONE'.
+-- | Returns 'True' if the 'SigHash' has the value 'SIGHASH_NONE'.
 isSigHashNone :: SigHash -> Bool
 isSigHashNone = (== sigHashNone) . (.&. 0x1f)
 
--- | Returns True if the 'SigHash' has the value 'SIGHASH_SINGLE'.
+-- | Returns 'True' if the 'SigHash' has the value 'SIGHASH_SINGLE'.
 isSigHashSingle :: SigHash -> Bool
 isSigHashSingle = (== sigHashSingle) . (.&. 0x1f)
 
--- | Returns True if the 'SigHash' has the value 'SIGHASH_UNKNOWN'.
+-- | Returns 'True' if the 'SigHash' has the value 'SIGHASH_UNKNOWN'.
 isSigHashUnknown :: SigHash -> Bool
 isSigHashUnknown =
     (`notElem` [sigHashAll, sigHashNone, sigHashSingle]) . (.&. 0x1f)
 
+-- | Add a fork id to a 'SigHash'.
 sigHashAddForkId :: SigHash -> Word32 -> SigHash
 sigHashAddForkId sh w = (fromIntegral w `shiftL` 8) .|. (sh .&. 0x000000ff)
 
+-- | Add fork id of a particular network to a 'SigHash'.
 sigHashAddNetworkId :: Network -> SigHash -> SigHash
 sigHashAddNetworkId net =
     (`sigHashAddForkId` fromMaybe 0 (getSigHashForkId net))
 
+-- | Get fork id from 'SigHash'.
 sigHashGetForkId :: SigHash -> Word32
 sigHashGetForkId = fromIntegral . (`shiftR` 8)
 
diff --git a/src/Network/Haskoin/Script/Standard.hs b/src/Network/Haskoin/Script/Standard.hs
--- a/src/Network/Haskoin/Script/Standard.hs
+++ b/src/Network/Haskoin/Script/Standard.hs
@@ -1,19 +1,30 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Script.Standard
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Standard scripts like pay-to-public-key, pay-to-public-key-hash,
+pay-to-script-hash, pay-to-multisig and corresponding SegWit variants.
+-}
 module Network.Haskoin.Script.Standard
 ( ScriptInput(..)
 , SimpleInput(..)
 , RedeemScript
-, p2shAddr
-, p2wshAddr
-, outputAddress
 , inputAddress
+, outputAddress
 , encodeInput
 , encodeInputBS
 , decodeInput
 , decodeInputBS
-, addressToOutput
 , addressToScript
 , addressToScriptBS
+, addressToOutput
+, payToScriptAddress
+, payToWitnessScriptAddress
 , scriptToAddress
 , scriptToAddressBS
 , sortMulSig
@@ -46,13 +57,19 @@
 -- pay-to-script-hash transactions.
 data SimpleInput
       -- | spend pay-to-public-key output
-    = SpendPK     { getInputSig :: !TxSignature }
+    = SpendPK { getInputSig :: !TxSignature
+                  -- ^ transaction signature
+               }
       -- | spend pay-to-public-key-hash output
     | SpendPKHash { getInputSig :: !TxSignature
+                      -- ^ embedded signature
                   , getInputKey :: !PubKeyI
-                  }
+                      -- ^ public key
+                   }
       -- | spend multisig output
-    | SpendMulSig { getInputMulSigKeys :: ![TxSignature] }
+    | SpendMulSig { getInputMulSigKeys :: ![TxSignature]
+                      -- ^ list of signatures
+                   }
     deriving (Eq, Show)
 
 instance NFData SimpleInput where
@@ -86,48 +103,50 @@
 -- script. It must be included in inputs that spend pay-to-script-hash outputs.
 type RedeemScript = ScriptOutput
 
+-- | Standard input script high-level representation.
 data ScriptInput
-    = RegularInput    { getRegularInput     :: SimpleInput }
-    | ScriptHashInput { getScriptHashInput  :: SimpleInput
-                      , getScriptHashRedeem :: RedeemScript
-                      }
+    = RegularInput    {
+        getRegularInput     :: SimpleInput
+            -- ^ get wrapped simple input
+        }
+    | ScriptHashInput {
+            getScriptHashInput  :: SimpleInput
+                -- ^ get simple input associated with redeem script
+            , getScriptHashRedeem :: RedeemScript
+                -- ^ redeem script
+            }
     deriving (Eq, Show)
 
 instance NFData ScriptInput where
     rnf (RegularInput i)      = rnf i
     rnf (ScriptHashInput i o) = rnf i `seq` rnf o
 
-
 -- | Compute a pay-to-script-hash address for an output script.
-p2shAddr :: Network -> ScriptOutput -> Address
-p2shAddr net out = ScriptAddress (addressHash (encodeOutputBS out)) net
+payToScriptAddress :: Network -> ScriptOutput -> Address
+payToScriptAddress net out = p2shAddr net (addressHash (encodeOutputBS out))
 
 -- | Compute a pay-to-witness-script-hash address for an output script. Only on
 -- SegWit networks.
-p2wshAddr :: Network -> ScriptOutput -> Maybe Address
-p2wshAddr net out = do
-    guard (getSegWit net)
-    return $ WitnessScriptAddress (sha256 (encodeOutputBS out)) net
+payToWitnessScriptAddress :: Network -> ScriptOutput -> Maybe Address
+payToWitnessScriptAddress net out = p2wshAddr net (sha256 (encodeOutputBS out))
 
 -- | Encode an output script from an address. Will fail if using a
 -- pay-to-witness address on a non-SegWit network.
-addressToOutput :: Address -> Maybe ScriptOutput
-addressToOutput (PubKeyAddress h _)        = Just (PayPKHash h)
-addressToOutput (ScriptAddress h _)        = Just (PayScriptHash h)
-addressToOutput (WitnessPubKeyAddress h n)
-    | getSegWit n = Just (PayWitnessPKHash h)
-    | otherwise = Nothing
-addressToOutput (WitnessScriptAddress h n)
-    | getSegWit n = Just (PayWitnessScriptHash h)
-    | otherwise = Nothing
+addressToOutput :: Address -> ScriptOutput
+addressToOutput a
+    | isPubKeyAddress a = PayPKHash (getAddrHash160 a)
+    | isScriptAddress a = PayScriptHash (getAddrHash160 a)
+    | isWitnessPubKeyAddress a = PayWitnessPKHash (getAddrHash160 a)
+    | isWitnessScriptAddress a = PayWitnessScriptHash (getAddrHash256 a)
+    | otherwise = undefined
 
