diff --git a/codex.nimble b/codex.nimble
index 29480888..e1200d71 100644
--- a/codex.nimble
+++ b/codex.nimble
@@ -20,7 +20,7 @@ requires "nimcrypto >= 0.4.1"
 requires "nitro >= 0.5.1 & < 0.6.0"
 requires "presto"
 requires "protobuf_serialization >= 0.2.0 & < 0.3.0"
-requires "questionable >= 0.10.6 & < 0.11.0"
+requires "questionable >= 0.10.12 & < 0.11.0"
 requires "secp256k1"
 requires "stew"
 requires "upraises >= 0.1.0 & < 0.2.0"
diff --git a/codex/sales/reservations.nim b/codex/sales/reservations.nim
index ec5d2777..19aff95d 100644
--- a/codex/sales/reservations.nim
+++ b/codex/sales/reservations.nim
@@ -181,7 +181,7 @@ proc getImpl(
   self: Reservations,
   key: Key): Future[?!seq[byte]] {.async.} =
 
-  if exists =? (await self.exists(key)) and not exists:
+  if not await self.exists(key):
     let err = newException(NotExistsError, "object with key " & $key & " does not exist")
     return failure(err)
 
@@ -226,7 +226,7 @@ proc delete(
 
   trace "deleting object", key
 
-  if exists =? (await self.exists(key)) and not exists:
+  if not await self.exists(key):
     return success()
 
   if err =? (await self.repo.metaDs.delete(key)).errorOption:
diff --git a/codex/sales/states/cancelled.nim b/codex/sales/states/cancelled.nim
index 54b8e553..3f0e2157 100644
--- a/codex/sales/states/cancelled.nim
+++ b/codex/sales/states/cancelled.nim
@@ -20,19 +20,15 @@ method run*(state: SaleCancelled, machine: Machine): Future[?State] {.async.} =
   without request =? data.request:
     raiseAssert "no sale request"
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
-  let slot = Slot(request: request, slotIndex: slotIndex)
-  debug "Collecting collateral and partial payout",  requestId = $data.requestId, slotIndex
+  let slot = Slot(request: request, slotIndex: data.slotIndex)
+  debug "Collecting collateral and partial payout",  requestId = $data.requestId, slotIndex = $data.slotIndex
   await market.freeSlot(slot.id)
 
   if onClear =? agent.context.onClear and
-      request =? data.request and
-      slotIndex =? data.slotIndex:
-    onClear(request, slotIndex)
+      request =? data.request:
+    onClear(request, data.slotIndex)
 
   if onCleanUp =? agent.onCleanUp:
     await onCleanUp()
 
-  warn "Sale cancelled due to timeout",  requestId = $data.requestId, slotIndex
+  warn "Sale cancelled due to timeout",  requestId = $data.requestId, slotIndex = $data.slotIndex
diff --git a/codex/sales/states/downloading.nim b/codex/sales/states/downloading.nim
index 50f4f8e6..6298657c 100644
--- a/codex/sales/states/downloading.nim
+++ b/codex/sales/states/downloading.nim
@@ -42,15 +42,12 @@ method run*(state: SaleDownloading, machine: Machine): Future[?State] {.async.}
   without request =? data.request:
     raiseAssert "no sale request"
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
   without reservation =? data.reservation:
     raiseAssert("no reservation")
 
   logScope:
     requestId = request.id
-    slotIndex
+    slotIndex = data.slotIndex
     reservationId = reservation.id
     availabilityId = reservation.availabilityId
 
@@ -72,7 +69,7 @@ method run*(state: SaleDownloading, machine: Machine): Future[?State] {.async.}
 
   trace "Starting download"
   if err =? (await onStore(request,
-                           slotIndex,
+                           data.slotIndex,
                            onBatch)).errorOption:
     return some State(SaleErrored(error: err))
 
diff --git a/codex/sales/states/errored.nim b/codex/sales/states/errored.nim
index a6d5bfb4..c934be4b 100644
--- a/codex/sales/states/errored.nim
+++ b/codex/sales/states/errored.nim
@@ -25,9 +25,8 @@ method run*(state: SaleErrored, machine: Machine): Future[?State] {.async.} =
   error "Sale error", error=state.error.msgDetail, requestId = data.requestId, slotIndex = data.slotIndex
 
   if onClear =? context.onClear and
-      request =? data.request and
-      slotIndex =? data.slotIndex:
-    onClear(request, slotIndex)
+      request =? data.request:
+    onClear(request, data.slotIndex)
 
