diff --git a/lib/ecto_foundationdb/layer/index_inventory.ex b/lib/ecto_foundationdb/layer/index_inventory.ex
index 2c684ea..ab6c5da 100644
--- a/lib/ecto_foundationdb/layer/index_inventory.ex
+++ b/lib/ecto_foundationdb/layer/index_inventory.ex
@@ -289,17 +289,17 @@ defmodule EctoFoundationDB.Layer.IndexInventory do
   defp tx_idxs_get_wait(tenant, tx, _adapter_opts, source, max_version_future, claim_future) do
     {start_key, end_key} = idx_range(tenant, source)
 
+    idxs_future = :erlfdb.get_range(tx, start_key, end_key, wait: false)
+
+    [max_version, claim, idxs] =
+      :erlfdb.wait_for_all_interleaving(tx, [max_version_future, claim_future, idxs_future])
+
     idxs =
-      tx
-      |> :erlfdb.get_range(start_key, end_key, wait: true)
+      idxs
       |> Enum.map(fn {_, fdb_value} -> Pack.from_fdb_value(fdb_value) end)
       # high priority first
       |> Enum.sort(&(Keyword.get(&1, :priority, 0) > Keyword.get(&2, :priority, 0)))
 
-    max_version = :erlfdb.wait(max_version_future)
-
-    claim = :erlfdb.wait(claim_future)
-
     case get_partial_idxs(claim, source) do
       {claim_active?, []} ->
         {MaxValue.decode(max_version), idxs, [], fn -> not claim_active? end}
diff --git a/mix.exs b/mix.exs
index 731150b..a3b0ce3 100644
--- a/mix.exs
+++ b/mix.exs
@@ -49,10 +49,13 @@ defmodule EctoFoundationdb.MixProject do
   # Run "mix help compile.app" to learn about applications.
   def application do
     [
-      extra_applications: [:logger]
+      extra_applications: extra_applications(Mix.env())
     ]
   end
 
+  defp extra_applications(:test), do: [:logger, :runtime_tools]
+  defp extra_applications(_), do: [:logger]
+
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
diff --git a/test/ecto/integration/crud_test.exs b/test/ecto/integration/crud_test.exs
index d2bb0ea..87e62a4 100644
--- a/test/ecto/integration/crud_test.exs
+++ b/test/ecto/integration/crud_test.exs
@@ -174,7 +174,7 @@ defmodule Ecto.Integration.CrudTest do
     test "tx_insert", context do
       tenant = context[:tenant]
 
