diff --git a/codex/blockexchange/engine/engine.nim b/codex/blockexchange/engine/engine.nim
index 97e7cb99..60a7a689 100644
--- a/codex/blockexchange/engine/engine.nim
+++ b/codex/blockexchange/engine/engine.nim
@@ -129,7 +129,6 @@ proc sendWantHave(
   for p in peers:
     if p notin excluded:
       if address notin p.peerHave:
-        trace " wantHave > ", peer = p.id
         await b.network.request.sendWantList(
           p.id,
           @[address],
@@ -145,11 +144,18 @@ proc sendWantBlock(
     @[address],
     wantType = WantType.WantBlock) # we want this remote to send us a block
 
-proc monitorBlockHandle(b: BlockExcEngine, handle: Future[Block], address: BlockAddress, peerId: PeerId) {.async.} =
+proc monitorBlockHandle(
+  b: BlockExcEngine,
+  handle: Future[Block],
+  address: BlockAddress,
+  peerId: PeerId) {.async.} =
+
   try:
     trace "Monitoring block handle", address, peerId
     discard await handle
     trace "Block handle success", address, peerId
+  except CancelledError as exc:
+    trace "Block handle cancelled", address, peerId
   except CatchableError as exc:
     trace "Error block handle, disconnecting peer", address, exc = exc.msg, peerId
 
@@ -167,38 +173,38 @@ proc monitorBlockHandle(b: BlockExcEngine, handle: Future[Block], address: Block
 proc requestBlock*(
   b: BlockExcEngine,
   address: BlockAddress,
-  timeout = DefaultBlockTimeout): Future[Block] {.async.} =
+  timeout = DefaultBlockTimeout): Future[?!Block] {.async.} =
   let blockFuture = b.pendingBlocks.getWantHandle(address, timeout)
 
   if b.pendingBlocks.isInFlight(address):
-    return await blockFuture
+    success await blockFuture
+  else:
+    let peers = b.peers.selectCheapest(address)
+    if peers.len == 0:
+      b.discovery.queueFindBlocksReq(@[address.cidOrTreeCid])
 
-  let peers = b.peers.selectCheapest(address)
-  if peers.len == 0:
-    b.discovery.queueFindBlocksReq(@[address.cidOrTreeCid])
+    let maybePeer =
+      if peers.len > 0:
+        peers[hash(address) mod peers.len].some
+      elif b.peers.len > 0:
+        toSeq(b.peers)[hash(address) mod b.peers.len].some
+      else:
+        BlockExcPeerCtx.none
 
-  let maybePeer =
-    if peers.len > 0:
-      peers[hash(address) mod peers.len].some
-    elif b.peers.len > 0:
-      toSeq(b.peers)[hash(address) mod b.peers.len].some
-    else:
-      BlockExcPeerCtx.none
+    if peer =? maybePeer:
+      asyncSpawn b.monitorBlockHandle(blockFuture, address, peer.id)
+      b.pendingBlocks.setInFlight(address)
+      await b.sendWantBlock(address, peer)
+      codex_block_exchange_want_block_lists_sent.inc()
+      await b.sendWantHave(address, @[peer], toSeq(b.peers))
+      codex_block_exchange_want_have_lists_sent.inc()
 
-  if peer =? maybePeer:
-    asyncSpawn b.monitorBlockHandle(blockFuture, address, peer.id)
-    b.pendingBlocks.setInFlight(address)
-    await b.sendWantBlock(address, peer)
-    codex_block_exchange_want_block_lists_sent.inc()
-    await b.sendWantHave(address, @[peer], toSeq(b.peers))
-    codex_block_exchange_want_have_lists_sent.inc()
-
-  return await blockFuture
+    success await blockFuture
 
 proc requestBlock*(
   b: BlockExcEngine,
   cid: Cid,
-  timeout = DefaultBlockTimeout): Future[Block] =
+  timeout = DefaultBlockTimeout): Future[?!Block] =
   b.requestBlock(BlockAddress.init(cid))
 
 proc blockPresenceHandler*(
@@ -298,7 +304,10 @@ proc resolveBlocks*(b: BlockExcEngine, blocksDelivery: seq[BlockDelivery]) {.asy
   b.discovery.queueProvideBlocksReq(cids.toSeq)
 
 proc resolveBlocks*(b: BlockExcEngine, blocks: seq[Block]) {.async.} =
-  await b.resolveBlocks(blocks.mapIt(BlockDelivery(blk: it, address: BlockAddress(leaf: false, cid: it.cid))))
+  await b.resolveBlocks(
+    blocks.mapIt(
+      BlockDelivery(blk: it, address: BlockAddress(leaf: false, cid: it.cid)
+  )))
 
 proc payForBlocks(engine: BlockExcEngine,
                   peer: BlockExcPeerCtx,
@@ -315,8 +324,7 @@ proc payForBlocks(engine: BlockExcEngine,
 
