diff --git a/codex/node.nim b/codex/node.nim
index 84716471..4d489c83 100644
--- a/codex/node.nim
+++ b/codex/node.nim
@@ -313,11 +313,13 @@ proc start*(node: CodexNodeRef) {.async.} =
 
   if contracts =? node.contracts:
     # TODO: remove Sales callbacks, pass BlockStore and StorageProofs instead
-    contracts.sales.onStore = proc(cid: string, _: Availability) {.async.} =
+    contracts.sales.onStore = proc(request: StorageRequest,
+                                   slot: UInt256,
+                                   availability: Availability) {.async.} =
       ## store data in local storage
       ##
 
-      without cid =? Cid.init(cid):
+      without cid =? Cid.init(request.content.cid):
         trace "Unable to parse Cid", cid
         raise newException(CodexError, "Unable to parse Cid")
 
diff --git a/codex/sales.nim b/codex/sales.nim
index 12b0f051..1fc0f8ce 100644
--- a/codex/sales.nim
+++ b/codex/sales.nim
@@ -54,7 +54,9 @@ type
     running: ?Future[void]
     waiting: ?Future[void]
     finished: bool
-  OnStore = proc(cid: string, availability: Availability): Future[void] {.gcsafe, upraises: [].}
+  OnStore = proc(request: StorageRequest,
+                 slot: UInt256,
+                 availability: Availability): Future[void] {.gcsafe, upraises: [].}
   OnProve = proc(cid: string): Future[seq[byte]] {.gcsafe, upraises: [].}
   OnClear = proc(availability: Availability, request: StorageRequest) {.gcsafe, upraises: [].}
   OnSale = proc(availability: Availability,
@@ -184,7 +186,7 @@ proc start(agent: SalesAgent) {.async.} =
 
     agent.waiting = some agent.waitForExpiry()
 
-    await onStore(request.content.cid, availability)
+    await onStore(request, slotIndex, availability)
     let proof = await onProve(request.content.cid)
     await market.fillSlot(request.id, slotIndex, proof)
   except CancelledError:
diff --git a/tests/codex/testsales.nim b/tests/codex/testsales.nim
index 589a054e..b164d3d2 100644
--- a/tests/codex/testsales.nim
+++ b/tests/codex/testsales.nim
@@ -33,7 +33,9 @@ suite "Sales":
     market = MockMarket.new()
     clock = MockClock.new()
     sales = Sales.new(market, clock)
-    sales.onStore = proc(cid: string, availability: Availability) {.async.} =
+    sales.onStore = proc(request: StorageRequest,
+                         slot: UInt256,
+                         availability: Availability) {.async.} =
       discard
     sales.onProve = proc(cid: string): Future[seq[byte]] {.async.} =
       return proof
@@ -85,18 +87,26 @@ suite "Sales":
     check sales.available == @[availability]
 
   test "retrieves and stores data locally":
-    var storingCid: string
+    var storingRequest: StorageRequest
+    var storingSlot: UInt256
     var storingAvailability: Availability
-    sales.onStore = proc(cid: string, availability: Availability) {.async.} =
-      storingCid = cid
+    sales.onStore = proc(request: StorageRequest,
+                         slot: UInt256,
+                         availability: Availability) {.async.} =
+      storingRequest = request
+      storingSlot = slot
       storingAvailability = availability
     sales.add(availability)
-    discard await market.requestStorage(request)
-    check storingCid == request.content.cid
+    let requested = await market.requestStorage(request)
+    check storingRequest == requested
+    check storingSlot < request.ask.slots.u256
+    check storingAvailability == availability
 
   test "makes storage available again when data retrieval fails":
     let error = newException(IOError, "data retrieval failed")
-    sales.onStore = proc(cid: string, availability: Availability) {.async.} =
+    sales.onStore = proc(request: StorageRequest,
+                         slot: UInt256,
+                         availability: Availability) {.async.} =
       raise error
     sales.add(availability)
     discard await market.requestStorage(request)
@@ -149,7 +159,9 @@ suite "Sales":
 
   test "makes storage available again when other host fills the slot":
     let otherHost = Address.example
-    sales.onStore = proc(cid: string, availability: Availability) {.async.} =
+    sales.onStore = proc(request: StorageRequest,
+                         slot: UInt256,
+                         availability: Availability) {.async.} =
       await sleepAsync(1.hours)
     sales.add(availability)
     discard await market.requestStorage(request)
@@ -158,7 +170,9 @@ suite "Sales":
     check sales.available == @[availability]
 
   test "makes storage available again when request expires":
-    sales.onStore = proc(cid: string, availability: Availability) {.async.} =
+    sales.onStore = proc(request: StorageRequest,
+                         slot: UInt256,
+                         availability: Availability) {.async.} =
       await sleepAsync(1.hours)
     sales.add(availability)
     discard await market.requestStorage(request)