-      # Operations inside a FoundationDB Adapater Transaction have the tenant applied
+      # Operations inside a FoundationDB Adapter Transaction have the tenant applied
       # automatically.
       user =
         TestRepo.transaction(
diff --git a/test/ecto/integration/fdb_api_counting_test.exs b/test/ecto/integration/fdb_api_counting_test.exs
new file mode 100644
index 0000000..b6dd33c
--- /dev/null
+++ b/test/ecto/integration/fdb_api_counting_test.exs
@@ -0,0 +1,347 @@
+defmodule Ecto.Integration.FdbApiCountingTest do
+  use Ecto.Integration.Case, async: false
+
+  alias Ecto.Adapters.FoundationDB
+  alias Ecto.Integration.TestRepo
+
+  alias EctoFoundationDB.Schemas.User
+
+  # This module tracks all calls from modules that begin with EctoFoundationDB.* to the following
+  # list of :erlfdb exported functions. If there are new relevant functions to track, they must be
+  # added here.
+  #
+  # By counting and documenting FDB API function calls, we can ensure new calls don't creep in unnoticed,
+  # and we can provide some explanatory documentation about how the Layer works.
+  @traced_calls [
+    {:erlfdb, :get, 2},
+    {:erlfdb, :get_range, 4},
+    {:erlfdb, :wait, 1},
+    {:erlfdb, :wait_for_any, 1},
+    {:erlfdb, :set, 3},
+    {:erlfdb, :clear, 2},
+    {:erlfdb, :clear_range, 3},
+    {:erlfdb, :max, 3},
+    {:erlfdb, :fold_range, 5},
+    {:erlfdb, :get_mapped_range, 5},
+    {:erlfdb, :wait_for_all, 1},
+    {:erlfdb, :watch, 2},
+    {:erlfdb, :wait_for_all_interleaving, 2}
+  ]
+
+  def start_trace(target) do
+    tracer = spawn(fn -> trace_listener([]) end)
+    trace_flags = [:call, :arity]
+    match_spec = [{:_, [], [{:message, {{:cp, {:caller}}}}]}]
+    :erlang.trace_pattern(:on_load, match_spec, [:local])
+    :erlang.trace_pattern({:erlfdb, :_, :_}, match_spec, [:local])
+    :erlang.trace(target, true, [{:tracer, tracer} | trace_flags])
+    tracer
+  end
+
+  def stop_trace(tracer, target) do
+    :erlang.trace(target, false, [:all])
+    :erlang.send(tracer, {:dump, self()})
+
+    ret =
+      receive do
+        {:acc, acc} ->
+          {:ok, Enum.reverse(acc)}
+      after
+        5000 -> {:error, :timeout}
+      end
+
+    Process.exit(tracer, :normal)
+    ret
+  end
+
+  defp trace_listener(acc) do
+    receive do
+      {:dump, pid} ->
+        :erlang.send(pid, {:acc, acc})
+
+      {:trace, _pid, :call, {:erlfdb, fun, arity}, {:cp, {caller, _, _}}} ->
+        try do
+          case Module.split(caller) do
+            ["EctoFoundationDB" | _] ->
+              if Enum.member?(@traced_calls, {:erlfdb, fun, arity}) do
+                trace_listener([{caller, fun} | acc])
+              else
+                trace_listener(acc)
+              end
+
+            _ ->
+              trace_listener(acc)
+          end
+        rescue
+          _e in ArgumentError ->
+            trace_listener(acc)
+        end
+
+      _term ->
+        trace_listener(acc)
+    end
+  end
+
+  def with_erlfdb_calls(fun) do
+    tracer = start_trace(self())
+    res = fun.()
+    {:ok, calls} = stop_trace(tracer, self())
+    {calls, res}
+  end
+
+  test "counting", context do
+    tenant = context[:tenant]
+
+    # =================================================================
+    # Insert (no index inventory cache)
+    # =================================================================
+
+    {calls, alice} =
+      with_erlfdb_calls(fn ->
+        {:ok, alice} =
+          %User{name: "Alice"}
+          |> FoundationDB.usetenant(tenant)
+          |> TestRepo.insert()
+
+        alice
+      end)
+
+    assert [
+             # get max_version
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # get source claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # there is no cache, so get idxs
+             {EctoFoundationDB.Layer.IndexInventory, :get_range},
+
+             # wait for max_version, claim_key, and idxs range
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all_interleaving},
+
+             # check for existence of primary write
+             {EctoFoundationDB.Layer.Tx, :get},
+
+             # wait for existence check
+             {EctoFoundationDB.Layer.Tx, :wait_for_any},
+
+             # primary write
+             {EctoFoundationDB.Layer.TxInsert, :set},
+
+             # index write
+             {EctoFoundationDB.Indexer.Default, :set}
+           ] == calls
+
+    # =================================================================
+    # Insert (with index inventory cache)
+    # =================================================================
+
+    {calls, _bob} =
+      with_erlfdb_calls(fn ->
+        {:ok, bob} =
+          %User{name: "Bob"}
+          |> FoundationDB.usetenant(tenant)
+          |> TestRepo.insert()
+
+        bob
+      end)
+
+    assert [
+             # get max_version and claim_key. We have cached the inventory, so
+             # these waits are deferred optimistically.
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # check for existence of primary write
+             {EctoFoundationDB.Layer.Tx, :get},
+             {EctoFoundationDB.Layer.Tx, :wait_for_any},
+
+             # primary write, index write
+             {EctoFoundationDB.Layer.TxInsert, :set},
+             {EctoFoundationDB.Indexer.Default, :set},
+
+             # wait for max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all}
+           ] == calls
+
+    # =================================================================
+    # Get using primary id
+    # =================================================================
+
+    {calls, _} =
+      with_erlfdb_calls(fn ->
+        TestRepo.get(User, alice.id, prefix: tenant)
+      end)
+
+    assert [
+             # get max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # get and wait primary write key
+             {EctoFoundationDB.Layer.Query, :get},
+             {EctoFoundationDB.Future, :wait_for_all_interleaving},