 -- | Get output script AST for an 'Address'.
-addressToScript :: Address -> Maybe Script
-addressToScript a = encodeOutput <$> addressToOutput a
+addressToScript :: Address -> Script
+addressToScript = encodeOutput . addressToOutput
 
 -- | Encode address as output script in 'ByteString' form.
-addressToScriptBS :: Address -> Maybe ByteString
-addressToScriptBS a = encode <$> addressToScript a
+addressToScriptBS :: Address -> ByteString
+addressToScriptBS = encode . addressToScript
 
 -- | Decode an output script into an 'Address' if it has such representation.
 scriptToAddress :: Network -> Script -> Maybe Address
@@ -141,20 +160,22 @@
 outputAddress :: Network -> ScriptOutput -> Either String Address
 outputAddress net s =
     case s of
-        PayPKHash h -> return $ PubKeyAddress h net
-        PayScriptHash h -> return $ ScriptAddress h net
-        PayPK k -> return $ pubKeyAddr net k
-        PayWitnessPKHash h
-            | getSegWit net -> return $ WitnessPubKeyAddress h net
-        PayWitnessScriptHash h
-            | getSegWit net -> return $ WitnessScriptAddress h net
+        PayPKHash h -> Right $ p2pkhAddr net h
+        PayScriptHash h -> Right $ p2shAddr net h
+        PayPK k -> Right $ pubKeyAddr net k
+        PayWitnessPKHash h ->
+            maybeToEither "outputAddress: segwit not supported in this network" $
+            p2wpkhAddr net h
+        PayWitnessScriptHash h ->
+            maybeToEither "outputAddress: segwit not supported in this network" $
+            p2wshAddr net h
         _ -> Left "outputAddress: bad output script type"
 
 -- | Infer the address of a 'ScriptInput'
 inputAddress :: Network -> ScriptInput -> Either String Address
 inputAddress net s = case s of
     RegularInput (SpendPKHash _ key) -> return $ pubKeyAddr net key
-    ScriptHashInput _ rdm -> return $ p2shAddr net rdm
+    ScriptHashInput _ rdm -> return $ payToScriptAddress net rdm
     _ -> Left "inputAddress: bad input script type"
 
 -- | Heuristic to decode an input script into one of the standard types.
diff --git a/src/Network/Haskoin/Test.hs b/src/Network/Haskoin/Test.hs
--- a/src/Network/Haskoin/Test.hs
+++ b/src/Network/Haskoin/Test.hs
@@ -1,5 +1,12 @@
 {-|
-  This package provides test types for Network.Haskoin
+Module      : Network.Haskoin.Test
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Arbitrary instances for testing.
 -}
 module Network.Haskoin.Test
     ( module X
diff --git a/src/Network/Haskoin/Test/Address.hs b/src/Network/Haskoin/Test/Address.hs
--- a/src/Network/Haskoin/Test/Address.hs
+++ b/src/Network/Haskoin/Test/Address.hs
@@ -1,5 +1,10 @@
 {-|
-  Arbitrary types for Network.Haskoin.Crypto
+Module      : Network.Haskoin.Test.Address
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 -}
 module Network.Haskoin.Test.Address where
 
@@ -15,8 +20,8 @@
 
 -- | Arbitrary pay-to-public-key-hash address.
 arbitraryPubKeyAddress :: Network -> Gen Address
-arbitraryPubKeyAddress net = PubKeyAddress <$> arbitraryHash160 <*> pure net
+arbitraryPubKeyAddress net = p2pkhAddr net <$> arbitraryHash160
 
 -- | Arbitrary pay-to-script-hash address.
 arbitraryScriptAddress :: Network -> Gen Address
-arbitraryScriptAddress net = ScriptAddress <$> arbitraryHash160 <*> pure net
+arbitraryScriptAddress net = p2shAddr net <$> arbitraryHash160
diff --git a/src/Network/Haskoin/Test/Block.hs b/src/Network/Haskoin/Test/Block.hs
--- a/src/Network/Haskoin/Test/Block.hs
+++ b/src/Network/Haskoin/Test/Block.hs
@@ -1,5 +1,10 @@
 {-|
-  Arbitrary types for Network.Haskoin.Block
+Module      : Network.Haskoin.Test.Block
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 -}
 module Network.Haskoin.Test.Block where
 
diff --git a/src/Network/Haskoin/Test/Crypto.hs b/src/Network/Haskoin/Test/Crypto.hs
--- a/src/Network/Haskoin/Test/Crypto.hs
+++ b/src/Network/Haskoin/Test/Crypto.hs
@@ -1,5 +1,10 @@
 {-|
-  Arbitrary types for Network.Haskoin.Crypto
+Module      : Network.Haskoin.Test.Crypto
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 -}
 module Network.Haskoin.Test.Crypto where
 
diff --git a/src/Network/Haskoin/Test/Keys.hs b/src/Network/Haskoin/Test/Keys.hs
--- a/src/Network/Haskoin/Test/Keys.hs
+++ b/src/Network/Haskoin/Test/Keys.hs
@@ -1,14 +1,18 @@
 {-|
-  Arbitrary types for Network.Haskoin.Crypto
+Module      : Network.Haskoin.Test.Keys
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 -}
 module Network.Haskoin.Test.Keys where
 
