From a19cdfe31b072e3dcd92a240d27bd0153370e108 Mon Sep 17 00:00:00 2001
From: Johannes Lund <johannes.lund@iohk.io>
Date: Wed, 4 Dec 2019 10:18:17 +0100
Subject: [PATCH 1/6] Remove redundant constraint

---
 .../test/unit/Cardano/Wallet/Jormungandr/TransactionSpec.hs   | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/jormungandr/test/unit/Cardano/Wallet/Jormungandr/TransactionSpec.hs b/lib/jormungandr/test/unit/Cardano/Wallet/Jormungandr/TransactionSpec.hs
index 8e5a6b3fa7e..fc2ef179d06 100644
--- a/lib/jormungandr/test/unit/Cardano/Wallet/Jormungandr/TransactionSpec.hs
+++ b/lib/jormungandr/test/unit/Cardano/Wallet/Jormungandr/TransactionSpec.hs
@@ -13,8 +13,6 @@ module Cardano.Wallet.Jormungandr.TransactionSpec
 
 import Prelude
 
-import Cardano.Wallet.Jormungandr.Compatibility
-    ( Jormungandr )
 import Cardano.Wallet.Jormungandr.Transaction
     ( ErrExceededInpsOrOuts (..), newTransactionLayer )
 import Cardano.Wallet.Primitive.AddressDerivation
@@ -509,7 +507,7 @@ goldenTestStdTx tl keystore inps outs bytes' = it title $ do
     title = "golden test mkStdTx: " <> show inps <> show outs
 
 goldenTestDelegationCertTx
-    :: forall t k. (t ~ Jormungandr, HasCallStack)
+    :: forall t k. (HasCallStack)
     => TransactionLayer t k
     -> (Address -> Maybe (k 'AddressK XPrv, Passphrase "encryption"))
     -> PoolId

From 13448156b1c5451f7a12793318bda34c9277584e Mon Sep 17 00:00:00 2001
From: Johannes Lund <johannes.lund@iohk.io>
Date: Thu, 5 Dec 2019 14:46:32 +0100
Subject: [PATCH 2/6] Fix incorrect swagger schema for tx fee estimation

---
 specifications/api/swagger.yaml | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/specifications/api/swagger.yaml b/specifications/api/swagger.yaml
index 22c04a97a9e..cf70e742d0a 100644
--- a/specifications/api/swagger.yaml
+++ b/specifications/api/swagger.yaml
@@ -1042,11 +1042,7 @@ x-responsesPostTransactionFee: &responsesPostTransactionFee
   200:
     description: Ok
     schema:
-      type: object
-      required:
-        - amount
-      properties:
-        amount: *ApiFee
+      <<: *ApiFee
 
 x-responsesListAddresses: &responsesListAddresses
   <<: *responsesErr400

From 754a1c7e81ba0daca718789667097d53694e03e3 Mon Sep 17 00:00:00 2001
From: Johannes Lund <johannes.lund@iohk.io>
Date: Thu, 5 Dec 2019 14:44:28 +0100
Subject: [PATCH 3/6] Add /stake-pools/{pid}/wallets/{wid}/fee to swagger.yaml

---
 specifications/api/swagger.yaml | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/specifications/api/swagger.yaml b/specifications/api/swagger.yaml
index cf70e742d0a..f85276ac667 100644
--- a/specifications/api/swagger.yaml
+++ b/specifications/api/swagger.yaml
@@ -1044,6 +1044,15 @@ x-responsesPostTransactionFee: &responsesPostTransactionFee
     schema:
       <<: *ApiFee
 
+x-responsesGetJoinStakePoolFee: &responsesGetJoinStakePoolFee
+  <<: *responsesErr404
+  <<: *responsesErr405
+  <<: *responsesErr406
+  200:
+    description: Ok
+    schema:
+        <<: *ApiFee
+
 x-responsesListAddresses: &responsesListAddresses
   <<: *responsesErr400
   <<: *responsesErr404
@@ -1336,6 +1345,20 @@ paths:
           schema: *parametersQuitStakePool
       responses: *responsesQuitStakePool
 
+  /stake-pools/{stakePoolId}/wallets/{walletId}/fee:
+    get:
+      operationId: joinStakePoolFee
+      tags: ["Stake Pools"]
+      summary: Estimate
+      description: |
+        <p align="right">status: <strong>stable</strong></p>
+
+        Estimate fee for joining a stake pool.
+      parameters:
+        - *parametersStakePoolId
+        - *parametersWalletId
+      responses: *responsesGetJoinStakePoolFee
+
   /byron-wallets:
     get:
       operationId: listByronWallets

From e98f33f2f3689d841e52ad8f2fd09a56fdbb0782 Mon Sep 17 00:00:00 2001
From: Johannes Lund <johannes.lund@iohk.io>
Date: Thu, 5 Dec 2019 11:54:52 +0100
Subject: [PATCH 4/6] Add feeBalance :: CoinSelection -> Word64