 proc validateBlockDelivery(
   b: BlockExcEngine,
-  bd: BlockDelivery
-): ?!void =
+  bd: BlockDelivery): ?!void =
   if bd.address notin b.pendingBlocks:
     return failure("Received block is not currently a pending block")
 
diff --git a/codex/blockexchange/engine/pendingblocks.nim b/codex/blockexchange/engine/pendingblocks.nim
index 2d517dfc..55a9da4c 100644
--- a/codex/blockexchange/engine/pendingblocks.nim
+++ b/codex/blockexchange/engine/pendingblocks.nim
@@ -44,11 +44,10 @@ proc updatePendingBlockGauge(p: PendingBlocksManager) =
   codex_block_exchange_pending_block_requests.set(p.blocks.len.int64)
 
 proc getWantHandle*(
-    p: PendingBlocksManager,
-    address: BlockAddress,
-    timeout = DefaultBlockTimeout,
-    inFlight = false
-): Future[Block] {.async.} =
+  p: PendingBlocksManager,
+  address: BlockAddress,
+  timeout = DefaultBlockTimeout,
+  inFlight = false): Future[Block] {.async.} =
   ## Add an event for a block
   ##
 
@@ -75,17 +74,15 @@ proc getWantHandle*(
     p.updatePendingBlockGauge()
 
 proc getWantHandle*(
-    p: PendingBlocksManager,
-    cid: Cid,
-    timeout = DefaultBlockTimeout,
-    inFlight = false
-): Future[Block] =
+  p: PendingBlocksManager,
+  cid: Cid,
+  timeout = DefaultBlockTimeout,
+  inFlight = false): Future[Block] =
   p.getWantHandle(BlockAddress.init(cid), timeout, inFlight)
 
 proc resolve*(
   p: PendingBlocksManager,
-  blocksDelivery: seq[BlockDelivery]
-  ) {.gcsafe, raises: [].} =
+  blocksDelivery: seq[BlockDelivery]) {.gcsafe, raises: [].} =
   ## Resolve pending blocks
   ##
 
@@ -108,16 +105,23 @@ proc resolve*(
     do:
       warn "Attempting to resolve block that's not currently a pending block", address = bd.address
 
-proc setInFlight*(p: PendingBlocksManager,
-                  address: BlockAddress,
-                  inFlight = true) =
+proc setInFlight*(
+  p: PendingBlocksManager,
+  address: BlockAddress,
+  inFlight = true) =
+  ## Set inflight status for a block
+  ##
+
   p.blocks.withValue(address, pending):
     pending[].inFlight = inFlight
     trace "Setting inflight", address, inFlight = pending[].inFlight
 
-proc isInFlight*(p: PendingBlocksManager,
-                 address: BlockAddress,
-                ): bool =
+proc isInFlight*(
+  p: PendingBlocksManager,
+  address: BlockAddress): bool =
+  ## Check if a block is in flight
+  ##
+
   p.blocks.withValue(address, pending):
     result = pending[].inFlight
     trace "Getting inflight", address, inFlight = result
@@ -145,7 +149,6 @@ iterator wantListCids*(p: PendingBlocksManager): Cid =
       yieldedCids.incl(cid)
       yield cid
 
-
 iterator wantHandles*(p: PendingBlocksManager): Future[Block] =
   for v in p.blocks.values:
     yield v.handle
diff --git a/codex/erasure/backends/leopard.nim b/codex/erasure/backends/leopard.nim
index 2051fc97..992e34da 100644
--- a/codex/erasure/backends/leopard.nim
+++ b/codex/erasure/backends/leopard.nim
@@ -22,10 +22,9 @@ type
     decoder*: Option[LeoDecoder]
 
 method encode*(
-    self: LeoEncoderBackend,
-    data,
-    parity: var openArray[seq[byte]]
-): Result[void, cstring] =
+  self: LeoEncoderBackend,
+  data,
+  parity: var openArray[seq[byte]]): Result[void, cstring] =
   ## Encode data using Leopard backend
 
   if parity.len == 0:
@@ -43,11 +42,10 @@ method encode*(
   encoder.encode(data, parity)
 
 method decode*(
-    self: LeoDecoderBackend,
-    data,
-    parity,
-    recovered: var openArray[seq[byte]]
-): Result[void, cstring] =
+  self: LeoDecoderBackend,
+  data,
+  parity,
+  recovered: var openArray[seq[byte]]): Result[void, cstring] =
   ## Decode data using given Leopard backend
 
   var decoder =
@@ -71,26 +69,24 @@ method release*(self: LeoDecoderBackend) =
     self.decoder.get().free()
 
 proc new*(
-    T: type LeoEncoderBackend,
-    blockSize,
-    buffers,
-    parity: int
-): LeoEncoderBackend =
+  T: type LeoEncoderBackend,
+  blockSize,
+  buffers,
+  parity: int): LeoEncoderBackend =
   ## Create an instance of an Leopard Encoder backend
-  ## 
+  ##
   LeoEncoderBackend(
     blockSize: blockSize,
     buffers: buffers,
     parity: parity)
 