-import           Data.Bits                        (clearBit)
-import           Data.List                        (foldl')
-import           Data.Word                        (Word32)
+import           Data.Bits                     (clearBit)
+import           Data.List                     (foldl')
+import           Data.Word                     (Word32)
 import           Network.Haskoin.Constants
-import           Network.Haskoin.Crypto.Hash
-import           Network.Haskoin.Crypto.Signature
+import           Network.Haskoin.Crypto
 import           Network.Haskoin.Keys.Common
 import           Network.Haskoin.Keys.Extended
 import           Network.Haskoin.Test.Crypto
@@ -77,7 +81,7 @@
 -- nonce.
 arbitrarySignature :: Gen (Hash256, SecKey, Sig)
 arbitrarySignature = do
-    msg <- arbitraryHash256
+    m <- arbitraryHash256
     key <- arbitrary
-    let sig = signHash key msg
-    return (msg, key, sig)
+    let sig = signHash key m
+    return (m, key, sig)
diff --git a/src/Network/Haskoin/Test/Message.hs b/src/Network/Haskoin/Test/Message.hs
--- a/src/Network/Haskoin/Test/Message.hs
+++ b/src/Network/Haskoin/Test/Message.hs
@@ -1,5 +1,10 @@
 {-|
-  Arbitrary types for Network.Haskoin.Node.Message
+Module      : Network.Haskoin.Test.Message
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 -}
 module Network.Haskoin.Test.Message where
 
diff --git a/src/Network/Haskoin/Test/Network.hs b/src/Network/Haskoin/Test/Network.hs
--- a/src/Network/Haskoin/Test/Network.hs
+++ b/src/Network/Haskoin/Test/Network.hs
@@ -1,5 +1,10 @@
 {-|
-  Arbitrary types for Network.Haskoin.Network
+Module      : Network.Haskoin.Test.Network
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 -}
 module Network.Haskoin.Test.Network where
 
diff --git a/src/Network/Haskoin/Test/Script.hs b/src/Network/Haskoin/Test/Script.hs
--- a/src/Network/Haskoin/Test/Script.hs
+++ b/src/Network/Haskoin/Test/Script.hs
@@ -1,8 +1,14 @@
 {-|
-  Arbitrary types for Network.Haskoin.Script
+Module      : Network.Haskoin.Test.Script
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 -}
 module Network.Haskoin.Test.Script where
 
+import           Crypto.Secp256k1
 import           Data.Maybe
 import           Data.Word
 import           Network.Haskoin.Address
diff --git a/src/Network/Haskoin/Test/Transaction.hs b/src/Network/Haskoin/Test/Transaction.hs
--- a/src/Network/Haskoin/Test/Transaction.hs
+++ b/src/Network/Haskoin/Test/Transaction.hs
@@ -1,5 +1,10 @@
 {-|
-  Arbitrary types for Network.Haskoin.Transaction.
+Module      : Network.Haskoin.Test.Transaction
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
 -}
 module Network.Haskoin.Test.Transaction where
 import           Control.Monad
@@ -18,6 +23,7 @@
 import           Network.Haskoin.Transaction
 import           Test.QuickCheck
 
+-- | Wrapped coin value for testing.
 newtype TestCoin = TestCoin { getTestCoin :: Word64 }
     deriving (Eq, Show)
 
@@ -61,6 +67,7 @@
 arbitraryWitnessTx :: Network -> Gen Tx
 arbitraryWitnessTx net = arbitraryWLTx net True
 
+-- | Arbitrary witness or legacy transaction.
 arbitraryWLTx :: Network -> Bool -> Gen Tx
 arbitraryWLTx net wit = do
     ni <- choose (0, 5)
@@ -139,6 +146,7 @@
 arbitraryPKHashSigInput :: Network -> Gen (SigInput, SecKeyI)
 arbitraryPKHashSigInput net = arbitraryAnyInput net True
 
+-- | Arbitrary 'SigInput'.
 arbitraryAnyInput :: Network -> Bool -> Gen (SigInput, SecKeyI)
 arbitraryAnyInput net pkh = do
     (k, p) <- arbitraryKeyPair
@@ -147,6 +155,7 @@
     (val, op, sh) <- arbitraryInputStuff net
     return (SigInput out val op sh Nothing, k)
 
+-- | Arbitrary value, out point and sighash for an input.
 arbitraryInputStuff :: Network -> Gen (Word64, OutPoint, SigHash)
 arbitraryInputStuff net = do
     val <- getTestCoin <$> arbitrarySatoshi net
@@ -174,7 +183,7 @@
         , f <$> arbitraryPKHashSigInput net
         , arbitraryMSSigInput net
         ]
-    let out = PayScriptHash $ getAddrHash160 $ p2shAddr net rdm
+    let out = PayScriptHash $ getAddrHash160 $ payToScriptAddress net rdm
     return (SigInput out val op sh $ Just rdm, ks)
   where
     f (si, k) = (si, [k])
@@ -216,7 +225,7 @@
     res <-
         forM (map prevOutput $ txIn tx) $ \op -> do
             (so, val, rdmM, prvs, m, n) <- arbitraryData
-            txs <- mapM (singleSig so val rdmM tx op) prvs
+            txs <- mapM (singleSig so val rdmM tx op . secKeyData) prvs
             return (txs, (so, val, op, m, n))
     return (concatMap fst res, map snd res)
   where
@@ -236,7 +245,7 @@
         let so = PayMulSig pubKeys m
         elements
             [ (so, val, Nothing, prvKeys, m, n)
-            , ( PayScriptHash $ getAddrHash160 $ p2shAddr net so
+            , ( PayScriptHash $ getAddrHash160 $ payToScriptAddress net so
               , val
               , Just so
               , prvKeys
diff --git a/src/Network/Haskoin/Test/Util.hs b/src/Network/Haskoin/Test/Util.hs
--- a/src/Network/Haskoin/Test/Util.hs
+++ b/src/Network/Haskoin/Test/Util.hs
@@ -1,3 +1,11 @@
+{-|
+Module      : Network.Haskoin.Test.Util
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+-}
 module Network.Haskoin.Test.Util where
 
