diff --git a/test/test_entanglement_tracker.jl b/test/test_entanglement_tracker.jl
new file mode 100644
index 0000000..dbfb746
--- /dev/null
+++ b/test/test_entanglement_tracker.jl
@@ -0,0 +1,100 @@
+using Revise
+using QuantumSavory
+using ResumableFunctions
+using ConcurrentSim
+using QuantumSavory.ProtocolZoo
+using QuantumSavory.ProtocolZoo: EntanglementCounterpart, EntanglementHistory, EntanglementUpdateX, EntanglementUpdateZ
+using Graphs
+using Test
+
+using Logging
+logger = ConsoleLogger(Logging.Debug; meta_formatter=(args...)->(:black,"",""))
+global_logger(logger)
+
+##
+
+net = RegisterNet([Register(3), Register(4), Register(2), Register(3)])
+sim = get_time_tracker(net)
+
+
+entangler1 = EntanglerProt(sim, net, 1, 2; rounds=1)
+@process entangler1()
+run(sim, 20)
+
+@test net[1].tags == [[Tag(EntanglementCounterpart, 2, 1)],[],[]]
+
+
+entangler2 = EntanglerProt(sim, net, 2, 3; rounds=1)
+@process entangler2()
+run(sim, 40)
+entangler3 = EntanglerProt(sim, net, 4, 3; rounds=1)
+@process entangler3()
+run(sim, 60)
+
+@test net[1].tags == [[Tag(EntanglementCounterpart, 2, 1)],[],[]]
+@test net[2].tags == [[Tag(EntanglementCounterpart, 1, 1)],[Tag(EntanglementCounterpart, 3, 1)],[],[]]
+@test net[3].tags == [[Tag(EntanglementCounterpart, 2, 2)],[Tag(EntanglementCounterpart, 4, 1)]]
+@test net[4].tags == [[Tag(EntanglementCounterpart, 3, 2)],[],[]]
+
+@test [islocked(ref) for i in vertices(net) for ref in net[i]] |> any == false
+
+
+swapper2 = SwapperProt(sim, net, 2; rounds=1)
+swapper3 = SwapperProt(sim, net, 3; rounds=1)
+@process swapper2()
+@process swapper3()
+run(sim, 80)
+
+# In the absence of an entanglement tracker the tags will not all be updated
+@test net[1].tags == [[Tag(EntanglementCounterpart, 2, 1)],[],[]]
+@test net[2].tags == [[Tag(EntanglementHistory, 1, 1, 3, 1, 2)],[Tag(EntanglementHistory, 3, 1, 1, 1, 1)],[],[]]
+@test net[3].tags == [[Tag(EntanglementHistory, 2, 2, 4, 1, 2)],[Tag(EntanglementHistory, 4, 1, 2, 2, 1)]]
+@test net[4].tags == [[Tag(EntanglementCounterpart, 3, 2)],[],[]]
+
+@test isassigned(net[1][1]) && isassigned(net[4][1])
+#@test observable((net[1][1], net[4][1]), Z⊗Z) ≈ 1
+@test !isassigned(net[2][1]) && !isassigned(net[3][1])
+@test !isassigned(net[2][2]) && !isassigned(net[3][2])
+
+@test [islocked(ref) for i in vertices(net) for ref in net[i]] |> any == false
+
+
+##
+
+using Revise
+using QuantumSavory
+using ResumableFunctions
+using ConcurrentSim
+using QuantumSavory.ProtocolZoo
+using QuantumSavory.ProtocolZoo: EntanglementCounterpart, EntanglementHistory, EntanglementUpdateX, EntanglementUpdateZ
+using Graphs
+using Test
+using Random
+
+using Logging
+logger = ConsoleLogger(Logging.Debug; meta_formatter=(args...)->(:black,"",""))
+global_logger(logger)
+# same but this time with an entanglement tracker
+n = 5 # works at <5
+for i in 1:1000
+    println("new =======================\n\n")
+    net = RegisterNet([Register(i+3) for i in 1:n])
+    sim = get_time_tracker(net)
+    for i in vertices(net)
+        tracker = EntanglementTracker(sim, net, i)
+        @process tracker()
+    end
+    for e in edges(net)
+        eprot = EntanglerProt(sim, net, e.src, e.dst; rounds=1)
+        @process eprot()
+    end
+    for i in 2:n-1
+        swapper = SwapperProt(sim, net, i; rounds=1)
+        @process swapper()
+    end
+    run(sim, 200)
+
+    @test net[1].tags[1] == [Tag(EntanglementCounterpart, n, 1)]
+    @test net[n].tags[1] == [Tag(EntanglementCounterpart, 1, 1)]
+    #@test observable((net[1][1], net[n][1]), Z⊗Z) ≈ 1
+end