 proc new*(
-    T: type LeoDecoderBackend,
-    blockSize,
-    buffers,
-    parity: int
-): LeoDecoderBackend =
+  T: type LeoDecoderBackend,
+  blockSize,
+  buffers,
+  parity: int): LeoDecoderBackend =
   ## Create an instance of an Leopard Decoder backend
-  ## 
+  ##
   LeoDecoderBackend(
     blockSize: blockSize,
     buffers: buffers,
diff --git a/codex/erasure/erasure.nim b/codex/erasure/erasure.nim
index 92b227aa..b03cfedd 100644
--- a/codex/erasure/erasure.nim
+++ b/codex/erasure/erasure.nim
@@ -241,7 +241,7 @@ proc init*(
 
   let
     rounded = roundUp(manifest.blocksCount, ecK)
-    steps = divUp(manifest.blocksCount, ecK)
+    steps = divUp(rounded, ecK)
     blocksCount = rounded + (steps * ecM)
 
   success EncodingParams(
diff --git a/codex/logutils.nim b/codex/logutils.nim
index 1c002b70..6abc21a5 100644
--- a/codex/logutils.nim
+++ b/codex/logutils.nim
@@ -239,3 +239,5 @@ formatIt(LogFormat.textLines, Cid): shortLog($it)
 formatIt(LogFormat.json, Cid): $it
 formatIt(UInt256): $it
 formatIt(MultiAddress): $it
+formatIt(LogFormat.textLines, array[32, byte]): it.short0xHexLog
+formatIt(LogFormat.json, array[32, byte]): it.to0xHex
diff --git a/codex/node.nim b/codex/node.nim
index ea66b55a..b8466943 100644
--- a/codex/node.nim
+++ b/codex/node.nim
@@ -556,6 +556,8 @@ proc onStore(
     trace "Unable to build slot", err = err.msg
     return failure(err)
 
+  trace "Slot successfully retrieved and reconstructed"
+
   if cid =? slotRoot.toSlotCid() and cid != manifest.slotRoots[slotIdx.int]:
     trace "Slot root mismatch", manifest = manifest.slotRoots[slotIdx.int], recovered = slotRoot.toSlotCid()
     return failure(newException(CodexError, "Slot root mismatch"))
@@ -593,25 +595,32 @@ proc onProve(
       error "Unable to fetch manifest for cid", err = err.msg
       return failure(err)
 
-    without builder =? Poseidon2Builder.new(self.networkStore.localStore, manifest), err:
-      error "Unable to create slots builder", err = err.msg
-      return failure(err)
+    when defined(verify_circuit):
+      without (inputs, proof) =? await prover.prove(slotIdx, manifest, challenge), err:
+        error "Unable to generate proof", err = err.msg
+        return failure(err)
 
-    without sampler =? DataSampler.new(slotIdx, self.networkStore.localStore, builder), err:
-      error "Unable to create data sampler", err = err.msg
-      return failure(err)
+      without checked =? await prover.verify(proof, inputs), err:
+        error "Unable to verify proof", err = err.msg
+        return failure(err)
 
-    without proofInput =? await sampler.getProofInput(challenge, nSamples = 3), err:
-      error "Unable to get proof input for slot", err = err.msg
-      return failure(err)
+      if not checked:
+        error "Proof verification failed"
+        return failure("Proof verification failed")
 
-  # Todo: send proofInput to circuit. Get proof. (Profit, repeat.)
+      trace "Proof verified successfully"
+    else:
+      without (_, proof) =? await prover.prove(slotIdx, manifest, challenge), err:
+        error "Unable to generate proof", err = err.msg
+        return failure(err)
 
-  # For now: dummy proof that is not all zero's, so that it is accepted by the
-  # dummy verifier:
-  var proof = Groth16Proof.default
-  proof.a.x = 42.u256
-  success(proof)
+    let groth16Proof = proof.toGroth16Proof()
+    trace "Proof generated successfully", groth16Proof
+
+    success groth16Proof
+  else:
+    warn "Prover not enabled"
+    failure "Prover not enabled"
 
 proc onExpiryUpdate(
   self: CodexNodeRef,
diff --git a/codex/sales/reservations.nim b/codex/sales/reservations.nim
index 6c68853e..997a085f 100644
--- a/codex/sales/reservations.nim
+++ b/codex/sales/reservations.nim
@@ -325,8 +325,9 @@ proc createReservation*(
     return failure(error)
 
   if availability.size < slotSize:
-    let error = newException(BytesOutOfBoundsError, "trying to reserve an " &
-      "amount of bytes that is greater than the total size of the Availability")
+    let error = newException(
+      BytesOutOfBoundsError,
+      "trying to reserve an amount of bytes that is greater than the total size of the Availability")
     return failure(error)
 
   if createResErr =? (await self.update(reservation)).errorOption:
@@ -427,9 +428,9 @@ proc release*(
     return failure(error)
 