   if onCleanUp =? agent.onCleanUp:
     await onCleanUp()
diff --git a/codex/sales/states/failed.nim b/codex/sales/states/failed.nim
index 461beb13..cd954be4 100644
--- a/codex/sales/states/failed.nim
+++ b/codex/sales/states/failed.nim
@@ -20,11 +20,8 @@ method run*(state: SaleFailed, machine: Machine): Future[?State] {.async.} =
   without request =? data.request:
     raiseAssert "no sale request"
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
-  let slot = Slot(request: request, slotIndex: slotIndex)
-  debug "Removing slot from mySlots",  requestId = $data.requestId, slotIndex
+  let slot = Slot(request: request, slotIndex: data.slotIndex)
+  debug "Removing slot from mySlots",  requestId = $data.requestId, slotIndex = $data.slotIndex
   await market.freeSlot(slot.id)
 
   let error = newException(SaleFailedError, "Sale failed")
diff --git a/codex/sales/states/filled.nim b/codex/sales/states/filled.nim
index 5139a8c3..a6803c25 100644
--- a/codex/sales/states/filled.nim
+++ b/codex/sales/states/filled.nim
@@ -29,19 +29,17 @@ method run*(state: SaleFilled, machine: Machine): Future[?State] {.async.} =
   let agent = SalesAgent(machine)
   let data = agent.data
   let context = agent.context
+
   let market = context.market
-
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
-  let host = await market.getHost(data.requestId, slotIndex)
+  let host = await market.getHost(data.requestId, data.slotIndex)
   let me = await market.getSigner()
-  if host == me.some:
-    info "Slot succesfully filled", requestId = $data.requestId, slotIndex
 
-    if request =? data.request and slotIndex =? data.slotIndex:
+  if host == me.some:
+    info "Slot succesfully filled", requestId = $data.requestId, slotIndex = $data.slotIndex
+
+    if request =? data.request:
       if onFilled =? agent.onFilled:
-        onFilled(request, slotIndex)
+        onFilled(request, data.slotIndex)
 
     when codex_enable_proof_failures:
       if context.simulateProofFailures > 0:
diff --git a/codex/sales/states/filling.nim b/codex/sales/states/filling.nim
index 5cf6a06d..b1e8471c 100644
--- a/codex/sales/states/filling.nim
+++ b/codex/sales/states/filling.nim
@@ -32,8 +32,5 @@ method run(state: SaleFilling, machine: Machine): Future[?State] {.async.} =
   without (collateral =? data.request.?ask.?collateral):
     raiseAssert "Request not set"
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
-  debug "Filling slot", requestId = $data.requestId, slotIndex
-  await market.fillSlot(data.requestId, slotIndex, state.proof, collateral)
+  debug "Filling slot", requestId = $data.requestId, slotIndex = $data.slotIndex
+  await market.fillSlot(data.requestId, data.slotIndex, state.proof, collateral)
diff --git a/codex/sales/states/finished.nim b/codex/sales/states/finished.nim
index 5b1c6003..539cde62 100644
--- a/codex/sales/states/finished.nim
+++ b/codex/sales/states/finished.nim
@@ -27,10 +27,7 @@ method run*(state: SaleFinished, machine: Machine): Future[?State] {.async.} =
   without request =? data.request:
     raiseAssert "no sale request"
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
-  info "Slot finished and paid out", requestId = $data.requestId, slotIndex
+  info "Slot finished and paid out", requestId = $data.requestId, slotIndex = $data.slotIndex
 
   if onCleanUp =? agent.onCleanUp:
     await onCleanUp()
diff --git a/codex/sales/states/initialproving.nim b/codex/sales/states/initialproving.nim
index 7f5da6b6..0cbbb7b7 100644
--- a/codex/sales/states/initialproving.nim
+++ b/codex/sales/states/initialproving.nim
@@ -30,11 +30,8 @@ method run*(state: SaleInitialProving, machine: Machine): Future[?State] {.async
   without onProve =? context.onProve:
     raiseAssert "onProve callback not set"
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
   debug "Generating initial proof", requestId = $data.requestId
-  let proof = await onProve(Slot(request: request, slotIndex: slotIndex))
+  let proof = await onProve(Slot(request: request, slotIndex: data.slotIndex))
   debug "Finished proof calculation", requestId = $data.requestId
 
   return some State(SaleFilling(proof: proof))
diff --git a/codex/sales/states/payout.nim b/codex/sales/states/payout.nim
index 68cdfbc9..a70f7eac 100644
--- a/codex/sales/states/payout.nim
+++ b/codex/sales/states/payout.nim
@@ -28,11 +28,8 @@ method run(state: SalePayout, machine: Machine): Future[?State] {.async.} =
   without request =? data.request:
     raiseAssert "no sale request"
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
-  let slot = Slot(request: request, slotIndex: slotIndex)
-  debug "Collecting finished slot's reward",  requestId = $data.requestId, slotIndex
+  let slot = Slot(request: request, slotIndex: data.slotIndex)
+  debug "Collecting finished slot's reward",  requestId = $data.requestId, slotIndex = $data.slotIndex
   await market.freeSlot(slot.id)
 
