diff --git a/lib/cli/src/Cardano/CLI.hs b/lib/cli/src/Cardano/CLI.hs
index 1793c438c78..5f29fc0b151 100644
--- a/lib/cli/src/Cardano/CLI.hs
+++ b/lib/cli/src/Cardano/CLI.hs
@@ -958,6 +958,10 @@ data WalletClient t = WalletClient
     , postExternalTransaction
         :: PostExternalTransactionData
         -> ClientM ApiTxId
+    , deleteTransaction
+        :: ApiT WalletId
+        -> ApiTxId
+        -> ClientM NoContent
     , listPools
         :: ClientM [ApiStakePool]
     , networkInformation
@@ -986,6 +990,7 @@ walletClient =
             :<|> _listTransactions
             :<|> _postTransactionFee
             :<|> _postExternalTransaction
+            :<|> _deleteTransaction
             = transactions
 
         _listPools = pools
@@ -1003,6 +1008,7 @@ walletClient =
             , listTransactions = _listTransactions
             , postTransaction = _postTransaction
             , postExternalTransaction = _postExternalTransaction
+            , deleteTransaction = _deleteTransaction
             , postTransactionFee = _postTransactionFee
             , getWalletUtxoStatistics = _getWalletUtxoStatistics
             , listPools = _listPools
diff --git a/lib/core/src/Cardano/Wallet.hs b/lib/core/src/Cardano/Wallet.hs
index 8a4eb85a207..40089bdd47d 100644
--- a/lib/core/src/Cardano/Wallet.hs
+++ b/lib/core/src/Cardano/Wallet.hs
@@ -72,6 +72,7 @@ module Cardano.Wallet
     , updateWalletPassphrase
     , ErrWalletAlreadyExists (..)
     , ErrNoSuchWallet (..)
+    , ErrNoSuchTransaction (..)
     , ErrListUTxOStatistics (..)
     , ErrUpdatePassphrase (..)
 
@@ -81,6 +82,7 @@ module Cardano.Wallet
     -- ** Transaction
     , createUnsignedTx
     , estimateTxFee
+    , forgetPendingTx
     , listTransactions
     , signTx
     , submitExternalTx
@@ -93,6 +95,7 @@ module Cardano.Wallet
     , ErrCoinSelection (..)
     , ErrSubmitTx (..)
     , ErrSubmitExternalTx (..)
+    , ErrForgetPendingTx (..)
     , ErrPostTx (..)
     , ErrDecodeSignedTx (..)
     , ErrValidateSelection
@@ -110,6 +113,7 @@ import Cardano.BM.Trace
     ( Trace, logDebug, logInfo )
 import Cardano.Wallet.DB
     ( DBLayer
+    , ErrNoSuchTransaction (..)
     , ErrNoSuchWallet (..)
     , ErrWalletAlreadyExists (..)
     , PrimaryKey (..)
@@ -167,6 +171,7 @@ import Cardano.Wallet.Primitive.Types
     , Coin (..)
     , DefineTx (..)
     , Direction (..)
+    , Hash (..)
     , Range (..)
     , SlotId (..)
     , SlotParameters (..)
@@ -829,6 +834,17 @@ submitExternalTx ctx bytes = do
     nw = ctx ^. networkLayer @t
     tl = ctx ^. transactionLayer @t @k
 
+-- | Forget pending transaction.
+forgetPendingTx
+    :: forall ctx s t k.
+        ( HasDBLayer s t k ctx
+        , DefineTx t
+        )
+    => ctx
+    -> WalletId
+    -> Hash "Tx"
+    -> ExceptT ErrForgetPendingTx IO ()
+forgetPendingTx _ctx _wid _tid = undefined
 
 -- | List all transactions and metadata from history for a given wallet.
 listTransactions
@@ -1013,6 +1029,13 @@ data ErrSubmitExternalTx
     | ErrSubmitExternalTxDecode ErrDecodeSignedTx
     deriving (Show, Eq)
 