 import           Data.ByteString       (ByteString, pack)
diff --git a/src/Network/Haskoin/Transaction.hs b/src/Network/Haskoin/Transaction.hs
--- a/src/Network/Haskoin/Transaction.hs
+++ b/src/Network/Haskoin/Transaction.hs
@@ -1,6 +1,12 @@
 {-|
-  This package provides functions for building and signing both simple
-  transactions and multisignature transactions.
+Module      : Network.Haskoin.Transaction
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Transactions and related code.
 -}
 module Network.Haskoin.Transaction
     ( module Common
diff --git a/src/Network/Haskoin/Transaction/Builder.hs b/src/Network/Haskoin/Transaction/Builder.hs
--- a/src/Network/Haskoin/Transaction/Builder.hs
+++ b/src/Network/Haskoin/Transaction/Builder.hs
@@ -1,5 +1,16 @@
 {-# LANGUAGE LambdaCase        #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : Network.Haskoin.Transaction.Builder
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Code to simplify transaction creation, signing, fee calculation and coin
+selection.
+-}
 module Network.Haskoin.Transaction.Builder
     ( -- * Transaction Creation & Signing
       buildAddrTx
@@ -32,12 +43,12 @@
 import           Control.DeepSeq                    (NFData, rnf)
 import           Control.Monad                      (foldM, mzero, unless, when)
 import           Control.Monad.Identity             (runIdentity)
+import           Crypto.Secp256k1
 import           Data.Aeson                         (FromJSON, ToJSON,
                                                      Value (Object), object,
                                                      parseJSON, toJSON, (.:),
                                                      (.:?), (.=))
-import           Data.ByteString                    (ByteString)
-import qualified Data.ByteString                    as BS
+import qualified Data.ByteString                    as B
 import           Data.Conduit                       (ConduitT, Void, await,
                                                      runConduit, (.|))
 import           Data.Conduit.List                  (sourceList)
@@ -203,8 +214,8 @@
 guessTxSize pki msi pkout msout =
     8 + inpLen + inp + outLen + out
   where
-    inpLen = BS.length $ encode $ VarInt $ fromIntegral $ length msi + pki
-    outLen = BS.length $ encode $ VarInt $ fromIntegral $ pkout + msout
+    inpLen = B.length $ encode $ VarInt $ fromIntegral $ length msi + pki
+    outLen = B.length $ encode $ VarInt $ fromIntegral $ pkout + msout
     inp = pki * 148 + sum (map guessMSSize msi)
              -- (20: hash160) + (5: opcodes) +
              -- (1: script len) + (8: Word64)
@@ -218,12 +229,12 @@
 guessMSSize :: (Int,Int) -> Int
 guessMSSize (m, n)
     -- OutPoint (36) + Sequence (4) + Script
- = 40 + fromIntegral (BS.length $ encode $ VarInt $ fromIntegral scp) + scp
+ = 40 + fromIntegral (B.length $ encode $ VarInt $ fromIntegral scp) + scp
     -- OP_M + n*PubKey + OP_N + OP_CHECKMULTISIG
   where
     rdm =
         fromIntegral $
-        BS.length $ encode $ opPushData $ BS.replicate (n * 34 + 3) 0
+        B.length $ encode $ opPushData $ B.replicate (n * 34 + 3) 0
     -- Redeem + m*sig + OP_0
     scp = rdm + m * 73 + 1
 
@@ -237,7 +248,7 @@
     f (s, v) =
         maybe (Left ("buildAddrTx: Invalid address " ++ cs s)) Right $ do
             a <- stringToAddr net s
-            o <- addressToOutput a
+            let o = addressToOutput a
             return (o, v)
 
 -- | Build a transaction by providing a list of outpoints as inputs
@@ -246,7 +257,7 @@
 buildTx xs ys =
     mapM fo ys >>= \os -> return $ Tx 1 (map fi xs) os [] 0
   where
-    fi outPoint = TxIn outPoint BS.empty maxBound
+    fi outPoint = TxIn outPoint B.empty maxBound
     fo (o, v)
         | v <= 2100000000000000 = return $ TxOut v $ encodeOutputBS o
         | otherwise =
@@ -292,7 +303,7 @@
 signTx :: Network
        -> Tx               -- ^ transaction to sign
        -> [SigInput]       -- ^ signing parameters
-       -> [SecKeyI]        -- ^ wrapped private keys to sign with
+       -> [SecKey]        -- ^ private keys to sign with
        -> Either String Tx -- ^ signed transaction
 signTx net otx sigis allKeys
     | null ti   = Left "signTx: Transaction has no inputs"
@@ -306,13 +317,13 @@
 -- | Sign a single input in a transaction deterministically (RFC-6979).
 signInput :: Network -> Tx -> Int -> SigInput -> SecKeyI -> Either String Tx
 signInput net tx i (SigInput so val _ sh rdmM) key = do
-    let sig = TxSignature (signHash (secKeyData key) msg) sh
+    let sig = TxSignature (signHash (secKeyData key) m) sh
     si <- buildInput net tx i so val rdmM sig $ derivePubKeyI key
     let ins = updateIndex i (txIn tx) (f si)
     return $ Tx (txVersion tx) ins (txOut tx) [] (txLockTime tx)
   where
     f si x = x {scriptInput = encodeInputBS si}
-    msg = txSigHash net tx (encodeOutput $ fromMaybe so rdmM) val i sh
+    m = txSigHash net tx (encodeOutput $ fromMaybe so rdmM) val i sh
 
 -- | Order the 'SigInput' with respect to the transaction inputs. This allows
 -- the user to provide the 'SigInput' in any order. Users can also provide only
@@ -331,7 +342,7 @@
        Network
     -> ScriptOutput
     -> Maybe RedeemScript
-    -> [SecKeyI]
+    -> [SecKey]
     -> Either String [SecKeyI]
 sigKeys net so rdmM keys =
     case (so, rdmM) of
@@ -345,7 +356,13 @@
         (PayScriptHash _, Just rdm) -> sigKeys net rdm Nothing keys
         _ -> Left "sigKeys: Could not decode output script"
   where
-    zipKeys = map (\k -> (k, derivePubKeyI k)) keys
+    zipKeys =
+        [ (prv, pub)
+        | k <- keys
+        , t <- [True, False]
+        , let prv = wrapSecKey t k
+        , let pub = derivePubKeyI prv
+        ]
 
 -- | Construct an input for a transaction given a signature, public key and data
 -- about the previous output.
@@ -399,7 +416,7 @@
     outs = map (first $ (\(o,v,_) -> (o,v)) . fromJust) $ filter (isJust . fst) zipOp
     f (_, _, o) txin = o == prevOutput txin
     emptyTxs = map (\tx -> foldl clearInput tx outs) txs
-    ins is i = updateIndex i is (\ti -> ti{ scriptInput = BS.empty })
+    ins is i = updateIndex i is (\ti -> ti{ scriptInput = B.empty })
     clearInput tx (_, i) =
         Tx (txVersion tx) (ins (txIn tx) i) (txOut tx) [] (txLockTime tx)
 