   if reservation.size < bytes.u256:
-    let error = newException(BytesOutOfBoundsError,
-      "trying to release an amount of bytes that is greater than the total " &
-      "size of the Reservation")
+    let error = newException(
+      BytesOutOfBoundsError,
+      "trying to release an amount of bytes that is greater than the total size of the Reservation")
     return failure(error)
 
   if releaseErr =? (await self.repo.release(bytes)).errorOption:
@@ -540,7 +541,7 @@ proc findAvailability*(
 
         return some availability
 
-      trace "availiability did not match",
+      trace "availability did not match",
         size, availsize = availability.size,
         duration, availDuration = availability.duration,
         minPrice, availMinPrice = availability.minPrice,
diff --git a/codex/sales/states/initialproving.nim b/codex/sales/states/initialproving.nim
index 8f3a7287..4a5b8515 100644
--- a/codex/sales/states/initialproving.nim
+++ b/codex/sales/states/initialproving.nim
@@ -1,4 +1,5 @@
 import pkg/questionable/results
+import ../../clock
 import ../../logutils
 import ../statemachine
 import ../salesagent
@@ -22,9 +23,24 @@ method onCancelled*(state: SaleInitialProving, request: StorageRequest): ?State
 method onFailed*(state: SaleInitialProving, request: StorageRequest): ?State =
   return some State(SaleFailed())
 
+proc waitUntilNextPeriod(clock: Clock, periodicity: Periodicity) {.async.} =
+  trace "Waiting until next period"
+  let period = periodicity.periodOf(clock.now().u256)
+  let periodEnd = periodicity.periodEnd(period).truncate(int64)
+  await clock.waitUntil(periodEnd + 1)
+
+proc waitForStableChallenge(market: Market, clock: Clock, slotId: SlotId) {.async.} =
+  let periodicity = await market.periodicity()
+  let downtime = await market.proofDowntime()
+  await clock.waitUntilNextPeriod(periodicity)
+  while (await market.getPointer(slotId)) > (256 - downtime):
+    await clock.waitUntilNextPeriod(periodicity)
+
 method run*(state: SaleInitialProving, machine: Machine): Future[?State] {.async.} =
   let data = SalesAgent(machine).data
   let context = SalesAgent(machine).context
+  let market = context.market
+  let clock = context.clock
 
   without request =? data.request:
     raiseAssert "no sale request"
@@ -32,10 +48,12 @@ method run*(state: SaleInitialProving, machine: Machine): Future[?State] {.async
   without onProve =? context.onProve:
     raiseAssert "onProve callback not set"
 
+  debug "Waiting for a proof challenge that is valid for the entire period"
+  let slot = Slot(request: request, slotIndex: data.slotIndex)
+  await waitForStableChallenge(market, clock, slot.id)
+
   debug "Generating initial proof", requestId = data.requestId
-  let
-    slot = Slot(request: request, slotIndex: data.slotIndex)
-    challenge = await context.market.getChallenge(slot.id)
+  let challenge = await context.market.getChallenge(slot.id)
   without proof =? (await onProve(slot, challenge)), err:
     error "Failed to generate initial proof", error = err.msg
     return some State(SaleErrored(error: err))
diff --git a/codex/stores/blockstore.nim b/codex/stores/blockstore.nim
index d97d6948..4921bebb 100644
--- a/codex/stores/blockstore.nim
+++ b/codex/stores/blockstore.nim
@@ -61,10 +61,9 @@ method getBlockAndProof*(self: BlockStore, treeCid: Cid, index: Natural): Future
   raiseAssert("getBlockAndProof not implemented!")
 
 method putBlock*(
-    self: BlockStore,
-    blk: Block,
-    ttl = Duration.none
-): Future[?!void] {.base.} =
+  self: BlockStore,
+  blk: Block,
+  ttl = Duration.none): Future[?!void] {.base.} =
   ## Put a block to the blockstore
   ##
 
@@ -75,8 +74,7 @@ method putCidAndProof*(
   treeCid: Cid,
   index: Natural,
   blockCid: Cid,
-  proof: CodexProof
-): Future[?!void] {.base.} =
+  proof: CodexProof): Future[?!void] {.base.} =
   ## Put a block proof to the blockstore
   ##
 
@@ -92,10 +90,9 @@ method getCidAndProof*(
   raiseAssert("getCidAndProof not implemented!")
 
 method ensureExpiry*(
-    self: BlockStore,
-    cid: Cid,
-    expiry: SecondsSince1970
-): Future[?!void] {.base.} =
+  self: BlockStore,
+  cid: Cid,
+  expiry: SecondsSince1970): Future[?!void] {.base.} =
   ## Ensure that block's assosicated expiry is at least given timestamp
   ## If the current expiry is lower then it is updated to the given one, otherwise it is left intact
   ##
@@ -103,11 +100,10 @@ method ensureExpiry*(
   raiseAssert("Not implemented!")
 
 method ensureExpiry*(
-    self: BlockStore,
-    treeCid: Cid,
-    index: Natural,
-    expiry: SecondsSince1970
-): Future[?!void] {.base.} =
+  self: BlockStore,
+  treeCid: Cid,
+  index: Natural,
+  expiry: SecondsSince1970): Future[?!void] {.base.} =
   ## Ensure that block's associated expiry is at least given timestamp
   ## If the current expiry is lower then it is updated to the given one, otherwise it is left intact
   ##
diff --git a/codex/stores/networkstore.nim b/codex/stores/networkstore.nim
index 82a1428d..39835e23 100644
--- a/codex/stores/networkstore.nim
+++ b/codex/stores/networkstore.nim
@@ -8,8 +8,7 @@
 ## those terms.
 