+-- | Errors that can occur when trying to change a wallet's passphrase.
+data ErrForgetPendingTx
+    = ErrForgetPendingTxNoSuchWallet ErrNoSuchWallet
+    | ErrForgetPendingTxNoSuchTransaction ErrNoSuchTransaction
+    | ErrForgetPendingTxTransactionIsNotPending (Hash "Tx")
+    deriving (Show, Eq)
+
 -- | Errors that can occur when trying to change a wallet's passphrase.
 data ErrUpdatePassphrase
     = ErrUpdatePassphraseNoSuchWallet ErrNoSuchWallet
diff --git a/lib/core/src/Cardano/Wallet/Api.hs b/lib/core/src/Cardano/Wallet/Api.hs
index e2e92be7f84..f0cd098979d 100644
--- a/lib/core/src/Cardano/Wallet/Api.hs
+++ b/lib/core/src/Cardano/Wallet/Api.hs
@@ -208,6 +208,7 @@ type Transactions t =
     :<|> ListTransactions t
     :<|> PostTransactionFee t
     :<|> PostExternalTransaction
+    :<|> DeleteTransaction
 
 -- | https://input-output-hk.github.io/cardano-wallet/api/#operation/postTransaction
 type CreateTransaction t = "wallets"
@@ -233,6 +234,13 @@ type ListTransactions t = "wallets"
     :> QueryParam "order" (ApiT SortOrder)
     :> Get '[JSON] [ApiTransaction t]
 
+-- | https://input-output-hk.github.io/cardano-wallet/api/#operation/deleteTransaction
+type DeleteTransaction = "wallets"
+    :> Capture "walletId" (ApiT WalletId)
+    :> "transactions"
+    :> Capture "transactionId" ApiTxId
+    :> DeleteNoContent '[Any] NoContent
+
 {-------------------------------------------------------------------------------
                                   StakePools
 
diff --git a/lib/core/src/Cardano/Wallet/Api/Server.hs b/lib/core/src/Cardano/Wallet/Api/Server.hs
index fbf413756d9..9bd725e6653 100644
--- a/lib/core/src/Cardano/Wallet/Api/Server.hs
+++ b/lib/core/src/Cardano/Wallet/Api/Server.hs
@@ -41,9 +41,11 @@ import Cardano.Wallet
     , ErrCreateUnsignedTx (..)
     , ErrDecodeSignedTx (..)
     , ErrEstimateTxFee (..)
+    , ErrForgetPendingTx (..)
     , ErrListTransactions (..)
     , ErrListUTxOStatistics (..)
     , ErrMkStdTx (..)
+    , ErrNoSuchTransaction (..)
     , ErrNoSuchWallet (..)
     , ErrPostTx (..)
     , ErrSignTx (..)
@@ -559,6 +561,7 @@ transactions ctx =
     :<|> listTransactions ctx
     :<|> postTransactionFee ctx
     :<|> postExternalTransaction ctx
+    :<|> deleteTransaction ctx
 
 postTransaction
     :: forall ctx s t k.
@@ -611,6 +614,22 @@ postExternalTransaction ctx (PostExternalTransactionData load) = do
     tx <- liftHandler $ W.submitExternalTx @ctx @t @k ctx load
     return $ ApiTxId (ApiT (txId @t tx))
 
+deleteTransaction
+    :: forall ctx s t k.
+        ( ctx ~ ApiLayer s t k
+        , DefineTx t
+        )
+    => ctx
+    -> ApiT WalletId
+    -> ApiTxId
+    -> Handler NoContent
+deleteTransaction ctx (ApiT wid) (ApiTxId (ApiT (tid))) = do
+    liftHandler $ withWorkerCtx ctx wid liftE $ \wrk ->
+        W.forgetPendingTx wrk wid tid
+    return NoContent
+  where
+    liftE = throwE . ErrForgetPendingTxNoSuchWallet
+
 listTransactions
     :: forall ctx s t k.
         ( DefineTx t
@@ -1079,6 +1098,14 @@ instance LiftHandler ErrNoSuchWallet where
                 , toText wid
                 ]
 
+instance LiftHandler ErrNoSuchTransaction where
+    handler = \case
+        ErrNoSuchTransaction tid ->
+            apiError err404 NoSuchTransaction $ mconcat
+                [ "I couldn't find a transaction with the given id: "
+                , toText tid
+                ]
+
 instance LiftHandler ErrWalletAlreadyExists where
     handler = \case
         ErrWalletAlreadyExists wid ->
@@ -1236,6 +1263,16 @@ instance LiftHandler ErrSubmitExternalTx where
             , errReasonPhrase = errReasonPhrase err400
             }
 