+
+             # wait for max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all}
+           ] = calls
+
+    # =================================================================
+    # Update an indexed field
+    # =================================================================
+
+    {calls, _} =
+      with_erlfdb_calls(fn ->
+        changeset = User.changeset(alice, %{name: "Alicia"})
+        {:ok, _} = TestRepo.update(changeset)
+      end)
+
+    assert [
+             # get max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # get and wait for existing data from primary write
+             {EctoFoundationDB.Layer.Tx, :get},
+             {EctoFoundationDB.Layer.Tx, :wait_for_any},
+
+             # set data in primary write
+             {EctoFoundationDB.Layer.Tx, :set},
+
+             # clear and set default index. :name has changed
+             {EctoFoundationDB.Indexer.Default, :clear},
+             {EctoFoundationDB.Indexer.Default, :set},
+
+             # wait for max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all}
+           ] == calls
+
+    # =================================================================
+    # Update an non-indexed field
+    # =================================================================
+
+    {calls, _} =
+      with_erlfdb_calls(fn ->
+        changeset = User.changeset(alice, %{notes: "Hello world"})
+        {:ok, _} = TestRepo.update(changeset)
+      end)
+
+    assert [
+             # get max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # get and wait for existing data from primary write
+             {EctoFoundationDB.Layer.Tx, :get},
+             {EctoFoundationDB.Layer.Tx, :wait_for_any},
+
+             # set data in primary write
+             {EctoFoundationDB.Layer.Tx, :set},
+
+             # clear and set default index. @todo, no index has changed, this is write amplification (#25)
+             {EctoFoundationDB.Indexer.Default, :clear},
+             {EctoFoundationDB.Indexer.Default, :set},
+
+             # wait for max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all}
+           ] == calls
+
+    # =================================================================
+    # Get by indexed field
+    # =================================================================
+
+    {calls, _} =
+      with_erlfdb_calls(fn ->
+        TestRepo.get_by(User, [name: "Alicia"], prefix: tenant)
+      end)
+
+    assert [
+             # get max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # get_mapped_range for :name index. The call to :get_range shown here
+             # is a tail call from get_mapped_range, so it's expected and harmless
+             {EctoFoundationDB.Layer.Query, :get_mapped_range},
+             {EctoFoundationDB.Layer.Query, :get_range},
+
+             # wait for get_mapped_range result
+             {EctoFoundationDB.Future, :wait_for_all_interleaving},
+
+             # wait for max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all}
+           ] == calls
+
+    # =================================================================
+    # Async get by indexed field
+    # =================================================================
+
+    {calls, _} =
+      with_erlfdb_calls(fn ->
+        TestRepo.transaction(
+          fn ->
+            f1 = TestRepo.async_get_by(User, name: "Alicia")
+            f2 = TestRepo.async_get_by(User, name: "Bob")
+            TestRepo.await([f1, f2])
+          end,
+          prefix: tenant
+        )
+      end)
+
+    assert [
+             # get max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # get_mapped_range for :name index
+             {EctoFoundationDB.Layer.Query, :get_mapped_range},
+             {EctoFoundationDB.Layer.Query, :get_range},
+
+             # wait for max_version and claim_key, @todo ideally this happens at the very end (#26)
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all},
+
+             # get max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # get_mapped_range for :name index
+             {EctoFoundationDB.Layer.Query, :get_mapped_range},
+             {EctoFoundationDB.Layer.Query, :get_range},
+
+             # max_version and claim_key again. FDB implements a RWY-transaction, so
+             # this trivially reads from local memory
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all},
+
+             # wait for results of both get_mapped_range calls
+             {EctoFoundationDB.Future, :wait_for_all_interleaving}
+           ] == calls
+
+    # =================================================================
+    # Delete
+    # =================================================================
+
+    {calls, _} =
+      with_erlfdb_calls(fn ->
+        {:ok, _} = TestRepo.delete(alice)
+      end)
+
+    assert [
+             # get max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+             {EctoFoundationDB.Layer.IndexInventory, :get},
+
+             # check for existence
+             {EctoFoundationDB.Layer.Tx, :get},
+             {EctoFoundationDB.Layer.Tx, :wait_for_any},
+
+             # clear primary write
+             {EctoFoundationDB.Layer.Tx, :clear},
+
+             # clear :name index
+             {EctoFoundationDB.Indexer.Default, :clear},
+
+             # wait for max_version and claim_key
+             {EctoFoundationDB.Layer.IndexInventory, :wait_for_all}
+           ] == calls
+  end
+end
diff --git a/test/support/schemas/user.ex b/test/support/schemas/user.ex
index da3148f..05503e6 100644
--- a/test/support/schemas/user.ex
+++ b/test/support/schemas/user.ex
@@ -9,13 +9,14 @@ defmodule EctoFoundationDB.Schemas.User do
 
   schema "users" do
     field(:name, :string)
+    field(:notes, :string)
 
     timestamps()
   end
 
   def changeset(struct, attrs) do
     struct
-    |> cast(attrs, [:name])
+    |> cast(attrs, [:name, :notes])
     |> validate_required([:name])
   end
 end