---
 lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs b/lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs
index e2bc725e7e6..5c3fc1f2e51 100644
--- a/lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs
+++ b/lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs
@@ -92,6 +92,9 @@ outputBalance = foldl' addTxOut 0 . outputs
 changeBalance :: CoinSelection -> Word64
 changeBalance = foldl' addCoin 0 . change
 
+feeBalance :: CoinSelection -> Word64
+feeBalance sel = inputBalance sel - outputBalance sel - changeBalance sel
+
 addTxOut :: Integral a => a -> TxOut -> a
 addTxOut total = addCoin total . coin
 

From 402c67fb3ce7d631b55919897dae34372912c278 Mon Sep 17 00:00:00 2001
From: Johannes Lund <johannes.lund@iohk.io>
Date: Wed, 4 Dec 2019 10:18:00 +0100
Subject: [PATCH 5/6] Add estimate join-stake-pool fee endpoint

---
 lib/cli/src/Cardano/CLI.hs                    |  1 +
 .../src/Test/Integration/Framework/DSL.hs     | 21 +++++++
 .../Test/Integration/Framework/TestData.hs    | 21 +++++++
 lib/core/src/Cardano/Wallet/Api.hs            | 10 ++++
 lib/core/src/Cardano/Wallet/Api/Server.hs     | 24 +++++++-
 .../Cardano/Wallet/Primitive/CoinSelection.hs |  1 +
 .../Jormungandr/Scenario/API/StakePools.hs    | 58 ++++++++++++++++++-
 7 files changed, 134 insertions(+), 2 deletions(-)

diff --git a/lib/cli/src/Cardano/CLI.hs b/lib/cli/src/Cardano/CLI.hs
index bbaa18a5d3d..df10946eb1e 100644
--- a/lib/cli/src/Cardano/CLI.hs
+++ b/lib/cli/src/Cardano/CLI.hs
@@ -1120,6 +1120,7 @@ walletClient =
 
         _listPools
             :<|> _joinStakePool
+            :<|> _joinStakePoolFee
             :<|> _quitStakePool
             = pools
 
diff --git a/lib/core-integration/src/Test/Integration/Framework/DSL.hs b/lib/core-integration/src/Test/Integration/Framework/DSL.hs
index a80fa1797cd..35a4bd94e32 100644
--- a/lib/core-integration/src/Test/Integration/Framework/DSL.hs
+++ b/lib/core-integration/src/Test/Integration/Framework/DSL.hs
@@ -86,6 +86,7 @@ module Test.Integration.Framework.DSL
     , getFromResponseList
     , json
     , joinStakePool
+    , joinStakePoolFee
     , quitStakePool
     , listAddresses
     , listTransactions
@@ -123,6 +124,7 @@ module Test.Integration.Framework.DSL
     , getAddressesEp
     , listStakePoolsEp
     , joinStakePoolEp
+    , joinStakePoolFeeEp
     , quitStakePoolEp
     , stakePoolEp
     , postTxEp
@@ -162,6 +164,7 @@ import Cardano.Wallet.Api.Types
     , ApiByronWallet
     , ApiByronWalletBalance
     , ApiEpochInfo
+    , ApiFee
     , ApiStakePoolMetrics
     , ApiT (..)
     , ApiTransaction
@@ -1154,6 +1157,15 @@ quitStakePool ctx p (w, pass) = do
             } |]
     request @(ApiTransaction 'Testnet) ctx (quitStakePoolEp p w) Default payload
 
+joinStakePoolFee
+    :: forall t w. (HasType (ApiT WalletId) w)
+    => Context t
+    -> ApiT PoolId
+    -> w
+    -> IO (HTTP.Status, Either RequestException ApiFee)
+joinStakePoolFee ctx p w = do
+    request @ApiFee ctx (joinStakePoolFeeEp p w) Default Empty
+
 listAddresses
     :: Context t
     -> ApiWallet
@@ -1352,6 +1364,15 @@ joinStakePoolEp
     -> (Method, Text)
 joinStakePoolEp = stakePoolEp "PUT"
 
+joinStakePoolFeeEp
+    :: forall w. (HasType (ApiT WalletId) w)
+    => ApiT PoolId
+    -> w
+    -> (Method, Text)
+joinStakePoolFeeEp pid w = (verb, path <> "/fee")
+    where
+       (verb, path) = stakePoolEp "GET" pid w
+
 quitStakePoolEp
     :: forall w. (HasType (ApiT WalletId) w)
     => ApiT PoolId
diff --git a/lib/core-integration/src/Test/Integration/Framework/TestData.hs b/lib/core-integration/src/Test/Integration/Framework/TestData.hs
index f708e28d54e..b6fff524112 100644
--- a/lib/core-integration/src/Test/Integration/Framework/TestData.hs
+++ b/lib/core-integration/src/Test/Integration/Framework/TestData.hs
@@ -32,6 +32,10 @@ module Test.Integration.Framework.TestData
     , russianWalletName
     , wildcardsWalletName
 