+instance LiftHandler ErrForgetPendingTx where
+    handler = \case
+        ErrForgetPendingTxNoSuchWallet e -> handler e
+        ErrForgetPendingTxNoSuchTransaction e -> handler e
+        ErrForgetPendingTxTransactionIsNotPending tid ->
+            apiError err404 TransactionNotPending $ mconcat
+                [ "The transaction with id : ", toText tid,
+                  " cannot be forgotten as it is not pending anymore."
+                ]
+
 instance LiftHandler ErrSubmitTx where
     handler = \case
         ErrSubmitTxNetwork e -> case e of
diff --git a/lib/core/src/Cardano/Wallet/Api/Types.hs b/lib/core/src/Cardano/Wallet/Api/Types.hs
index df7f1d651f1..c9928244a35 100644
--- a/lib/core/src/Cardano/Wallet/Api/Types.hs
+++ b/lib/core/src/Cardano/Wallet/Api/Types.hs
@@ -298,6 +298,8 @@ data ApiNetworkInformation = ApiNetworkInformation
 -- | Error codes returned by the API, in the form of snake_cased strings
 data ApiErrorCode
     = NoSuchWallet
+    | NoSuchTransaction
+    | TransactionNotPending
     | WalletAlreadyExists
     | NoRootKey
     | WrongEncryptionPassphrase
@@ -734,6 +736,14 @@ instance MimeUnrender OctetStream PostExternalTransactionData where
 instance MimeRender OctetStream PostExternalTransactionData where
    mimeRender _ (PostExternalTransactionData val) = BL.fromStrict val
 
+instance FromHttpApiData ApiTxId where
+    parseUrlPiece txt = case fromText txt of
+        Left (TextDecodingError err) -> Left $ T.pack err
+        Right tid -> Right $ ApiTxId $ ApiT tid
+
+instance ToHttpApiData ApiTxId where
+    toUrlPiece (ApiTxId (ApiT tid)) = toText tid
+
 {-------------------------------------------------------------------------------
                                 Aeson Options
 -------------------------------------------------------------------------------}
diff --git a/lib/core/src/Cardano/Wallet/DB.hs b/lib/core/src/Cardano/Wallet/DB.hs
index 4dc20973a8a..22ac90ce703 100644
--- a/lib/core/src/Cardano/Wallet/DB.hs
+++ b/lib/core/src/Cardano/Wallet/DB.hs
@@ -20,6 +20,7 @@ module Cardano.Wallet.DB
     , sparseCheckpoints
 
       -- * Errors
+    , ErrNoSuchTransaction (..)
     , ErrNoSuchWallet(..)
     , ErrWalletAlreadyExists(..)
     ) where
@@ -185,6 +186,11 @@ newtype ErrNoSuchWallet
     = ErrNoSuchWallet WalletId -- Wallet is gone or doesn't exist yet
     deriving (Eq, Show)
 
+-- | Can't perform given operation because there's no transaction
+newtype ErrNoSuchTransaction
+    = ErrNoSuchTransaction (Hash "Tx")
+    deriving (Eq, Show)
+
 -- | Forbidden operation was executed on an already existing wallet
 newtype ErrWalletAlreadyExists
     = ErrWalletAlreadyExists WalletId -- Wallet already exists in db
diff --git a/lib/core/src/Cardano/Wallet/DaedalusIPC.hs b/lib/core/src/Cardano/Wallet/DaedalusIPC.hs
index 60e696f94bb..922430d0209 100644
--- a/lib/core/src/Cardano/Wallet/DaedalusIPC.hs
+++ b/lib/core/src/Cardano/Wallet/DaedalusIPC.hs
@@ -63,7 +63,7 @@ import GHC.IO.Handle.FD
 import System.Environment
     ( lookupEnv )
 import System.Info
-    ( arch )
+    ( os )
 import System.IO
     ( Handle, hFlush, hGetLine, hSetNewlineMode, noNewlineTranslation )
 import System.IO.Error
@@ -214,7 +214,7 @@ readMessage :: Handle -> IO BL.ByteString
 readMessage = if isWindows then windowsReadMessage else posixReadMessage
 
 isWindows :: Bool
-isWindows = arch == "windows"
+isWindows = os == "windows"
 
 windowsReadMessage :: Handle -> IO BL.ByteString
 windowsReadMessage handle = do
diff --git a/lib/jormungandr/src/Cardano/Wallet/Jormungandr.hs b/lib/jormungandr/src/Cardano/Wallet/Jormungandr.hs
index 6038a20252a..801100ad572 100644
--- a/lib/jormungandr/src/Cardano/Wallet/Jormungandr.hs
+++ b/lib/jormungandr/src/Cardano/Wallet/Jormungandr.hs
@@ -97,6 +97,7 @@ import System.Exit
 import qualified Cardano.BM.Configuration.Model as CM
 import qualified Cardano.Wallet.Api.Server as Server
 import qualified Cardano.Wallet.DB.Sqlite as Sqlite
+import qualified Cardano.Wallet.Jormungandr.Binary as J
 import qualified Data.Text as T
 import qualified Network.Wai.Handler.Warp as Warp
 