 
-import pkg/upraises
-push: {.upraises: [].}
+{.push raises: [].}
 
 import pkg/chronos
 import pkg/libp2p
@@ -37,13 +36,16 @@ type
 method getBlock*(self: NetworkStore, address: BlockAddress): Future[?!Block] {.async.} =
   trace "Getting block from local store or network", address
 
-  without blk =? await self.localStore.getBlock(address), error:
-    if not (error of BlockNotFoundError): return failure error
-    trace "Block not in local store", address
+  without blk =? (await self.localStore.getBlock(address)), err:
+    if not (err of BlockNotFoundError):
+      trace "Error getting block from local store", address, err = err.msg
+      return failure err
 
-    without newBlock =? (await self.engine.requestBlock(address)).catch, error:
-      trace "Unable to get block from exchange engine", address
-      return failure error
+    trace "Block not in local store", address, err = err.msg
+
+    without newBlock =? (await self.engine.requestBlock(address)), err:
+      trace "Unable to get block from exchange engine", address, err = err.msg
+      return failure err
 
     return success newBlock
 
@@ -166,6 +168,4 @@ proc new*(
 ): NetworkStore =
   ## Create new instance of a NetworkStore
   ##
-  NetworkStore(
-      localStore: localStore,
-      engine: engine)
+  NetworkStore(localStore: localStore, engine: engine)
diff --git a/codex/utils/poseidon2digest.nim b/codex/utils/poseidon2digest.nim
index 56f072cd..efdb3c6a 100644
--- a/codex/utils/poseidon2digest.nim
+++ b/codex/utils/poseidon2digest.nim
@@ -12,10 +12,6 @@ import pkg/questionable/results
 import pkg/libp2p/multihash
 import pkg/stew/byteutils
 
-import pkg/constantine/math/arithmetic
-import pkg/constantine/math/io/io_bigints
-import pkg/constantine/math/io/io_fields
-
 import ../merkletree
 
 func spongeDigest*(
diff --git a/config.nims b/config.nims
index f04255ba..45830fad 100644
--- a/config.nims
+++ b/config.nims
@@ -74,6 +74,8 @@ else:
 --styleCheck:usages
 --styleCheck:error
 --maxLoopIterationsVM:1000000000
+--fieldChecks:on
+--warningAsError:"ProveField:on"
 
 when (NimMajor, NimMinor) >= (1, 4):
   --warning:"ObservableStores:off"
diff --git a/tests/circuits/fixtures/proof_main.circom b/tests/circuits/fixtures/proof_main.circom
deleted file mode 100644
index 1018d4bc..00000000
--- a/tests/circuits/fixtures/proof_main.circom
+++ /dev/null
@@ -1,4 +0,0 @@
-pragma circom 2.0.0;
-include "sample_cells.circom";
-// SampleAndProven( maxDepth, maxLog2NSlots, blockTreeDepth, nFieldElemsPerCell, nSamples )
-component main {public [entropy,dataSetRoot,slotIndex]} = SampleAndProve(32, 8, 5, 67, 5);
diff --git a/tests/codex/blockexchange/engine/testblockexc.nim b/tests/codex/blockexchange/engine/testblockexc.nim
index 4f1baf75..105f3a8e 100644
--- a/tests/codex/blockexchange/engine/testblockexc.nim
+++ b/tests/codex/blockexchange/engine/testblockexc.nim
@@ -278,7 +278,7 @@ asyncchecksuite "NetworkStore - multiple nodes":
     # As soon as we connect the downloader to the blockHolder, the block should
     # propagate to the downloader...
     await connectNodes(@[downloader, blockHolder])
-    check (await blockRequest).cid == aBlock.cid
+    check (await blockRequest).tryGet().cid == aBlock.cid
     check (await downloader.engine.localStore.hasBlock(aBlock.cid)).tryGet()
 