+    -- * Stake pool ids
+    , nonExistingStakePool1
+    , invalidPoolIds
+
     -- * Helpers
     , addressPoolGapMax
     , addressPoolGapMin
@@ -266,6 +270,23 @@ wildcardsWalletName :: Text
 wildcardsWalletName = "`~`!@#$%^&*()_+-=<>,./?;':\"\"'{}[]\\|❤️ 💔 💌 💕 💞 \
 \💓 💗 💖 💘 💝 💟 💜 💛 💚 💙0️⃣ 1️⃣ 2️⃣ 3️⃣ 4️⃣ 5️⃣ 6️⃣ 7️⃣ 8️⃣ 9️⃣ 🔟🇺🇸🇷🇺🇸 🇦🇫🇦🇲🇸"
 
+
+--
+-- Stake Pools
+--
+
+nonExistingStakePool1 :: Text
+nonExistingStakePool1 = "008d686a02c6e625b5a59cc9e234f32e5d72987012f9c25c9a6b60ddade197d1"
+
+invalidPoolIds :: [(String, String)]
+invalidPoolIds =
+        [ ("64 chars non-hex", replicate 64 'ś')
+        , ("63 chars hex", replicate 63 '1')
+        , ("65 chars hex", replicate 65 '1')
+        , ("64 chars hex", replicate 64 '1')
+        , ("empty", "")
+        ]
+
 ---
 --- Helpers
 ---
diff --git a/lib/core/src/Cardano/Wallet/Api.hs b/lib/core/src/Cardano/Wallet/Api.hs
index b3e7eb64f75..feab779d93e 100644
--- a/lib/core/src/Cardano/Wallet/Api.hs
+++ b/lib/core/src/Cardano/Wallet/Api.hs
@@ -138,6 +138,7 @@ type CoreApi t =
 type StakePoolApi t =
     ListStakePools
     :<|> JoinStakePool t
+    :<|> JoinStakePoolFee
     :<|> QuitStakePool t
 
 type CompatibilityApi n =
@@ -282,6 +283,15 @@ type JoinStakePool t = "stake-pools"
     :> ReqBody '[JSON] ApiWalletPassphrase
     :> PutAcccepted '[JSON] (ApiTransaction t)
 
+
+-- | https://input-output-hk.github.io/cardano-wallet/api/#operation/joinStakePool
+type JoinStakePoolFee = "stake-pools"
+    :> Capture "stakePoolId" (ApiT PoolId)
+    :> "wallets"
+    :> Capture "walletId" (ApiT WalletId)
+    :> "fee"
+    :> Get '[JSON] ApiFee
+
 -- | https://input-output-hk.github.io/cardano-wallet/api/#operation/quitStakePool
 type QuitStakePool t = "stake-pools"
     :> Capture "stakePoolId" (ApiT PoolId)
diff --git a/lib/core/src/Cardano/Wallet/Api/Server.hs b/lib/core/src/Cardano/Wallet/Api/Server.hs
index ada9f4ab76b..064d4a80685 100644
--- a/lib/core/src/Cardano/Wallet/Api/Server.hs
+++ b/lib/core/src/Cardano/Wallet/Api/Server.hs
@@ -149,7 +149,7 @@ import Cardano.Wallet.Primitive.AddressDiscovery.Random
 import Cardano.Wallet.Primitive.AddressDiscovery.Sequential
     ( SeqState (..), defaultAddressPoolGap, mkSeqState )
 import Cardano.Wallet.Primitive.CoinSelection
-    ( CoinSelection, changeBalance, inputBalance )
+    ( CoinSelection, changeBalance, feeBalance, inputBalance )
 import Cardano.Wallet.Primitive.Fee
     ( Fee (..) )
 import Cardano.Wallet.Primitive.Model
@@ -787,6 +787,7 @@ stakePools
 stakePools ctx spl =
     listPools spl
     :<|> joinStakePool ctx spl
+    :<|> joinStakePoolFee ctx spl
     :<|> quitStakePool ctx
 
 listPools
@@ -837,6 +838,27 @@ joinStakePool ctx spl (ApiT pid) (ApiT wid) (ApiWalletPassphrase (ApiT pwd)) = d
   where
     liftE = throwE . ErrJoinStakePoolNoSuchWallet
 
