diff --git a/codexcrawler/components/crawler.nim b/codexcrawler/components/crawler.nim
index e86de85..0f984a0 100644
--- a/codexcrawler/components/crawler.nim
+++ b/codexcrawler/components/crawler.nim
@@ -3,86 +3,53 @@ import pkg/chronos
 import pkg/questionable
 import pkg/questionable/results
 
-import ./dht
-import ../list
+import ../services/dht
+import ./todolist
 import ../config
-import ../component
 import ../types
+import ../component
 import ../state
 import ../utils/asyncdataevent
 
-import std/sequtils
-
 logScope:
   topics = "crawler"
 
 type Crawler* = ref object of Component
+  state: State
   dht: Dht
-  config: Config
-  todoNodes: List
-  okNodes: List
-  nokNodes: List
+  todo: TodoList
 
-# This is not going to stay this way.
-proc isNew(c: Crawler, node: Node): bool =
-  not c.todoNodes.contains(node.id) and not c.okNodes.contains(node.id) and
-    not c.nokNodes.contains(node.id)
+proc raiseCheckEvent(c: Crawler, nid: Nid, success: bool): Future[?!void] {.async: (raises: []).} =
+  let event = DhtNodeCheckEventData(
+    id: nid,
+    isOk: success
+  )
+  if err =? (await c.state.events.dhtNodeCheck.fire(event)).errorOption:
+    return failure(err)
+  return success()
 
-# proc handleNodeNotOk(c: Crawler, target: NodeEntry) {.async.} =
-#   if err =? (await c.nokNodes.add(target)).errorOption:
-#     error "Failed to add not-OK-node to list", err = err.msg
+proc step(c: Crawler): Future[?!void] {.async: (raises: []).} =
+  without nid =? (await c.todo.pop()), err:
+    return failure(err)
 
-# proc handleNodeOk(c: Crawler, target: NodeEntry) {.async.} =
-#   if err =? (await c.okNodes.add(target)).errorOption:
-#     error "Failed to add OK-node to list", err = err.msg
+  without response =? await c.dht.getNeighbors(nid), err:
+    return failure(err)
 
-# proc addNewTodoNode(c: Crawler, nodeId: NodeId): Future[?!void] {.async.} =
-#   let entry = NodeEntry(id: nodeId, lastVisit: 0)
-#   return await c.todoNodes.add(entry)
+  if err =? (await c.raiseCheckEvent(nid, response.isResponsive)).errorOption:
+    return failure(err)
 
-# proc addNewTodoNodes(c: Crawler, newNodes: seq[Node]) {.async.} =
-#   for node in newNodes:
-#     if err =? (await c.addNewTodoNode(node.id)).errorOption:
-#       error "Failed to add todo-node to list", err = err.msg
+  if err =? (await c.state.events.nodesFound.fire(response.nodeIds)).errorOption:
+    return failure(err)
 
-# proc step(c: Crawler) {.async.} =
-#   logScope:
-#     todo = $c.todoNodes.len
-#     ok = $c.okNodes.len
-#     nok = $c.nokNodes.len
-
-#   without var target =? (await c.todoNodes.pop()), err:
-#     error "Failed to get todo node", err = err.msg
-
-#   target.lastVisit = Moment.now().epochSeconds.uint64
-
-#   without receivedNodes =? (await c.dht.getNeighbors(target.id)), err:
-#     await c.handleNodeNotOk(target)
-#     return
-
-#   let newNodes = receivedNodes.filterIt(isNew(c, it))
-#   if newNodes.len > 0:
-#     trace "Discovered new nodes", newNodes = newNodes.len
-
-#   await c.handleNodeOk(target)
-#   await c.addNewTodoNodes(newNodes)
-
-#   # Don't log the status every loop:
-#   if (c.todoNodes.len mod 10) == 0:
-#     trace "Status"
-
-proc worker(c: Crawler) {.async.} =
-  try:
-    while true:
-      # await c.step()
-      await sleepAsync(c.config.stepDelayMs.millis)
-  except Exception as exc:
-    error "Exception in crawler worker", msg = exc.msg
-    quit QuitFailure
+  return success()
 