     # ... and the bystander should have cancelled the want-have
diff --git a/tests/codex/helpers.nim b/tests/codex/helpers.nim
index 9192968c..89aeafd1 100644
--- a/tests/codex/helpers.nim
+++ b/tests/codex/helpers.nim
@@ -31,7 +31,7 @@ func `==`*(a, b: Block): bool =
 proc calcEcBlocksCount*(blocksCount: int, ecK, ecM: int): int =
   let
     rounded = roundUp(blocksCount, ecK)
-    steps = divUp(blocksCount, ecK)
+    steps = divUp(rounded, ecK)
 
   rounded + (steps * ecM)
 
diff --git a/tests/codex/helpers/mockmarket.nim b/tests/codex/helpers/mockmarket.nim
index db84b208..5b8dd894 100644
--- a/tests/codex/helpers/mockmarket.nim
+++ b/tests/codex/helpers/mockmarket.nim
@@ -29,6 +29,7 @@ type
     markedAsMissingProofs*: seq[SlotId]
     canBeMarkedAsMissing: HashSet[SlotId]
     withdrawn*: seq[RequestId]
+    proofPointer*: uint8
     proofsRequired: HashSet[SlotId]
     proofsToBeRequired: HashSet[SlotId]
     proofChallenge*: ProofChallenge
@@ -117,7 +118,7 @@ method proofDowntime*(market: MockMarket): Future[uint8] {.async.} =
   return market.config.proofs.downtime
 
 method getPointer*(market: MockMarket, slotId: SlotId): Future[uint8] {.async.} =
-  return 0 # TODO
+  return market.proofPointer
 
 method requestStorage*(market: MockMarket, request: StorageRequest) {.async.} =
   market.requested.add(request)
diff --git a/tests/codex/node/helpers.nim b/tests/codex/node/helpers.nim
index e86c9613..5dd020ab 100644
--- a/tests/codex/node/helpers.nim
+++ b/tests/codex/node/helpers.nim
@@ -6,6 +6,7 @@ import pkg/chronos
 
 import pkg/codex/codextypes
 import pkg/codex/chunker
+import pkg/codex/slots
 
 import ../../asynctest
 
@@ -91,7 +92,12 @@ template setupAndTearDown*() {.dirty.} =
     discovery = DiscoveryEngine.new(localStore, peerStore, network, blockDiscovery, pendingBlocks)
     engine = BlockExcEngine.new(localStore, wallet, network, discovery, peerStore, pendingBlocks)
     store = NetworkStore.new(engine, localStore)
-    node = CodexNodeRef.new(switch, store, engine, blockDiscovery)
+    node = CodexNodeRef.new(
+      switch = switch,
+      networkStore = store,
+      engine = engine,
+      prover = Prover.none,
+      discovery = blockDiscovery)
 
     await node.start()
 
diff --git a/tests/codex/node/testnode.nim b/tests/codex/node/testnode.nim
index bf444a48..2338085c 100644
--- a/tests/codex/node/testnode.nim
+++ b/tests/codex/node/testnode.nim
@@ -120,11 +120,11 @@ asyncchecksuite "Test Node - Basic":
 
   test "Setup purchase request":
     let
+      erasure = Erasure.new(store, leoEncoderProvider, leoDecoderProvider)
       manifest = await storeDataGetManifest(localStore, chunker)
       manifestBlock = bt.Block.new(
         manifest.encode().tryGet(),
         codec = ManifestCodec).tryGet()
-      erasure = Erasure.new(store, leoEncoderProvider, leoDecoderProvider)
       protected = (await erasure.encode(manifest, 3, 2)).tryGet()
       builder = Poseidon2Builder.new(localStore, protected).tryGet()
       verifiable = (await builder.buildManifest()).tryGet()
diff --git a/tests/codex/sales/helpers/periods.nim b/tests/codex/sales/helpers/periods.nim
new file mode 100644
index 00000000..ba1793c2
--- /dev/null
+++ b/tests/codex/sales/helpers/periods.nim
@@ -0,0 +1,8 @@
+import pkg/codex/market
+import ../../helpers/mockclock
+
+proc advanceToNextPeriod*(clock: MockClock, market: Market) {.async.} =
+  let periodicity = await market.periodicity()
+  let period = periodicity.periodOf(clock.now().u256)
+  let periodEnd = periodicity.periodEnd(period)
+  clock.set((periodEnd + 1).truncate(int))
diff --git a/tests/codex/sales/states/testinitialproving.nim b/tests/codex/sales/states/testinitialproving.nim
index 0659edd3..69355567 100644
--- a/tests/codex/sales/states/testinitialproving.nim
+++ b/tests/codex/sales/states/testinitialproving.nim
@@ -14,12 +14,15 @@ import ../../../asynctest
 import ../../examples
 import ../../helpers
 import ../../helpers/mockmarket
+import ../../helpers/mockclock
+import ../helpers/periods
 
 asyncchecksuite "sales state 'initialproving'":
   let proof = Groth16Proof.example
   let request = StorageRequest.example
   let slotIndex = (request.ask.slots div 2).u256
   let market = MockMarket.new()
+  let clock = MockClock.new()
 
   var state: SaleInitialProving
   var agent: SalesAgent
@@ -31,7 +34,8 @@ asyncchecksuite "sales state 'initialproving'":
                           return success(proof)
     let context = SalesContext(
       onProve: onProve.some,
-      market: market
+      market: market,
+      clock: clock
     )
     agent = newSalesAgent(context,
                           request.id,
@@ -39,6 +43,12 @@ asyncchecksuite "sales state 'initialproving'":
                           request.some)
     state = SaleInitialProving.new()
 