+joinStakePoolFee
+    :: forall ctx s t n k.
+        ( DelegationAddress n k
+        , Buildable (ErrValidateSelection t)
+        , s ~ SeqState n k
+        , k ~ ShelleyKey
+        , HardDerivation k
+        , ctx ~ ApiLayer s t k
+        )
+    => ctx
+    -> StakePoolLayer IO
+    -> ApiT PoolId
+    -> ApiT WalletId
+    -> Handler ApiFee
+joinStakePoolFee ctx _spl (ApiT _pid) (ApiT wid) = do
+    liftHandler $ withWorkerCtx ctx wid liftE $ \wrk ->
+         apiFee <$> W.selectCoinsForDelegation @_ @s @t @k wrk wid
+  where
+    apiFee = ApiFee . Quantity . fromIntegral . feeBalance
+    liftE = throwE . ErrSelectForDelegationNoSuchWallet
+
 quitStakePool
     :: forall ctx s t n k.
         ( DelegationAddress n k
diff --git a/lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs b/lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs
index 5c3fc1f2e51..a42f65d4f10 100644
--- a/lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs
+++ b/lib/core/src/Cardano/Wallet/Primitive/CoinSelection.hs
@@ -19,6 +19,7 @@ module Cardano.Wallet.Primitive.CoinSelection
     , inputBalance
     , outputBalance
     , changeBalance
+    , feeBalance
     , ErrCoinSelection (..)
     , CoinSelectionOptions (..)
     ) where
diff --git a/lib/jormungandr/test/integration/Test/Integration/Jormungandr/Scenario/API/StakePools.hs b/lib/jormungandr/test/integration/Test/Integration/Jormungandr/Scenario/API/StakePools.hs
index 6ea620476b9..719b58a9e62 100644
--- a/lib/jormungandr/test/integration/Test/Integration/Jormungandr/Scenario/API/StakePools.hs
+++ b/lib/jormungandr/test/integration/Test/Integration/Jormungandr/Scenario/API/StakePools.hs
@@ -13,7 +13,8 @@ module Test.Integration.Jormungandr.Scenario.API.StakePools
 import Prelude
 
 import Cardano.Wallet.Api.Types
-    ( ApiNetworkInformation
+    ( ApiFee
+    , ApiNetworkInformation
     , ApiStakePool
     , ApiT (..)
     , ApiTransaction
@@ -40,6 +41,7 @@ import Test.Integration.Framework.DSL
     , Headers (..)
     , Payload (..)
     , TxDescription (..)
+    , amount
     , apparentPerformance
     , balanceAvailable
     , balanceReward
@@ -61,6 +63,7 @@ import Test.Integration.Framework.DSL
     , expectResponseCode
     , faucetUtxoAmt
     , feeEstimator
+    , fixtureByronWallet
     , fixturePassphrase
     , fixtureWallet
     , fixtureWalletWith
@@ -68,6 +71,8 @@ import Test.Integration.Framework.DSL
     , getWalletEp
     , joinStakePool
     , joinStakePoolEp
+    , joinStakePoolFee
+    , joinStakePoolFeeEp
     , json
     , listStakePoolsEp
     , listTxEp
@@ -81,16 +86,21 @@ import Test.Integration.Framework.DSL
     , status
     , unsafeRequest
     , verify
+    , walletId
     )
 import Test.Integration.Framework.TestData
     ( errMsg403DelegationFee
     , errMsg403PoolAlreadyJoined
     , errMsg403WrongPass
     , errMsg403WrongPool
+    , errMsg404NoEndpoint
     , errMsg404NoSuchPool
+    , errMsg404NoWallet
     , errMsg405
     , errMsg406
     , errMsg415
+    , falseWalletIds
+    , invalidPoolIds
     , passphraseMaxLength
     , passphraseMinLength
     )
@@ -503,6 +513,52 @@ spec = do
         r <- joinStakePool ctx (p ^. #id) (w, "Secure Passprase")
         expectResponseCode HTTP.status404 r
 