 method start*(c: Crawler): Future[?!void] {.async.} =
-  info "Starting crawler...", stepDelayMs = $c.config.stepDelayMs
-  asyncSpawn c.worker()
+  info "Starting crawler..."
+
+  proc onStep(): Future[?!void] {.async: (raises: []), gcsafe.} =
+    await c.step()
+  await c.state.whileRunning(onStep, c.state.config.stepDelayMs.milliseconds)
+
   return success()
 
 method stop*(c: Crawler): Future[?!void] {.async.} =
@@ -90,13 +57,12 @@ method stop*(c: Crawler): Future[?!void] {.async.} =
 
 proc new*(
     T: type Crawler,
+    state: State,
     dht: Dht,
-    # todoNodes: List,
-    # okNodes: List,
-    # nokNodes: List,
-    config: Config,
+    todo: TodoList
 ): Crawler =
   Crawler(
+    state: state,
     dht: dht,
-    config: config, # todoNodes: todoNodes, okNodes: okNodes, nokNodes: nokNodes, 
+    todo: todo
   )
diff --git a/codexcrawler/components/dhtmetrics.nim b/codexcrawler/components/dhtmetrics.nim
index 0ba6ca8..092abde 100644
--- a/codexcrawler/components/dhtmetrics.nim
+++ b/codexcrawler/components/dhtmetrics.nim
@@ -3,10 +3,9 @@ import pkg/chronos
 import pkg/questionable
 import pkg/questionable/results
 
-import ./dht
 import ../list
 import ../state
-import ../metrics
+import ../services/metrics
 import ../component
 import ../utils/asyncdataevent
 
diff --git a/codexcrawler/components/todolist.nim b/codexcrawler/components/todolist.nim
index 7eac856..0d55ccb 100644
--- a/codexcrawler/components/todolist.nim
+++ b/codexcrawler/components/todolist.nim
@@ -30,12 +30,15 @@ proc addNodes(t: TodoList, nids: seq[Nid]) =
     s.complete()
     t.emptySignal = Future[void].none
 
-proc pop*(t: TodoList): Future[?!Nid] {.async.} =
+method pop*(t: TodoList): Future[?!Nid] {.async: (raises: []), base.} =
   if t.nids.len < 1:
     trace "List is empty. Waiting for new items..."
     let signal = newFuture[void]("list.emptySignal")
     t.emptySignal = some(signal)
-    await signal.wait(1.hours)
+    try:
+      await signal.wait(1.hours)
+    except CatchableError as exc:
+      return failure(exc.msg)
     if t.nids.len < 1:
       return failure("TodoList is empty.")
 
@@ -63,5 +66,5 @@ method stop*(t: TodoList): Future[?!void] {.async.} =
 proc new*(_: type TodoList, state: State): TodoList =
   TodoList(nids: newSeq[Nid](), state: state, emptySignal: Future[void].none)
 
-proc createTodoList*(state: State): ?!TodoList =
-  success(TodoList.new(state))
+proc createTodoList*(state: State): TodoList =
+  TodoList.new(state)
diff --git a/codexcrawler/installer.nim b/codexcrawler/installer.nim
index dfd4575..e8a7fd5 100644
--- a/codexcrawler/installer.nim
+++ b/codexcrawler/installer.nim
@@ -2,9 +2,9 @@ import pkg/chronos
 import pkg/questionable/results
 
 import ./state
-import ./metrics
+import ./services/metrics
+import ./services/dht
 import ./component
-import ./components/dht
 import ./components/crawler
 import ./components/timetracker
 import ./components/nodestore
@@ -19,14 +19,18 @@ proc createComponents*(state: State): Future[?!seq[Component]] {.async.} =
   without nodeStore =? createNodeStore(state), err:
     return failure(err)
 
-  let metrics = createMetrics(state.config.metricsAddress, state.config.metricsPort)
+  let
+    metrics = createMetrics(state.config.metricsAddress, state.config.metricsPort)
+    todoList = createTodoList(state)
 
   without dhtMetrics =? createDhtMetrics(state, metrics), err:
     return failure(err)
 