@@ -128,21 +129,21 @@ serveWallet (cfg, sb, tr) databaseDir listen lj beforeMainLoop = do
             let nPort = Port $ baseUrlPort $ _restApi cp
             waitForService "Jörmungandr" (sb, tr) nPort $
                 waitForNetwork nl defaultRetryPolicy
-            rndApi <- apiLayer tr nl
-            seqApi <- apiLayer tr nl
-            startServer tr nPort nl rndApi seqApi
+            let (_, bp) = staticBlockchainParameters nl
+            rndApi <- apiLayer tr (toWLBlock <$> nl)
+            seqApi <- apiLayer tr (toWLBlock <$> nl)
+            startServer tr nPort bp rndApi seqApi
             pure ExitSuccess
         Left e -> handleNetworkStartupError e
   where
     startServer
         :: Trace IO Text
         -> Port "node"
-        -> NetworkLayer IO t (Block Tx)
+        -> BlockchainParameters
         -> ApiLayer (RndState t) t RndKey
         -> ApiLayer (SeqState t) t SeqKey
         -> IO ()
-    startServer tracer nPort nl rndWallet seqWallet = do
-        let (_, bp) = staticBlockchainParameters nl
+    startServer tracer nPort bp rndWallet seqWallet = do
         Server.withListeningSocket listen $ \(wPort, socket) -> do
             let tracerIPC = appendName "daedalus-ipc" tracer
             let tracerApi = appendName "api" tracer
@@ -153,6 +154,8 @@ serveWallet (cfg, sb, tr) databaseDir listen lj beforeMainLoop = do
                     Server.start settings tracerApi socket rndWallet seqWallet
             race_ ipcServer apiServer
 
+    toWLBlock = J.convertBlock
+
     apiLayer
         :: forall s k .
             ( KeyToAddress (Jormungandr 'Testnet) k
diff --git a/lib/jormungandr/src/Cardano/Wallet/Jormungandr/Network.hs b/lib/jormungandr/src/Cardano/Wallet/Jormungandr/Network.hs
index 364c989a7be..8ed2d43102d 100644
--- a/lib/jormungandr/src/Cardano/Wallet/Jormungandr/Network.hs
+++ b/lib/jormungandr/src/Cardano/Wallet/Jormungandr/Network.hs
@@ -29,6 +29,7 @@ module Cardano.Wallet.Jormungandr.Network
       JormungandrBackend (..)
     , JormungandrConnParams (..)
     , withNetworkLayer
+    , newNetworkLayer
 