+    it "STAKE_POOLS_ESTIMATE_FEE_01 - fee matches eventual cost" $ \ctx -> do
+        (_, p:_) <- eventually $
+            unsafeRequest @[ApiStakePool] ctx listStakePoolsEp Empty
+        w <- fixtureWallet ctx
+        fee <- getFromResponse amount <$> joinStakePoolFee ctx (p ^. #id) w
+        r <- joinStakePool ctx (p ^. #id) (w, fixturePassphrase)
+        verify r
+            [ expectFieldEqual amount fee
+            ]
+
+    it "STAKE_POOLS_ESTIMATE_FEE_02 - \
+        \empty wallet cannot estimate fee" $ \ctx -> do
+        (_, p:_) <- eventually $
+            unsafeRequest @[ApiStakePool] ctx listStakePoolsEp Empty
+        w <- emptyWallet ctx
+        joinStakePoolFee ctx (p ^. #id) w >>= flip verify
+            [ expectResponseCode HTTP.status403
+            , expectErrorMessage $ errMsg403DelegationFee stakeDelegationFee
+            ]
+
+    it "STAKE_POOLS_ESTIMATE_FEE_03 - can't use byron wallets" $ \ctx -> do
+        (_, p:_) <- eventually $
+            unsafeRequest @[ApiStakePool] ctx listStakePoolsEp Empty
+        w <- fixtureByronWallet ctx
+        let ep = joinStakePoolFeeEp (p ^. #id) w
+        r <- request @(ApiTransaction 'Mainnet) ctx ep Default Empty
+        verify r
+            [ expectResponseCode HTTP.status404 -- should fail
+            , expectErrorMessage $ errMsg404NoWallet (w ^. walletId)
+            ]
+
+    describe "STAKE_POOLS_ESTIMATE_FEE_04 - invalid pool and wallet ids" $ do
+        forM_ invalidPoolIds $ \(pDesc, poolId) ->
+            forM_ falseWalletIds $ \(wDesc, walId) -> do
+            let path = poolId <> "/wallets/" <> walId
+            it ("pool:" ++ pDesc ++ ", wallet:" ++ wDesc) $ \ctx -> do
+                let endpoint = "v2/stake-pools/"
+                                <> T.pack path
+                                <> "/fee"
+                rg <- request @ApiFee ctx ("GET", endpoint)
+                    Default Empty
+                expectResponseCode @IO HTTP.status404 rg
+                if pDesc == "64 chars hex" && wDesc == "40 chars hex"
+                then expectErrorMessage (errMsg404NoWallet $ T.pack walId) rg
+                else expectErrorMessage errMsg404NoEndpoint rg
+
     describe "STAKE_POOLS_JOIN/QUIT_05 - Bad request" $ do
         let verifyIt ctx sPoolEndp = do
                 w <- emptyWallet ctx

From decdad3e649ae9278d47815926d729ee56e25941 Mon Sep 17 00:00:00 2001
From: KtorZ <matthias.benkort@gmail.com>
Date: Mon, 9 Dec 2019 16:21:29 +0100
Subject: [PATCH 6/6] adjust according to review comments

- remove the pool id parameter from the endpoint
- use fee estimator in the tests
- rename 'joinStakePoolFee' to 'delegationFee'
---
 lib/cli/src/Cardano/CLI.hs                    |  3 +-
 .../src/Test/Integration/Framework/DSL.hs     | 24 +++++------
 .../Test/Integration/Framework/TestData.hs    | 20 ---------
 lib/core/src/Cardano/Wallet/Api.hs            | 11 +++--
 lib/core/src/Cardano/Wallet/Api/Server.hs     |  8 ++--
 .../Jormungandr/Scenario/API/StakePools.hs    | 42 +++++++++----------
 specifications/api/swagger.yaml               | 26 +++++++-----
 7 files changed, 56 insertions(+), 78 deletions(-)

diff --git a/lib/cli/src/Cardano/CLI.hs b/lib/cli/src/Cardano/CLI.hs
index df10946eb1e..d1c021cf2b8 100644
--- a/lib/cli/src/Cardano/CLI.hs
+++ b/lib/cli/src/Cardano/CLI.hs
@@ -1120,11 +1120,10 @@ walletClient =
 
         _listPools
             :<|> _joinStakePool
-            :<|> _joinStakePoolFee
             :<|> _quitStakePool
+            :<|> _delegationFee
             = pools
 
-
         _networkInformation = network
     in
         WalletClient
diff --git a/lib/core-integration/src/Test/Integration/Framework/DSL.hs b/lib/core-integration/src/Test/Integration/Framework/DSL.hs
index 35a4bd94e32..aac0a349570 100644
--- a/lib/core-integration/src/Test/Integration/Framework/DSL.hs
+++ b/lib/core-integration/src/Test/Integration/Framework/DSL.hs
@@ -86,7 +86,7 @@ module Test.Integration.Framework.DSL
     , getFromResponseList
     , json
     , joinStakePool
-    , joinStakePoolFee
+    , delegationFee
     , quitStakePool
     , listAddresses
     , listTransactions
@@ -124,7 +124,7 @@ module Test.Integration.Framework.DSL
     , getAddressesEp
     , listStakePoolsEp
     , joinStakePoolEp
-    , joinStakePoolFeeEp
+    , delegationFeeEp
     , quitStakePoolEp
     , stakePoolEp
     , postTxEp
@@ -1157,14 +1157,13 @@ quitStakePool ctx p (w, pass) = do
             } |]
     request @(ApiTransaction 'Testnet) ctx (quitStakePoolEp p w) Default payload
 