+  components.add(todoList)
   components.add(nodeStore)
   components.add(dht)
-  components.add(Crawler.new(dht, state.config))
+  components.add(Crawler.new(state, dht, todoList))
   components.add(TimeTracker.new(state, nodeStore))
   components.add(dhtMetrics)
+  
   return success(components)
diff --git a/codexcrawler/components/dht.nim b/codexcrawler/services/dht.nim
similarity index 74%
rename from codexcrawler/components/dht.nim
rename to codexcrawler/services/dht.nim
index 565af1e..c1c777c 100644
--- a/codexcrawler/components/dht.nim
+++ b/codexcrawler/services/dht.nim
@@ -1,5 +1,6 @@
 import std/os
 import std/net
+import std/sequtils
 import pkg/chronicles
 import pkg/chronos
 import pkg/libp2p
@@ -11,63 +12,59 @@ from pkg/nimcrypto import keccak256
 import ../utils/keyutils
 import ../utils/datastoreutils
 import ../utils/rng
-import ../utils/asyncdataevent
 import ../component
 import ../state
+import ../types
 
 export discv5
 
 logScope:
   topics = "dht"
 
-type Dht* = ref object of Component
-  state: State
-  protocol*: discv5.Protocol
-  key: PrivateKey
-  peerId: PeerId
-  announceAddrs*: seq[MultiAddress]
-  providerRecord*: ?SignedPeerRecord
-  dhtRecord*: ?SignedPeerRecord
+type 
+  GetNeighborsResponse* = ref object
+    isResponsive*: bool
+    nodeIds*: seq[Nid]
 
-# proc toNodeId*(cid: Cid): NodeId =
-#   ## Cid to discovery id
-#   ##
-
-#   readUintBE[256](keccak256.digest(cid.data.buffer).data)
-
-# proc toNodeId*(host: ca.Address): NodeId =
-#   ## Eth address to discovery id
-#   ##
-
-#   readUintBE[256](keccak256.digest(host.toArray).data)
+  Dht* = ref object of Component
+    state: State
+    protocol*: discv5.Protocol
+    key: PrivateKey
+    peerId: PeerId
+    announceAddrs*: seq[MultiAddress]
+    providerRecord*: ?SignedPeerRecord
+    dhtRecord*: ?SignedPeerRecord
 
 proc getNode*(d: Dht, nodeId: NodeId): ?!Node =
   let node = d.protocol.getNode(nodeId)
   if node.isSome():
     return success(node.get())
-  return failure("Node not found for id: " & $(NodeId(nodeId)))
+  return failure("Node not found for id: " & nodeId.toHex())
 
-proc getRoutingTableNodeIds(d: Dht): seq[NodeId] =
-  var ids = newSeq[NodeId]()
+method getRoutingTableNodeIds*(d: Dht): seq[Nid] {.base.} =
+  var ids = newSeq[Nid]()
   for bucket in d.protocol.routingTable.buckets:
     for node in bucket.nodes:
       ids.add(node.id)
   return ids
 
-proc getNeighbors*(d: Dht, target: NodeId): Future[?!seq[Node]] {.async.} =
+method getNeighbors*(d: Dht, target: Nid): Future[?!GetNeighborsResponse] {.async: (raises: []), base.} =
   without node =? d.getNode(target), err:
     return failure(err)
 
   let distances = @[256.uint16]
-  let response = await d.protocol.findNode(node, distances)
+  try:
+    let response = await d.protocol.findNode(node, distances)
 
-  if response.isOk():
-    let nodes = response.get()
-    if nodes.len > 0:
-      return success(nodes)
-
-  # Both returning 0 nodes and a failure result are treated as failure of getNeighbors
-  return failure("No nodes returned")
+    if response.isOk():
+      let nodes = response.get()
+      return success(GetNeighborsResponse(
+        isResponsive: true,
+        nodeIds: nodes.mapIt(it.id))
+      )
+    return failure($response.error())
+  except CatchableError as exc:
+    return failure(exc.msg)
 
 proc findPeer*(d: Dht, peerId: PeerId): Future[?PeerRecord] {.async.} =
   trace "protocol.resolve..."
@@ -103,19 +100,19 @@ proc updateDhtRecord(d: Dht, addrs: openArray[MultiAddress]) =
   if not d.protocol.isNil:
     d.protocol.updateRecord(d.dhtRecord).expect("Should update SPR")
 