     -- * Launching the node backend
     , JormungandrConfig (..)
@@ -86,7 +87,7 @@ import Cardano.Wallet.Jormungandr.Api.Client
     , postMessage
     )
 import Cardano.Wallet.Jormungandr.Binary
-    ( convertBlock, runGetOrFail )
+    ( runGetOrFail )
 import Cardano.Wallet.Jormungandr.BlockHeaders
     ( BlockHeaders (..)
     , appendBlockHeaders
@@ -100,8 +101,6 @@ import Cardano.Wallet.Jormungandr.BlockHeaders
     )
 import Cardano.Wallet.Jormungandr.Compatibility
     ( Jormungandr, genConfigFile, localhostBaseUrl )
-import Cardano.Wallet.Jormungandr.Primitive.Types
-    ( Tx )
 import Cardano.Wallet.Network
     ( Cursor, NetworkLayer (..), NextBlocksResult (..), defaultRetryPolicy )
 import Cardano.Wallet.Network.Ports
@@ -109,7 +108,7 @@ import Cardano.Wallet.Network.Ports
 import Cardano.Wallet.Primitive.Model
     ( BlockchainParameters (..) )
 import Cardano.Wallet.Primitive.Types
-    ( Block (..), BlockHeader (..), Hash (..), SlotId (..) )
+    ( BlockHeader (..), Hash (..), SlotId (..) )
 import Control.Concurrent.MVar.Lifted
     ( MVar, modifyMVar, newMVar, readMVar )
 import Control.Exception
@@ -179,7 +178,7 @@ withNetworkLayer
     -- ^ Logging
     -> JormungandrBackend
     -- ^ How Jörmungandr is started.
-    -> (Either ErrStartup (JormungandrConnParams, NetworkLayer IO t (Block Tx)) -> IO a)
+    -> (Either ErrStartup (JormungandrConnParams, NetworkLayer IO t J.Block) -> IO a)
     -- ^ The action to run. It will be passed the connection parameters used,
     -- and a network layer if startup was successful.
     -> IO a
@@ -192,7 +191,7 @@ withNetworkLayerLaunch
     -- ^ Logging of node startup.
     -> JormungandrConfig
     -- ^ Configuration for starting Jörmungandr.
-    -> (Either ErrStartup (JormungandrConnParams, NetworkLayer IO t (Block Tx)) -> IO a)
+    -> (Either ErrStartup (JormungandrConnParams, NetworkLayer IO t J.Block) -> IO a)
     -- ^ The action to run. It will be passed the connection parameters used,
     -- and a network layer if startup was successful.
     -> IO a
@@ -204,7 +203,7 @@ withNetworkLayerConn
     :: forall n a t. (t ~ Jormungandr n)
     => JormungandrConnParams
     -- ^ Parameters for connecting to Jörmungandr node which is already running.
-    -> (Either ErrStartup (JormungandrConnParams, NetworkLayer IO t (Block Tx)) -> IO a)
+    -> (Either ErrStartup (JormungandrConnParams, NetworkLayer IO t J.Block) -> IO a)
     -- ^ Action to run with the network layer.
     -> IO a
 withNetworkLayerConn cp@(JormungandrConnParams block0H baseUrl) action =
@@ -219,13 +218,13 @@ newNetworkLayer
     :: forall n t. (t ~ Jormungandr n)
     => BaseUrl
     -> Hash "Genesis"
-    -> ExceptT ErrGetBlockchainParams IO (NetworkLayer IO t (Block Tx))
+    -> ExceptT ErrGetBlockchainParams IO (NetworkLayer IO t J.Block)
 newNetworkLayer baseUrl block0H = do
     mgr <- liftIO $ newManager defaultManagerSettings
     st <- newMVar emptyBlockHeaders
     let jor = mkJormungandrClient mgr baseUrl
     g0 <- getInitialBlockchainParameters jor (coerce block0H)
-    return (convertBlock <$> mkRawNetworkLayer g0 st jor)
+    return (mkRawNetworkLayer g0 st jor)
 
 -- | Wrap a Jormungandr client into a 'NetworkLayer' common interface.
 --
diff --git a/specifications/api/swagger.yaml b/specifications/api/swagger.yaml
index d32ca71b9eb..0ec21effd15 100644
--- a/specifications/api/swagger.yaml
+++ b/specifications/api/swagger.yaml
@@ -674,6 +674,15 @@ x-parametersWalletId: &parametersWalletId
   maxLength: 40
   minLength: 40
 
+x-parametersTransactionId: &parametersTransactionId
+  in: path
+  name: transactionId
+  required: true
+  type: string
+  format: hex
+  maxLength: 64
+  minLength: 64
+
 x-parametersStakePoolId: &parametersStakePoolId
   in: path
   name: stakePoolId
@@ -866,6 +875,16 @@ x-responsesPutWalletPassphrase: &responsesPutWalletPassphrase
   204:
     description: No Content
 
+x-responsesDeleteTransaction: &responsesDeleteTransaction
+  <<: *responsesErr400
+  <<: *responsesErr403
+  <<: *responsesErr404
+  <<: *responsesErr405
+  <<: *responsesErr406
+  <<: *responsesErr415
+  204:
+    description: No Content
+
 x-responsesListTransactions: &responsesListTransactions
   <<: *responsesErr404
   <<: *responsesErr405
@@ -1155,6 +1174,20 @@ paths:
           schema: *ApiPostTransactionFeeData
       responses: *responsesPostTransactionFee
 
+  /wallets/{walletId}/transactions/{transactionId}:
+    delete:
+      operationId: deleteTransaction
+      tags: ["Transactions"]
+      summary: Delete
+      description: |
+        <p align="right">status: <strong>under development</strong></p>
+
+        Forget pending transaction.
+      parameters:
+        - *parametersWalletId
+        - *parametersTransactionId
+      responses: *responsesDeleteTransaction
+
   /wallets/{walletId}/addresses:
     get:
       operationId: listAddresses