-joinStakePoolFee
+delegationFee
     :: forall t w. (HasType (ApiT WalletId) w)
     => Context t
-    -> ApiT PoolId
     -> w
     -> IO (HTTP.Status, Either RequestException ApiFee)
-joinStakePoolFee ctx p w = do
-    request @ApiFee ctx (joinStakePoolFeeEp p w) Default Empty
+delegationFee ctx w = do
+    request @ApiFee ctx (delegationFeeEp w) Default Empty
 
 listAddresses
     :: Context t
@@ -1364,14 +1363,15 @@ joinStakePoolEp
     -> (Method, Text)
 joinStakePoolEp = stakePoolEp "PUT"
 
-joinStakePoolFeeEp
+delegationFeeEp
     :: forall w. (HasType (ApiT WalletId) w)
-    => ApiT PoolId
-    -> w
+    => w
     -> (Method, Text)
-joinStakePoolFeeEp pid w = (verb, path <> "/fee")
-    where
-       (verb, path) = stakePoolEp "GET" pid w
+delegationFeeEp w =
+    ( "GET"
+    , "v2/wallets/" <> w ^. walletId <> "/delegations/fees"
+    )
+
 
 quitStakePoolEp
     :: forall w. (HasType (ApiT WalletId) w)
diff --git a/lib/core-integration/src/Test/Integration/Framework/TestData.hs b/lib/core-integration/src/Test/Integration/Framework/TestData.hs
index b6fff524112..3b3409e5a92 100644
--- a/lib/core-integration/src/Test/Integration/Framework/TestData.hs
+++ b/lib/core-integration/src/Test/Integration/Framework/TestData.hs
@@ -32,10 +32,6 @@ module Test.Integration.Framework.TestData
     , russianWalletName
     , wildcardsWalletName
 
-    -- * Stake pool ids
-    , nonExistingStakePool1
-    , invalidPoolIds
-
     -- * Helpers
     , addressPoolGapMax
     , addressPoolGapMin
@@ -271,22 +267,6 @@ wildcardsWalletName = "`~`!@#$%^&*()_+-=<>,./?;':\"\"'{}[]\\|❤️ 💔 💌 
 \💓 💗 💖 💘 💝 💟 💜 💛 💚 💙0️⃣ 1️⃣ 2️⃣ 3️⃣ 4️⃣ 5️⃣ 6️⃣ 7️⃣ 8️⃣ 9️⃣ 🔟🇺🇸🇷🇺🇸 🇦🇫🇦🇲🇸"
 
 
---
--- Stake Pools
---
-
-nonExistingStakePool1 :: Text
-nonExistingStakePool1 = "008d686a02c6e625b5a59cc9e234f32e5d72987012f9c25c9a6b60ddade197d1"
-
-invalidPoolIds :: [(String, String)]
-invalidPoolIds =
-        [ ("64 chars non-hex", replicate 64 'ś')
-        , ("63 chars hex", replicate 63 '1')
-        , ("65 chars hex", replicate 65 '1')
-        , ("64 chars hex", replicate 64 '1')
-        , ("empty", "")
-        ]
-
 ---
 --- Helpers
 ---
diff --git a/lib/core/src/Cardano/Wallet/Api.hs b/lib/core/src/Cardano/Wallet/Api.hs
index feab779d93e..f13443fcf94 100644
--- a/lib/core/src/Cardano/Wallet/Api.hs
+++ b/lib/core/src/Cardano/Wallet/Api.hs
@@ -138,8 +138,8 @@ type CoreApi t =
 type StakePoolApi t =
     ListStakePools
     :<|> JoinStakePool t
-    :<|> JoinStakePoolFee
     :<|> QuitStakePool t
+    :<|> DelegationFee
 
 type CompatibilityApi n =
     DeleteByronWallet
@@ -284,12 +284,11 @@ type JoinStakePool t = "stake-pools"
     :> PutAcccepted '[JSON] (ApiTransaction t)
 
 
--- | https://input-output-hk.github.io/cardano-wallet/api/#operation/joinStakePool
-type JoinStakePoolFee = "stake-pools"
-    :> Capture "stakePoolId" (ApiT PoolId)
-    :> "wallets"
+-- | https://input-output-hk.github.io/cardano-wallet/api/#operation/delegationFee
+type DelegationFee = "wallets"
     :> Capture "walletId" (ApiT WalletId)
-    :> "fee"
+    :> "delegations"
+    :> "fees"
     :> Get '[JSON] ApiFee
 
 -- | https://input-output-hk.github.io/cardano-wallet/api/#operation/quitStakePool
diff --git a/lib/core/src/Cardano/Wallet/Api/Server.hs b/lib/core/src/Cardano/Wallet/Api/Server.hs
index 064d4a80685..26ecd92ef03 100644
--- a/lib/core/src/Cardano/Wallet/Api/Server.hs
+++ b/lib/core/src/Cardano/Wallet/Api/Server.hs
@@ -787,8 +787,8 @@ stakePools
 stakePools ctx spl =
     listPools spl
     :<|> joinStakePool ctx spl
-    :<|> joinStakePoolFee ctx spl
     :<|> quitStakePool ctx
+    :<|> delegationFee ctx
 
 listPools
     :: StakePoolLayer IO
@@ -838,7 +838,7 @@ joinStakePool ctx spl (ApiT pid) (ApiT wid) (ApiWalletPassphrase (ApiT pwd)) = d
   where
     liftE = throwE . ErrJoinStakePoolNoSuchWallet
 