-proc findRoutingTableNodes(d: Dht) {.async.} =
-  await sleepAsync(5.seconds)
-  let nodes = d.getRoutingTableNodeIds()
+# proc findRoutingTableNodes(d: Dht) {.async.} =
+#   await sleepAsync(5.seconds)
+#   let nodes = d.getRoutingTableNodeIds()
 
-  if err =? (await d.state.events.nodesFound.fire(nodes)).errorOption:
-    error "Failed to raise routing-table nodes as found nodes", err = err.msg
-  else:
-    trace "Routing table nodes raise as found nodes", num = nodes.len
+#   if err =? (await d.state.events.nodesFound.fire(nodes)).errorOption:
+#     error "Failed to raise routing-table nodes as found nodes", err = err.msg
+#   else:
+#     trace "Routing table nodes raised as found nodes", num = nodes.len
 
 method start*(d: Dht): Future[?!void] {.async.} =
   d.protocol.open()
   await d.protocol.start()
-  asyncSpawn d.findRoutingTableNodes()
+  # asyncSpawn d.findRoutingTableNodes()
   return success()
 
 method stop*(d: Dht): Future[?!void] {.async.} =
diff --git a/codexcrawler/metrics.nim b/codexcrawler/services/metrics.nim
similarity index 100%
rename from codexcrawler/metrics.nim
rename to codexcrawler/services/metrics.nim
diff --git a/codexcrawler/state.nim b/codexcrawler/state.nim
index 5670ce9..5394ef1 100644
--- a/codexcrawler/state.nim
+++ b/codexcrawler/state.nim
@@ -40,4 +40,5 @@ method whileRunning*(s: State, step: OnStep, delay: Duration) {.async, base.} =
         s.status = ApplicationStatus.Stopping
       await sleepAsync(delay)
 