   return some State(SaleFinished())
diff --git a/codex/sales/states/proving.nim b/codex/sales/states/proving.nim
index 5586c9ca..22cd50b4 100644
--- a/codex/sales/states/proving.nim
+++ b/codex/sales/states/proving.nim
@@ -112,18 +112,15 @@ method run*(state: SaleProving, machine: Machine): Future[?State] {.async.} =
   without onProve =? context.onProve:
     raiseAssert "onProve callback not set"
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
   without market =? context.market:
     raiseAssert("market not set")
 
   without clock =? context.clock:
     raiseAssert("clock not set")
 
-  debug "Start proving", requestId = $data.requestId, slotIndex
+  debug "Start proving", requestId = $data.requestId, slotIndex = $data.slotIndex
   try:
-    let loop = state.proveLoop(market, clock, request, slotIndex, onProve)
+    let loop = state.proveLoop(market, clock, request, data.slotIndex, onProve)
     state.loop = loop
     await loop
   except CancelledError:
@@ -133,7 +130,7 @@ method run*(state: SaleProving, machine: Machine): Future[?State] {.async.} =
     return some State(SaleErrored(error: e))
   finally:
     # Cleanup of the proving loop
-    debug "Stopping proving.", requestId = $data.requestId, slotIndex
+    debug "Stopping proving.", requestId = $data.requestId, slotIndex = $data.slotIndex
 
     if not state.loop.isNil:
         if not state.loop.finished:
diff --git a/codex/sales/states/unknown.nim b/codex/sales/states/unknown.nim
index 0cd5684d..3672ed96 100644
--- a/codex/sales/states/unknown.nim
+++ b/codex/sales/states/unknown.nim
@@ -32,14 +32,8 @@ method run*(state: SaleUnknown, machine: Machine): Future[?State] {.async.} =
   await agent.retrieveRequest()
   await agent.subscribe()
 
-  without slotIndex =? data.slotIndex:
-    raiseAssert("no slot index assigned")
-
-  let slotId = slotId(data.requestId, slotIndex)
-
-  without slotState =? await market.slotState(slotId):
-    let error = newException(SaleUnknownError, "cannot retrieve slot state")
-    return some State(SaleErrored(error: error))
+  let slotId = slotId(data.requestId, data.slotIndex)
+  let slotState = await market.slotState(slotId)
 
   case slotState
   of SlotState.Free:
diff --git a/tests/codex/sales/testreservations.nim b/tests/codex/sales/testreservations.nim
index 4a7d94d7..3bfee998 100644
--- a/tests/codex/sales/testreservations.nim
+++ b/tests/codex/sales/testreservations.nim
@@ -83,8 +83,7 @@ asyncchecksuite "Reservations module":
   test "reserved availability exists":
     let availability = createAvailability()
 
-    without exists =? await reservations.exists(availability.key.get):
-      fail()
+    let exists = await reservations.exists(availability.key.get)
 
     check exists
 
diff --git a/tests/integration/nodes.nim b/tests/integration/nodes.nim
index d85e9a6f..777de80b 100644
--- a/tests/integration/nodes.nim
+++ b/tests/integration/nodes.nim
@@ -88,5 +88,4 @@ proc restart*(node: NodeProcess) =
   node.waitUntilStarted()
 
 proc removeDataDir*(node: NodeProcess) =
-  if dataDir =? node.dataDir:
-    removeDir(dataDir)
+  removeDir(node.dataDir)
diff --git a/tests/integration/testIntegration.nim b/tests/integration/testIntegration.nim
index 5bdc0d1f..9b311a05 100644
--- a/tests/integration/testIntegration.nim
+++ b/tests/integration/testIntegration.nim
@@ -22,7 +22,9 @@ import ./twonodes
 twonodessuite "Integration tests", debug1 = false, debug2 = false:
 
   proc purchaseStateIs(client: CodexClient, id: PurchaseId, state: string): bool =
-    client.getPurchase(id).option.?state == some state
+    without purchase =? client.getPurchase(id):
+      return false
+    return purchase.state == state
 
   setup:
     # Our Hardhat configuration does use automine, which means that time tracked by `provider.currentTime()` is not
diff --git a/vendor/questionable b/vendor/questionable
index e56cf86c..2dd6b6b2 160000
--- a/vendor/questionable
+++ b/vendor/questionable
@@ -1 +1 @@
-Subproject commit e56cf86c4a089c78a1b7c3005f13343bfbbe3b48
+Subproject commit 2dd6b6b220f9f14a1231f6cafdf24f012bcc8414