@@ -414,7 +431,7 @@
     -- Ignore transactions with empty inputs
  = do
     let ins = map (scriptInput . (!! i) . txIn) txs
-    sigRes <- mapM extractSigs $ filter (not . BS.null) ins
+    sigRes <- mapM extractSigs $ filter (not . B.null) ins
     let rdm = snd $ head sigRes
     unless (all (== rdm) $ map snd sigRes) $ Left "Redeem scripts do not match"
     si <- encodeInputBS <$> go (nub $ concatMap fst sigRes) so rdm
@@ -477,7 +494,7 @@
             Right (RegularInput (SpendPKHash (TxSignature sig sh) pub)) ->
                 case so of
                     PayPKHash h ->
-                        pubKeyAddr net pub == PubKeyAddress h net &&
+                        pubKeyAddr net pub == p2pkhAddr net h &&
                         verifyHashSig
                             (txSigHash net tx out val i sh)
                             sig
@@ -492,7 +509,7 @@
             Right (ScriptHashInput si rdm) ->
                 case so of
                     PayScriptHash h ->
-                        p2shAddr net rdm == ScriptAddress h net &&
+                        payToScriptAddress net rdm == p2shAddr net h &&
                         go (encodeInputBS $ RegularInput si) rdm val
                     _ -> False
             _ -> False
diff --git a/src/Network/Haskoin/Transaction/Common.hs b/src/Network/Haskoin/Transaction/Common.hs
--- a/src/Network/Haskoin/Transaction/Common.hs
+++ b/src/Network/Haskoin/Transaction/Common.hs
@@ -1,5 +1,15 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE OverloadedStrings          #-}
+{-|
+Module      : Network.Haskoin.Transaction.Common
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+Code related to transactions parsing and serialization.
+-}
 module Network.Haskoin.Transaction.Common
     ( Tx(..)
     , TxIn(..)
diff --git a/src/Network/Haskoin/Util.hs b/src/Network/Haskoin/Util.hs
--- a/src/Network/Haskoin/Util.hs
+++ b/src/Network/Haskoin/Util.hs
@@ -1,7 +1,13 @@
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-|
-  This module defines various utility functions used across the
-  Network.Haskoin modules.
+Module      : Network.Haskoin.Util
+Copyright   : No rights reserved
+License     : UNLICENSE
+Maintainer  : xenog@protonmail.com
+Stability   : experimental
+Portability : POSIX
+
+This module defines various utility functions used across the library.
 -}
 module Network.Haskoin.Util
     (
diff --git a/test/Network/Haskoin/Address/CashAddrSpec.hs b/test/Network/Haskoin/Address/CashAddrSpec.hs
--- a/test/Network/Haskoin/Address/CashAddrSpec.hs
+++ b/test/Network/Haskoin/Address/CashAddrSpec.hs
@@ -2,7 +2,6 @@
 module Network.Haskoin.Address.CashAddrSpec (spec) where
 
 import           Control.Monad
-import           Data.ByteString                  (ByteString)
 import qualified Data.ByteString.Char8            as C
 import           Data.Maybe
 import           Data.String.Conversions
@@ -10,7 +9,6 @@
 import           Network.Haskoin.Address
 import           Network.Haskoin.Address.CashAddr
 import           Network.Haskoin.Constants
-import           Network.Haskoin.Crypto
 import           Network.Haskoin.Util
 import           Test.Hspec
 import           Test.HUnit
@@ -76,18 +74,18 @@
 
   describe "cashaddr larger test vectors" $
       forM_ (zip [0..] vectors) $ \(i, vec) ->
-          it ("cashaddr test vector " <> show i) $ testCashAddr vec
+          it ("cashaddr test vector " <> show (i :: Int)) $ testCashAddr vec
 
 {- Various utilities -}
 
 base58ToCashAddr :: Text -> Maybe Text
-base58ToCashAddr b58 = fromBase58 b58 >>= toCashAddr
+base58ToCashAddr b58 = toCashAddr <$> fromBase58 b58
   where
     fromBase58 = stringToAddr btc
     toCashAddr a = addrToString a { getAddrNet = bch }
 
 cashAddrtoBase58 :: Text -> Maybe Text
-cashAddrtoBase58 c32 = fromCashAddr c32 >>= toBase58
+cashAddrtoBase58 c32 = toBase58 <$> fromCashAddr c32
   where
     fromCashAddr = stringToAddr bch
     toBase58 a = addrToString a { getAddrNet = btc }
@@ -96,21 +94,19 @@
 testCashAddr (len, typ, addr, hex) = do
     let mbs = decodeHex hex
     assertBool "Could not decode hex payload from test vector" (isJust mbs)
-    let Just bs = mbs
     let mlow = cash32decode addr
     assertBool "Could not decode low level address" (isJust mlow)
-    let Just (lpfx, lbs) = mlow
+    let Just (_, lbs) = mlow
     assertEqual "Low-level payload size incorrect" len (C.length lbs - 1)
     assertEqual "Low-level payload doesn't match" bs (C.tail lbs)
     let mdec = cash32decodeType addr
     assertBool ("Could not decode test address: " <> cs addr) (isJust mdec)
-    let Just (pfx, ver, pay) = mdec
     assertEqual "Length doesn't match" len (C.length pay)
     assertEqual "Version doesn't match" typ ver
     assertEqual "Payload doesn't match" bs pay
   where
     Just bs = decodeHex hex
-    Just (pfx, ver, pay) = cash32decodeType addr
+    Just (_, ver, pay) = cash32decodeType addr
 
 -- | All vectors starting with @pref@ had the wrong version in the spec
 -- document.
diff --git a/test/Network/Haskoin/AddressSpec.hs b/test/Network/Haskoin/AddressSpec.hs
--- a/test/Network/Haskoin/AddressSpec.hs
+++ b/test/Network/Haskoin/AddressSpec.hs
@@ -9,7 +9,6 @@
 import           Network.Haskoin.Address
 import           Network.Haskoin.Address.Base58
 import           Network.Haskoin.Constants
-import           Network.Haskoin.Crypto
 import           Network.Haskoin.Test
 import           Test.Hspec
 import           Test.HUnit                     (Assertion, assertBool)
@@ -40,7 +39,7 @@
     it "encodes and decodes address" $
         property $
         forAll (arbitraryAddress net) $ \a ->
-            (stringToAddr net =<< addrToString a) == Just a
+            stringToAddr net (addrToString a) == Just a
     it "shows and reads address" $
         property $ forAll (arbitraryAddress net) $ \a -> read (show a) == a
 
diff --git a/test/Network/Haskoin/CryptoSpec.hs b/test/Network/Haskoin/CryptoSpec.hs
--- a/test/Network/Haskoin/CryptoSpec.hs
+++ b/test/Network/Haskoin/CryptoSpec.hs
@@ -1,12 +1,10 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Network.Haskoin.CryptoSpec (spec) where
 