+  # todo this needs a delay because starts are still being called.
   asyncSpawn worker()
diff --git a/tests/codexcrawler/components/testcrawler.nim b/tests/codexcrawler/components/testcrawler.nim
new file mode 100644
index 0000000..2ec2948
--- /dev/null
+++ b/tests/codexcrawler/components/testcrawler.nim
@@ -0,0 +1,115 @@
+import pkg/chronos
+import pkg/questionable
+import pkg/questionable/results
+import pkg/asynctest/chronos/unittest
+
+import ../../../codexcrawler/components/crawler
+import ../../../codexcrawler/services/dht
+import ../../../codexcrawler/utils/asyncdataevent
+import ../../../codexcrawler/types
+import ../../../codexcrawler/state
+import ../mockstate
+import ../mockdht
+import ../mocktodolist
+import ../helpers
+
+suite "Crawler":
+  var
+    nid1: Nid
+    nid2: Nid
+    state: MockState
+    todo: MockTodoList
+    dht: MockDht
+    crawler: Crawler
+
+  setup:
+    nid1 = genNid()
+    nid2 = genNid()
+    state = createMockState()
+    todo = createMockTodoList()
+    dht = createMockDht()
+
+    crawler = Crawler.new(state, dht, todo)
+
+    (await crawler.start()).tryGet()
+
+  teardown:
+    (await crawler.stop()).tryGet()
+    state.checkAllUnsubscribed()
+
+  proc onStep() {.async.} = 
+    (await state.stepper()).tryGet()
+
+  proc responsive(nid: Nid): GetNeighborsResponse =
+    GetNeighborsResponse(
+      isResponsive: true,
+      nodeIds: @[nid]
+    )
+
+  proc unresponsive(nid: Nid): GetNeighborsResponse =
+    GetNeighborsResponse(
+      isResponsive: false,
+      nodeIds: @[nid]
+    )
+
+  test "onStep should pop a node from the todoList and getNeighbors for it":
+    todo.popReturn = success(nid1)
+    dht.getNeighborsReturn = success(responsive(nid1))
+
+    await onStep()
+
+    check:
+      !(dht.getNeighborsArg) == nid1
+
+  test "nodes returned by getNeighbors are raised as nodesFound":
+    var nodesFound = newSeq[Nid]()
+    proc onNodesFound(nids: seq[Nid]): Future[?!void] {.async.} =
+      nodesFound = nids
+      return success()
+    let sub = state.events.nodesFound.subscribe(onNodesFound)
+
+    todo.popReturn = success(nid1)
+    dht.getNeighborsReturn = success(responsive(nid2))
+
+    await onStep()
+
+    check:
+      nid2 in nodesFound
+
+    await state.events.nodesFound.unsubscribe(sub)
+
+  test "responsive result from getNeighbors raises the node as successful dhtNodeCheck":
+    var checkEvent = DhtNodeCheckEventData()
+    proc onCheck(event: DhtNodeCheckEventData): Future[?!void] {.async.} =
+      checkEvent = event
+      return success()
+    let sub = state.events.dhtNodeCheck.subscribe(onCheck)
+
+    todo.popReturn = success(nid1)
+    dht.getNeighborsReturn = success(responsive(nid2))
+
+    await onStep()
+
+    check:
+      checkEvent.id == nid1
+      checkEvent.isOk == true
+
+    await state.events.dhtNodeCheck.unsubscribe(sub)
+
+  test "unresponsive result from getNeighbors raises the node as unsuccessful dhtNodeCheck":
+    var checkEvent = DhtNodeCheckEventData()
+    proc onCheck(event: DhtNodeCheckEventData): Future[?!void] {.async.} =
+      checkEvent = event
+      return success()
+    let sub = state.events.dhtNodeCheck.subscribe(onCheck)
+
+    todo.popReturn = success(nid1)
+    dht.getNeighborsReturn = success(unresponsive(nid2))
+
+    await onStep()
+
+    check:
+      checkEvent.id == nid1
+      checkEvent.isOk == false
+
+    await state.events.dhtNodeCheck.unsubscribe(sub)
diff --git a/tests/codexcrawler/components/testtimetracker.nim b/tests/codexcrawler/components/testtimetracker.nim
index 83f1fb2..72666ff 100644
--- a/tests/codexcrawler/components/testtimetracker.nim
+++ b/tests/codexcrawler/components/testtimetracker.nim
@@ -44,6 +44,9 @@ suite "TimeTracker":
     await state.events.nodesExpired.unsubscribe(sub)
     state.checkAllUnsubscribed()
 
+  proc onStep() {.async.} = 
+    (await state.stepper()).tryGet()
+
   proc createNodeInStore(lastVisit: uint64): Nid =
     let entry = NodeEntry(id: genNid(), lastVisit: lastVisit)
     store.nodesToIterate.add(entry)
@@ -55,7 +58,7 @@ suite "TimeTracker":
         (Moment.now().epochSeconds - ((1 + state.config.revisitDelayMins) * 60)).uint64
       expiredNodeId = createNodeInStore(expiredTimestamp)
 
-    (await state.stepper()).tryGet()
+    await onStep()
 
     check:
       expiredNodeId in expiredNodesReceived
@@ -66,7 +69,7 @@ suite "TimeTracker":
         (Moment.now().epochSeconds - ((state.config.revisitDelayMins - 1) * 60)).uint64
       recentNodeId = createNodeInStore(recentTimestamp)
 
-    (await state.stepper()).tryGet()
+    await onStep()
 