-joinStakePoolFee
+delegationFee
     :: forall ctx s t n k.
         ( DelegationAddress n k
         , Buildable (ErrValidateSelection t)
@@ -848,11 +848,9 @@ joinStakePoolFee
         , ctx ~ ApiLayer s t k
         )
     => ctx
-    -> StakePoolLayer IO
-    -> ApiT PoolId
     -> ApiT WalletId
     -> Handler ApiFee
-joinStakePoolFee ctx _spl (ApiT _pid) (ApiT wid) = do
+delegationFee ctx (ApiT wid) = do
     liftHandler $ withWorkerCtx ctx wid liftE $ \wrk ->
          apiFee <$> W.selectCoinsForDelegation @_ @s @t @k wrk wid
   where
diff --git a/lib/jormungandr/test/integration/Test/Integration/Jormungandr/Scenario/API/StakePools.hs b/lib/jormungandr/test/integration/Test/Integration/Jormungandr/Scenario/API/StakePools.hs
index 719b58a9e62..6bc02067480 100644
--- a/lib/jormungandr/test/integration/Test/Integration/Jormungandr/Scenario/API/StakePools.hs
+++ b/lib/jormungandr/test/integration/Test/Integration/Jormungandr/Scenario/API/StakePools.hs
@@ -48,6 +48,8 @@ import Test.Integration.Framework.DSL
     , balanceTotal
     , blocks
     , delegation
+    , delegationFee
+    , delegationFeeEp
     , direction
     , emptyByronWallet
     , emptyWallet
@@ -71,8 +73,6 @@ import Test.Integration.Framework.DSL
     , getWalletEp
     , joinStakePool
     , joinStakePoolEp
-    , joinStakePoolFee
-    , joinStakePoolFeeEp
     , json
     , listStakePoolsEp
     , listTxEp
@@ -100,7 +100,6 @@ import Test.Integration.Framework.TestData
     , errMsg406
     , errMsg415
     , falseWalletIds
-    , invalidPoolIds
     , passphraseMaxLength
     , passphraseMinLength
     )
@@ -513,11 +512,17 @@ spec = do
         r <- joinStakePool ctx (p ^. #id) (w, "Secure Passprase")
         expectResponseCode HTTP.status404 r
 
+    -- NOTE
+    -- This is only true because:
+    --
+    -- 1/ We are in Jörmungandr scenario were fees can be known exactly
+    -- 2/ Fixture wallets are made of homogeneous UTxOs (all equal to the same
+    -- value) and therefore, the random selection has no influence.
     it "STAKE_POOLS_ESTIMATE_FEE_01 - fee matches eventual cost" $ \ctx -> do
         (_, p:_) <- eventually $
             unsafeRequest @[ApiStakePool] ctx listStakePoolsEp Empty
         w <- fixtureWallet ctx
-        fee <- getFromResponse amount <$> joinStakePoolFee ctx (p ^. #id) w
+        fee <- getFromResponse amount <$> delegationFee ctx w
         r <- joinStakePool ctx (p ^. #id) (w, fixturePassphrase)
         verify r
             [ expectFieldEqual amount fee
@@ -525,37 +530,30 @@ spec = do
 
     it "STAKE_POOLS_ESTIMATE_FEE_02 - \
         \empty wallet cannot estimate fee" $ \ctx -> do
-        (_, p:_) <- eventually $
-            unsafeRequest @[ApiStakePool] ctx listStakePoolsEp Empty
         w <- emptyWallet ctx
-        joinStakePoolFee ctx (p ^. #id) w >>= flip verify
+        let (fee, _) = ctx ^. feeEstimator $ DelegDescription 0 0 1
+        delegationFee ctx w >>= flip verify
             [ expectResponseCode HTTP.status403
-            , expectErrorMessage $ errMsg403DelegationFee stakeDelegationFee
+            , expectErrorMessage $ errMsg403DelegationFee fee
             ]
 
     it "STAKE_POOLS_ESTIMATE_FEE_03 - can't use byron wallets" $ \ctx -> do
-        (_, p:_) <- eventually $
-            unsafeRequest @[ApiStakePool] ctx listStakePoolsEp Empty
         w <- fixtureByronWallet ctx
-        let ep = joinStakePoolFeeEp (p ^. #id) w
+        let ep = delegationFeeEp w
         r <- request @(ApiTransaction 'Mainnet) ctx ep Default Empty
         verify r
             [ expectResponseCode HTTP.status404 -- should fail
             , expectErrorMessage $ errMsg404NoWallet (w ^. walletId)
             ]
 