-import           Control.Monad             (forM_, replicateM_)
-import           Control.Monad.Trans       (liftIO)
+import           Control.Monad
 import           Data.ByteString           (ByteString)
 import qualified Data.ByteString.Char8     as C (pack)
 import           Data.Maybe                (fromMaybe, isJust, isNothing)
-import           Data.Serialize            (encode)
 import           Data.Text                 (Text)
 import           Network.Haskoin.Address
 import           Network.Haskoin.Constants
@@ -138,10 +136,10 @@
 
 checkMatchingAddress :: Assertion
 checkMatchingAddress = do
-    assertBool "Key 1"  $ Just addr1  == addrToString (pubKeyAddr btc pub1)
-    assertBool "Key 2"  $ Just addr2  == addrToString (pubKeyAddr btc pub2)
-    assertBool "Key 1C" $ Just addr1C == addrToString (pubKeyAddr btc pub1C)
-    assertBool "Key 2C" $ Just addr2C == addrToString (pubKeyAddr btc pub2C)
+    assertBool "Key 1"  $ addr1  == addrToString (pubKeyAddr btc pub1)
+    assertBool "Key 2"  $ addr2  == addrToString (pubKeyAddr btc pub2)
+    assertBool "Key 1C" $ addr1C == addrToString (pubKeyAddr btc pub1C)
+    assertBool "Key 2C" $ addr2C == addrToString (pubKeyAddr btc pub2C)
 
 checkSignatures :: Hash256 -> Assertion
 checkSignatures h = do
diff --git a/test/Network/Haskoin/Keys/ExtendedSpec.hs b/test/Network/Haskoin/Keys/ExtendedSpec.hs
--- a/test/Network/Haskoin/Keys/ExtendedSpec.hs
+++ b/test/Network/Haskoin/Keys/ExtendedSpec.hs
@@ -4,7 +4,6 @@
 import           Data.Aeson                 as A
 import           Data.Aeson.Types           as A
 import           Data.Bits                  ((.&.))
-import           Data.ByteString            (ByteString)
 import qualified Data.ByteString.Lazy.Char8 as B8
 import           Data.Either                (isLeft)
 import           Data.Map.Strict            (singleton)
@@ -16,7 +15,6 @@
 import           Data.Word                  (Word32)
 import           Network.Haskoin.Address
 import           Network.Haskoin.Constants
-import           Network.Haskoin.Crypto
 import           Network.Haskoin.Keys
 import           Network.Haskoin.Test
 import           Network.Haskoin.Util
@@ -295,7 +293,7 @@
     assertBool "xPrvID" $ encodeHex (S.encode $ xPrvID m) == head v
     assertBool "xPrvFP" $ encodeHex (S.encode $ xPrvFP m) == v !! 1
     assertBool "xPrvAddr" $
-        addrToString (xPubAddr $ deriveXPubKey m) == Just (v !! 2)
+        addrToString (xPubAddr $ deriveXPubKey m) == v !! 2
     assertBool "prvKey" $ encodeHex (getSecKey $ xPrvKey m) == v !! 3
     assertBool "xPrvWIF" $ xPrvWif m == v !! 4
     assertBool "pubKey" $
diff --git a/test/Network/Haskoin/ScriptSpec.hs b/test/Network/Haskoin/ScriptSpec.hs
--- a/test/Network/Haskoin/ScriptSpec.hs
+++ b/test/Network/Haskoin/ScriptSpec.hs
@@ -2,18 +2,12 @@
 module Network.Haskoin.ScriptSpec (spec) where
 
 import           Control.Monad
-import           Control.Monad.IO.Class
 import           Data.Aeson                  as A
 import           Data.ByteString             (ByteString)
-import qualified Data.ByteString             as BS
-import qualified Data.ByteString.Char8       as C
-import qualified Data.ByteString.Lazy        as BL
-import qualified Data.ByteString.Lazy.Char8  as CL
-import           Data.Char                   (ord)
+import qualified Data.ByteString             as B
+import qualified Data.ByteString.Lazy        as L
 import           Data.Either
-import           Data.Int                    (Int64)
 import           Data.List
-import           Data.List.Split             (splitOn)
 import           Data.Map.Strict             (singleton)
 import           Data.Maybe
 import           Data.Monoid                 ((<>))
@@ -24,13 +18,11 @@
 import           Data.Word
 import           Network.Haskoin.Address
 import           Network.Haskoin.Constants
-import           Network.Haskoin.Crypto
 import           Network.Haskoin.Keys
 import           Network.Haskoin.Script
 import           Network.Haskoin.Test
 import           Network.Haskoin.Transaction
 import           Network.Haskoin.Util
-import           Numeric                     (readHex)
 import           Test.Hspec
 import           Test.HUnit                  as HUnit
 import           Test.QuickCheck
@@ -96,7 +88,7 @@
             Right (RegularInput (SpendPK TxSignatureEmpty))
         let pk =
                 derivePubKeyI $
-                wrapSecKey True $ fromJust $ secKey $ BS.replicate 32 1
+                wrapSecKey True $ fromJust $ secKey $ B.replicate 32 1
         decodeInput net (Script [OP_0, opPushData $ S.encode pk]) `shouldBe`
             Right (RegularInput (SpendPKHash TxSignatureEmpty pk))
         decodeInput net (Script [OP_0, OP_0]) `shouldBe`
@@ -130,7 +122,7 @@
           -- We can disable specific tests by adding a DISABLED flag in the data
          ->
             unless ("DISABLED" `isInfixOf` flags) $ do
-                let strict =
+                let _strict =
                         "DERSIG" `isInfixOf` flags ||
                         "STRICTENC" `isInfixOf` flags ||
                         "NULLDUMMY" `isInfixOf` flags
@@ -181,7 +173,7 @@
                 "OK" -> ver `shouldBe` True
                 _    -> ver `shouldBe` False
 