     check:
       recentNodeId notin expiredNodesReceived
diff --git a/tests/codexcrawler/mockdht.nim b/tests/codexcrawler/mockdht.nim
new file mode 100644
index 0000000..98232ad
--- /dev/null
+++ b/tests/codexcrawler/mockdht.nim
@@ -0,0 +1,26 @@
+import pkg/chronos
+import pkg/questionable
+import pkg/questionable/results
+import ../../codexcrawler/services/dht
+import ../../codexcrawler/types
+
+type MockDht* = ref object of Dht
+  routingTable*: seq[Nid]
+  getNeighborsArg*: ?Nid
+  getNeighborsReturn*: ?!GetNeighborsResponse
+
+method getRoutingTableNodeIds*(d: MockDht): seq[Nid] =
+  return d.routingTable
+
+method getNeighbors*(d: MockDht, target: Nid): Future[?!GetNeighborsResponse] {.async: (raises: []).} =
+  d.getNeighborsArg = some(target)
+  return d.getNeighborsReturn
+
+method start*(d: MockDht): Future[?!void] {.async.} =
+  return success()
+
+method stop*(d: MockDht): Future[?!void] {.async.} =
+  return success()
+
+proc createMockDht*(): MockDht =
+  MockDht()
diff --git a/tests/codexcrawler/mockmetrics.nim b/tests/codexcrawler/mockmetrics.nim
index 021a8b0..16837b3 100644
--- a/tests/codexcrawler/mockmetrics.nim
+++ b/tests/codexcrawler/mockmetrics.nim
@@ -1,4 +1,4 @@
-import ../../codexcrawler/metrics
+import ../../codexcrawler/services/metrics
 
 type MockMetrics* = ref object of Metrics
   todo*: int
diff --git a/tests/codexcrawler/mockstate.nim b/tests/codexcrawler/mockstate.nim
index bfa7e6f..abc9594 100644
--- a/tests/codexcrawler/mockstate.nim
+++ b/tests/codexcrawler/mockstate.nim
@@ -7,6 +7,16 @@ import ../../codexcrawler/config
 type MockState* = ref object of State
   stepper*: OnStep
 
+proc checkAllUnsubscribed*(s: MockState) =
+  check:
+    s.events.nodesFound.listeners == 0
+    s.events.newNodesDiscovered.listeners == 0
+    s.events.dhtNodeCheck.listeners == 0
+    s.events.nodesExpired.listeners == 0
+
+method whileRunning*(s: MockState, step: OnStep, delay: Duration) {.async.} =
+  s.stepper = step
+
 proc createMockState*(): MockState =
   MockState(
     status: ApplicationStatus.Running,
@@ -18,13 +28,3 @@ proc createMockState*(): MockState =
       nodesExpired: newAsyncDataEvent[seq[Nid]](),
     ),
   )
-
-proc checkAllUnsubscribed*(s: MockState) =
-  check:
-    s.events.nodesFound.listeners == 0
-    s.events.newNodesDiscovered.listeners == 0
-    s.events.dhtNodeCheck.listeners == 0
-    s.events.nodesExpired.listeners == 0
-
-method whileRunning*(s: MockState, step: OnStep, delay: Duration) {.async.} =
-  s.stepper = step
diff --git a/tests/codexcrawler/mocktodolist.nim b/tests/codexcrawler/mocktodolist.nim
new file mode 100644
index 0000000..3ff9988
--- /dev/null
+++ b/tests/codexcrawler/mocktodolist.nim
@@ -0,0 +1,20 @@
+import pkg/chronos
+import pkg/questionable/results
+
+import ../../codexcrawler/components/todolist
+import ../../codexcrawler/types
+
+type MockTodoList* = ref object of TodoList
+  popReturn*: ?!Nid
+  
+method pop*(t: MockTodoList): Future[?!Nid] {.async: (raises: []).} =
+  return t.popReturn
+
+method start*(t: MockTodoList): Future[?!void] {.async.} =
+  return success()
+
+method stop*(t: MockTodoList): Future[?!void] {.async.} =
+  return success()
+
+proc createMockTodoList*(): MockTodoList =
+  MockTodoList()
diff --git a/tests/codexcrawler/testcomponents.nim b/tests/codexcrawler/testcomponents.nim
index 1b9a6b7..0773ec0 100644
--- a/tests/codexcrawler/testcomponents.nim
+++ b/tests/codexcrawler/testcomponents.nim
@@ -2,5 +2,6 @@ import ./components/testnodestore
 import ./components/testdhtmetrics
 import ./components/testtodolist
 import ./components/testtimetracker
+import ./components/testcrawler
 
 {.warning[UnusedImport]: off.}