+  proc allowProofToStart {.async.} =
+    # wait until we're in initialproving state
+    await sleepAsync(10.millis)
+    # it won't start proving until the next period
+    await clock.advanceToNextPeriod(market)
+
   test "switches to cancelled state when request expires":
     let next = state.onCancelled(request)
     check !next of SaleCancelled
@@ -47,30 +57,57 @@ asyncchecksuite "sales state 'initialproving'":
     let next = state.onFailed(request)
     check !next of SaleFailed
 
-  test "switches to filling state when initial proving is complete":
-    let next = await state.run(agent)
-    check !next of SaleFilling
-    check SaleFilling(!next).proof == proof
+  test "waits for the beginning of the period to get the challenge":
+    let future = state.run(agent)
+    await sleepAsync(10.millis)
+    check not future.finished
+    await allowProofToStart()
+    discard await future
+
+  test "waits another period when the proof pointer is about to wrap around":
+    market.proofPointer = 250
+    let future = state.run(agent)
+    await allowProofToStart()
+    await sleepAsync(10.millis)
+    check not future.finished
+    market.proofPointer = 100
+    await allowProofToStart()
+    discard await future
 
   test "onProve callback provides proof challenge":
     market.proofChallenge = ProofChallenge.example
 
     let future = state.run(agent)
+    await allowProofToStart()
+
+    discard await future
 
     check receivedChallenge == market.proofChallenge
 
+  test "switches to filling state when initial proving is complete":
+    let future = state.run(agent)
+    await allowProofToStart()
+    let next = await future
+
+    check !next of SaleFilling
+    check SaleFilling(!next).proof == proof
+
   test "switches to errored state when onProve callback fails":
     let onProveFailed: OnProve = proc(slot: Slot, challenge: ProofChallenge): Future[?!Groth16Proof] {.async.} =
       return failure("oh no!")
 
     let proofFailedContext = SalesContext(
       onProve: onProveFailed.some,
-      market: market
+      market: market,
+      clock: clock
     )
     agent = newSalesAgent(proofFailedContext,
                           request.id,
                           slotIndex,
                           request.some)
 
-    let next = await state.run(agent)
+    let future = state.run(agent)
+    await allowProofToStart()
+    let next = await future
+
     check !next of SaleErrored
diff --git a/tests/codex/sales/testsales.nim b/tests/codex/sales/testsales.nim
index 921ece83..b5fe4821 100644
--- a/tests/codex/sales/testsales.nim
+++ b/tests/codex/sales/testsales.nim
@@ -19,6 +19,7 @@ import ../helpers/mockmarket
 import ../helpers/mockclock
 import ../helpers/always
 import ../examples
+import ./helpers/periods
 
 asyncchecksuite "Sales - start":
   let proof = Groth16Proof.example
@@ -176,6 +177,12 @@ asyncchecksuite "Sales":
     await sales.stop()
     await repo.stop()
 
+  proc allowRequestToStart {.async.} =
+    # wait until we're in initialproving state
+    await sleepAsync(10.millis)
+    # it won't start proving until the next period
+    await clock.advanceToNextPeriod(market)
+
   proc getAvailability: Availability =
     let key = availability.id.key.get
     (waitFor reservations.get(key, Availability)).get
@@ -311,7 +318,8 @@ asyncchecksuite "Sales":
     createAvailability()
     let origSize = availability.size
     await market.requestStorage(request)
-    await sold # allow proving to start
+    await allowRequestToStart()
+    await sold
 
     # complete request
     market.slotState[request.slotId(slotIndex)] = SlotState.Finished
@@ -379,6 +387,8 @@ asyncchecksuite "Sales":
       saleFailed = true
     createAvailability()
     await market.requestStorage(request)
+    await allowRequestToStart()
+
     check eventually saleFailed
 
   test "makes storage available again when data retrieval fails":
@@ -400,12 +410,16 @@ asyncchecksuite "Sales":
       return success(Groth16Proof.example)
     createAvailability()
     await market.requestStorage(request)
+    await allowRequestToStart()
+
     check eventually provingRequest == request
     check provingSlot < request.ask.slots.u256
 
   test "fills a slot":
     createAvailability()
     await market.requestStorage(request)
+    await allowRequestToStart()
+
     check eventually market.filled.len > 0
     check market.filled[0].requestId == request.id
     check market.filled[0].slotIndex < request.ask.slots.u256
@@ -421,6 +435,8 @@ asyncchecksuite "Sales":
       soldSlotIndex = slotIndex
     createAvailability()
     await market.requestStorage(request)
+    await allowRequestToStart()
+
     check eventually soldRequest == request
     check soldSlotIndex < request.ask.slots.u256
 
@@ -437,6 +453,8 @@ asyncchecksuite "Sales":
       clearedSlotIndex = slotIndex
     createAvailability()
     await market.requestStorage(request)
+    await allowRequestToStart()
+
     check eventually clearedRequest == request
     check clearedSlotIndex < request.ask.slots.u256
 
diff --git a/tests/integration/nodes.nim b/tests/integration/nodes.nim
index 3a9e93cc..a60a55c7 100644
--- a/tests/integration/nodes.nim
+++ b/tests/integration/nodes.nim
@@ -46,7 +46,7 @@ proc waitUntilOutput*(node: NodeProcess, output: string) =
 
 proc waitUntilStarted*(node: NodeProcess) =
   if node.debug:
-    sleep(5_000)
+    sleep(10_000)
   else:
     node.waitUntilOutput("Started codex node")
 
diff --git a/tests/integration/testIntegration.nim b/tests/integration/testIntegration.nim
index 79d36513..88f27ffd 100644
--- a/tests/integration/testIntegration.nim
+++ b/tests/integration/testIntegration.nim
@@ -174,16 +174,25 @@ twonodessuite "Integration tests", debug1 = false, debug2 = false:
     check request.ask.maxSlotLoss == 0'u64
 
   test "nodes negotiate contracts on the marketplace":
-    let size = 0xFFFFF.u256
+    let size = 0xFFFFFF.u256
+    let data = await RandomChunker.example(blocks=8)
     # client 2 makes storage available
-    discard client2.postAvailability(size=size, duration=200.u256, minPrice=300.u256, maxCollateral=300.u256)
+    discard client2.postAvailability(size=size, duration=20*60.u256, minPrice=300.u256, maxCollateral=300.u256)
 
     # client 1 requests storage
-    let expiry = (await ethProvider.currentTime()) + 30
-    let cid = client1.upload("some file contents").get
-    let id = client1.requestStorage(cid, duration=100.u256, reward=400.u256, proofProbability=3.u256, expiry=expiry, collateral=200.u256).get
+    let expiry = (await ethProvider.currentTime()) + 5*60
+    let cid = client1.upload(data).get
+    let id = client1.requestStorage(
+      cid,
+      duration=10*60.u256,
+      reward=400.u256,
+      proofProbability=3.u256,
+      expiry=expiry,
+      collateral=200.u256,
+      nodes = 5,
+      tolerance = 2).get
 
-    check eventually client1.purchaseStateIs(id, "started")
+    check eventually(client1.purchaseStateIs(id, "started"), timeout=5*60*1000)
     let purchase = client1.getPurchase(id).get
     check purchase.error == none string
     let availabilities = client2.getAvailabilities().get
@@ -192,22 +201,33 @@ twonodessuite "Integration tests", debug1 = false, debug2 = false:
     check newSize > 0 and newSize < size
 
   test "node slots gets paid out":
+    let size = 0xFFFFFF.u256
+    let data = await RandomChunker.example(blocks = 8)
     let marketplace = Marketplace.new(Marketplace.address, ethProvider.getSigner())
     let tokenAddress = await marketplace.token()
     let token = Erc20Token.new(tokenAddress, ethProvider.getSigner())
     let reward = 400.u256
-    let duration = 100.u256
+    let duration = 10*60.u256
+    let nodes = 5'u
 
     # client 2 makes storage available
     let startBalance = await token.balanceOf(account2)
-    discard client2.postAvailability(size=0xFFFFF.u256, duration=200.u256, minPrice=300.u256, maxCollateral=300.u256).get
+    discard client2.postAvailability(size=size, duration=20*60.u256, minPrice=300.u256, maxCollateral=300.u256).get
 
     # client 1 requests storage
-    let expiry = (await ethProvider.currentTime()) + 30
-    let cid = client1.upload("some file contents").get
-    let id = client1.requestStorage(cid, duration=duration, reward=reward, proofProbability=3.u256, expiry=expiry, collateral=200.u256).get
+    let expiry = (await ethProvider.currentTime()) + 5*60
+    let cid = client1.upload(data).get
+    let id = client1.requestStorage(
+      cid,
+      duration=duration,
+      reward=reward,
+      proofProbability=3.u256,
+      expiry=expiry,
+      collateral=200.u256,
+      nodes = nodes,
+      tolerance = 2).get
 
-    check eventually client1.purchaseStateIs(id, "started")
+    check eventually(client1.purchaseStateIs(id, "started"), timeout=5*60*1000)
     let purchase = client1.getPurchase(id).get
     check purchase.error == none string
 
@@ -216,7 +236,7 @@ twonodessuite "Integration tests", debug1 = false, debug2 = false:
     # only with new transaction
     await ethProvider.advanceTime(duration)
 
-    check eventually (await token.balanceOf(account2)) - startBalance == duration*reward
+    check eventually (await token.balanceOf(account2)) - startBalance == duration*reward*nodes.u256
 
   test "request storage fails if nodes and tolerance aren't correct":
     let cid = client1.upload("some file contents").get