-creditTx :: BS.ByteString -> Word64 -> Tx
+creditTx :: ByteString -> Word64 -> Tx
 creditTx scriptPubKey val =
     Tx 1 [txI] [txO] [] 0
   where
@@ -193,11 +185,11 @@
         , txInSequence = maxBound
         }
 
-spendTx :: BS.ByteString -> Word64 -> BS.ByteString -> Tx
+spendTx :: ByteString -> Word64 -> ByteString -> Tx
 spendTx scriptPubKey val scriptSig =
     Tx 1 [txI] [txO] [] 0
   where
-    txO = TxOut {outValue = val, scriptOutput = BS.empty}
+    txO = TxOut {outValue = val, scriptOutput = B.empty}
     txI =
         TxIn
         { prevOutput = OutPoint (txHash $ creditTx scriptPubKey val) 0
@@ -205,9 +197,9 @@
         , txInSequence = maxBound
         }
 
-parseScript :: String -> BS.ByteString
+parseScript :: String -> ByteString
 parseScript str =
-    BS.concat $ fromMaybe err $ mapM f $ words str
+    B.concat $ fromMaybe err $ mapM f $ words str
   where
     f = decodeHex . cs . dropHex . replaceToken
     dropHex ('0':'x':xs) = xs
@@ -254,7 +246,7 @@
                     eitherToMaybe . S.decode =<< decodeHex (cs scpStr)
                 sh = fromIntegral shI
                 res =
-                    eitherToMaybe . S.decode . BS.reverse =<<
+                    eitherToMaybe . S.decode . B.reverse =<<
                     decodeHex (cs resStr)
             Just (txSigHash net tx s 0 i sh) `shouldBe` res
 
@@ -285,10 +277,11 @@
     it "can read . show" $
         property $ forAll arbitrarySigHash $ \sh -> read (show sh) `shouldBe` sh
     it "can correctly show" $ do
-        show (0x00 :: SigHash) `shouldBe` "SigHash " <> show 0x00
-        show (0x01 :: SigHash) `shouldBe` "SigHash " <> show 0x01
-        show (0xff :: SigHash) `shouldBe` "SigHash " <> show 0xff
-        show (0xabac3344 :: SigHash) `shouldBe` "SigHash " <> show 0xabac3344
+        show (0x00 :: SigHash) `shouldBe` "SigHash " <> show (0x00 :: Word32)
+        show (0x01 :: SigHash) `shouldBe` "SigHash " <> show (0x01 :: Word32)
+        show (0xff :: SigHash) `shouldBe` "SigHash " <> show (0xff :: Word32)
+        show (0xabac3344 :: SigHash) `shouldBe` "SigHash " <>
+            show (0xabac3344 :: Word32)
     it "can add a forkid" $ do
         0x00 `sigHashAddForkId` 0x00 `shouldBe` 0x00
         0xff `sigHashAddForkId` 0x00ffffff `shouldBe` 0xffffffff
@@ -327,7 +320,7 @@
         isSigHashUnknown 0x04 `shouldBe` True
     it "can decodeTxSig . encode a TxSignature" $
         property $
-        forAll (arbitraryTxSignature net) $ \(_, _, ts@(TxSignature _ sh)) ->
+        forAll (arbitraryTxSignature net) $ \(_, _, ts) ->
             decodeTxSig net (encodeTxSig ts) `shouldBe` Right ts
     it "can produce the sighash one" $
         property $
@@ -351,69 +344,11 @@
 
 readTestFile :: A.FromJSON a => FilePath -> IO a
 readTestFile fp = do
-    bs <- BL.readFile $ "data/" <> fp <> ".json"
+    bs <- L.readFile $ "data/" <> fp <> ".json"
     maybe (error $ "Could not read test file " <> fp) return $ A.decode bs
 
 {- Parse tests from bitcoin-qt repository -}
 
-type ParseError = String
-
--- | Splits the JSON test into the different parts.  No processing,
--- just handling the fact that comments may not be there or might have
--- junk before it.  Output is the tuple ( sig, pubKey, flags, comment
--- ) as strings
-testParts :: [String] -> Maybe (String, String, String, String)
-testParts l =
-    let (x, r) = splitAt 3 l
-        comment =
-            if null r
-                then ""
-                else last r
-    in if length x < 3
-           then Nothing
-           else let [sig, pubKey, flags] = x
-                in Just (sig, pubKey, flags, comment)
-
--- | Maximum value of sequence number
-maxSeqNum :: Word32
-maxSeqNum = 0xffffffff -- Perhaps this should be moved to constants.
-
--- | Some of the scripts tests require transactions be built in a
--- standard way.  This function builds the crediting transaction.
--- Quoting the top comment of script_valid.json: "It is evaluated as
--- if there was a crediting coinbase transaction with two 0 pushes as
--- scriptSig, and one output of 0 satoshi and given scriptPubKey,
--- followed by a spending transaction which spends this output as only
--- input (and correct prevout hash), using the given scriptSig. All
--- nLockTimes are 0, all nSequences are max."
-buildCreditTx :: ByteString -> Tx
-buildCreditTx scriptPubKey =
-    Tx 1 [ txI ] [ txO ] [] 0
-  where
-    txO = TxOut { outValue = 0
-                , scriptOutput = scriptPubKey
-                }
-    txI = TxIn { prevOutput = nullOutPoint
-               , scriptInput = S.encode $ Script [ OP_0, OP_0 ]
-               , txInSequence = maxSeqNum
-               }
-
--- | Build a spending transaction for the tests.  Takes as input the
--- crediting transaction
-buildSpendTx :: ByteString  -- ScriptSig
-             -> Tx          -- Creditting Tx
-             -> Tx
-buildSpendTx scriptSig creditTx =
-    Tx 1 [ txI ] [ txO ] [] 0
-  where
-    txI = TxIn { prevOutput = OutPoint { outPointHash = txHash creditTx
-                                       , outPointIndex = 0
-                                       }
-               , scriptInput  = scriptSig
-               , txInSequence = maxSeqNum
-               }
-    txO = TxOut { outValue = 0, scriptOutput = BS.empty }
-
 mapMulSigVector :: ((Text, Text), Int) -> Spec
 mapMulSigVector (v, i) =
     it name $ runMulSigVector v
@@ -424,12 +359,12 @@
 runMulSigVector (a, ops) = assertBool "multisig vector" $ Just a == b
   where
     s = do
-        s <- decodeHex ops
-        eitherToMaybe $ S.decode s
+        s' <- decodeHex ops
+        eitherToMaybe $ S.decode s'
     b = do
         o <- s
         d <- eitherToMaybe $ decodeOutput o
-        addrToString $ p2shAddr btc d
+        return . addrToString $ payToScriptAddress btc d
 
 sigDecodeMap :: Network -> (Text, Int) -> Spec
 sigDecodeMap net (_, i) =
diff --git a/test/Network/Haskoin/TransactionSpec.hs b/test/Network/Haskoin/TransactionSpec.hs
--- a/test/Network/Haskoin/TransactionSpec.hs
+++ b/test/Network/Haskoin/TransactionSpec.hs
@@ -1,30 +1,18 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Network.Haskoin.TransactionSpec (spec) where
 
-import           Control.Monad               (forM_, unless, zipWithM_)
-import           Control.Monad.IO.Class
 import           Data.Aeson                  as A
-import           Data.Aeson.Types            as A
-import           Data.ByteString             (ByteString)
-import qualified Data.ByteString             as BS
-import qualified Data.ByteString.Lazy        as BL
-import           Data.Either                 (fromLeft, fromRight, isLeft,
-                                              isRight)
-import           Data.List                   (groupBy)
+import qualified Data.ByteString             as B
+import           Data.Either
 import           Data.Map.Strict             (singleton)
 import           Data.Maybe
 import           Data.Serialize              as S
-import           Data.Serialize.Get          (getWord32le, runGet)
-import           Data.Serialize.Put          (putWord32le, runPut)
 import           Data.String                 (fromString)
 import           Data.String.Conversions
 import           Data.Text                   (Text)
-import qualified Data.Vector                 as V
 import           Data.Word                   (Word32, Word64)
-import           GHC.Exts                    (IsString (..))
 import           Network.Haskoin.Address
 import           Network.Haskoin.Constants
-import           Network.Haskoin.Crypto
 import           Network.Haskoin.Keys
 import           Network.Haskoin.Script
 import           Network.Haskoin.Test
@@ -32,8 +20,7 @@
 import           Network.Haskoin.Util
 import           Safe                        (readMay)
 import           Test.Hspec
-import           Test.HUnit                  (Assertion, assertBool,
-                                              assertFailure)
+import           Test.HUnit                  (Assertion, assertBool)
 import           Test.QuickCheck
 
 spec :: Spec
@@ -41,9 +28,9 @@
     let net = btc
     describe "transaction unit tests" $ do
         it "compute txid from tx" $
-            zipWithM_ (curry mapTxIDVec) txIDVec [0 ..]
+            mapM_ runTxIDVec txIDVec
         it "build pkhash transaction (generated from bitcoind)" $
-            zipWithM_ (curry mapPKHashVec) pkHashVec [0 ..]
+            mapM_ runPKHashVec pkHashVec
         it "encode satoshi core script pubkey" tEncodeSatoshiCoreScriptPubKey
     describe "btc transaction" $ do
         it "decode and encode txid" $
@@ -90,9 +77,6 @@
 cerealID :: (Serialize a, Eq a) => a -> Bool
 cerealID x = S.decode (S.encode x) == Right x
 
-mapTxIDVec :: ((Text, Text), Int) -> Assertion
-mapTxIDVec (v,i) = runTxIDVec v
-
 runTxIDVec :: (Text, Text) -> Assertion
 runTxIDVec (tid, tx) = assertBool "txid" $ txHashToHex (txHash txBS) == tid
   where
@@ -114,10 +98,6 @@
       )
     ]
 
-mapPKHashVec :: (([(Text, Word32)], [(Text, Word64)], Text), Int)
-            -> Assertion
-mapPKHashVec (v, i) = runPKHashVec v
-
 runPKHashVec :: ([(Text, Word32)], [(Text, Word64)], Text) -> Assertion
 runPKHashVec (xs, ys, res) =
     assertBool "Build PKHash Tx" $ encodeHex (S.encode tx) == res
@@ -182,25 +162,15 @@
             Just i  -> encodeHex . S.encode . intToScriptOp $ i
             Nothing -> error $ "encodeSatoshiCoreScriptPubKey: " ++ s
 
-type TestComment = String
-
 {- Building Transactions -}
 
 testBuildAddrTx :: Network -> Address -> TestCoin -> Bool
-testBuildAddrTx net a (TestCoin v) =
-    case a of
-        PubKeyAddress h net -> Right (PayPKHash h) == out
-        ScriptAddress h net -> Right (PayScriptHash h) == out
+testBuildAddrTx net a (TestCoin v)
+    | isPubKeyAddress a = Right (PayPKHash (getAddrHash160 a)) == out
+    | isScriptAddress a = Right (PayScriptHash (getAddrHash160 a)) == out
+    | otherwise = undefined
   where
-    tx =
-        buildAddrTx
-            net
-            []
-            [ ( fromMaybe
-                    (error "Could not convert address to string")
-                    (addrToString a)
-              , v)
-            ]
+    tx = buildAddrTx net [] [(addrToString a, v)]
     out =
         decodeOutputBS $
         scriptOutput $
@@ -214,7 +184,7 @@
   where
     delta = pki + sum (map fst msi)
     guess = guessTxSize pki msi pkout msout
-    len = BS.length $ S.encode tx
+    len = B.length $ S.encode tx
     ins = map f $ txIn tx
     f i =
         fromRight (error "Could not decode input") $
@@ -267,10 +237,10 @@
   where
     txSigP =
         fromRight (error "Could not decode transaction") $
-        signTx net tx sigis (tail prv)
+        signTx net tx sigis (map secKeyData (tail prv))
     txSigC =
         fromRight (error "Could not decode transaction") $
-        signTx net txSigP sigis [head prv]
+        signTx net txSigP sigis [secKeyData (head prv)]
     verData = map (\(SigInput s v o _ _) -> (s, v, o)) sigis
 
 testMergeTx :: Network -> ([Tx], [(ScriptOutput, Word64, OutPoint, Int, Int)]) -> Bool