-    describe "STAKE_POOLS_ESTIMATE_FEE_04 - invalid pool and wallet ids" $ do
-        forM_ invalidPoolIds $ \(pDesc, poolId) ->
-            forM_ falseWalletIds $ \(wDesc, walId) -> do
-            let path = poolId <> "/wallets/" <> walId
-            it ("pool:" ++ pDesc ++ ", wallet:" ++ wDesc) $ \ctx -> do
-                let endpoint = "v2/stake-pools/"
-                                <> T.pack path
-                                <> "/fee"
-                rg <- request @ApiFee ctx ("GET", endpoint)
-                    Default Empty
+    describe "STAKE_POOLS_ESTIMATE_FEE_04 - wallet ids" $ do
+        forM_ falseWalletIds $ \(wDesc, walId) -> do
+            let path = "wallets/" <> walId
+            it ("wallet:" ++ wDesc) $ \ctx -> do
+                let endpoint = "v2/" <> T.pack path <> "/delegations/fees"
+                rg <- request @ApiFee ctx ("GET", endpoint) Default Empty
                 expectResponseCode @IO HTTP.status404 rg
-                if pDesc == "64 chars hex" && wDesc == "40 chars hex"
+                if wDesc == "40 chars hex"
                 then expectErrorMessage (errMsg404NoWallet $ T.pack walId) rg
                 else expectErrorMessage errMsg404NoEndpoint rg
 
diff --git a/specifications/api/swagger.yaml b/specifications/api/swagger.yaml
index f85276ac667..08192a1fe70 100644
--- a/specifications/api/swagger.yaml
+++ b/specifications/api/swagger.yaml
@@ -1035,6 +1035,7 @@ x-responsesPostExternalTransaction: &responsesPostExternalTransaction
 
 x-responsesPostTransactionFee: &responsesPostTransactionFee
   <<: *responsesErr400
+  <<: *responsesErr403
   <<: *responsesErr404
   <<: *responsesErr405
   <<: *responsesErr406
@@ -1044,7 +1045,8 @@ x-responsesPostTransactionFee: &responsesPostTransactionFee
     schema:
       <<: *ApiFee
 
-x-responsesGetJoinStakePoolFee: &responsesGetJoinStakePoolFee
+x-responsesGetDelegationFee: &responsesGetDelegationFee
+  <<: *responsesErr403
   <<: *responsesErr404
   <<: *responsesErr405
   <<: *responsesErr406
@@ -1072,7 +1074,7 @@ x-responsesListStakePools: &responsesListStakePools
         type: array
         items: *ApiStakePool
 
-x-responsesJoinStakePool: &responsesJoinStakePool
+x-: &responsesJoinStakePool
   <<: *responsesErr400
   <<: *responsesErr403
   <<: *responsesErr404
@@ -1084,7 +1086,7 @@ x-responsesJoinStakePool: &responsesJoinStakePool
     schema: *ApiTransaction
 
 x-responsesQuitStakePool: &responsesQuitStakePool
-  <<: *responsesJoinStakePool
+  <<: *
 
 x-responsesGetNetworkInformation: &responsesGetNetworkInformation
   <<: *responsesErr405
@@ -1252,7 +1254,7 @@ paths:
     post:
       operationId: postTransactionFee
       tags: ["Transactions"]
-      summary: Estimate
+      summary: Estimate Fee
       description: |
         <p align="right">status: <strong>stable</strong></p>
 
@@ -1328,7 +1330,7 @@ paths:
         - *parametersWalletId
         - <<: *parametersBody
           schema: *parametersJoinStakePool
-      responses: *responsesJoinStakePool
+      responses: *
 
     delete:
       operationId: quitStakePool
@@ -1345,19 +1347,21 @@ paths:
           schema: *parametersQuitStakePool
       responses: *responsesQuitStakePool
 
-  /stake-pools/{stakePoolId}/wallets/{walletId}/fee:
+  /wallets/{walletId}/delegations/fees:
     get:
-      operationId: joinStakePoolFee
+      operationId: getDelegationFee
       tags: ["Stake Pools"]
-      summary: Estimate
+      summary: Estimate Fee
       description: |
         <p align="right">status: <strong>stable</strong></p>
 
-        Estimate fee for joining a stake pool.
+        Estimate fee for joining or leaving a stake pool. Note that it is an
+        estimation because a delegation induces a transaction for which coins
+        have to be selected randomly within the wallet. Because of this randomness,
+        fees can only be estimated.
       parameters:
-        - *parametersStakePoolId
         - *parametersWalletId
-      responses: *responsesGetJoinStakePoolFee
+      responses: *responsesGetDelegationFee
 
   /byron-wallets:
     get: