diff --git a/app/models/ai.rb b/app/models/ai.rb
new file mode 100644
index 000000000..4b4c17743
--- /dev/null
+++ b/app/models/ai.rb
@@ -0,0 +1,5 @@
+module Ai
+  def self.table_name_prefix
+    "ai_"
+  end
+end
diff --git a/app/models/ai/quota.rb b/app/models/ai/quota.rb
index 6ef4d7dc3..955a855af 100644
--- a/app/models/ai/quota.rb
+++ b/app/models/ai/quota.rb
@@ -1,18 +1,14 @@
 class Ai::Quota < ApplicationRecord
   class UsageExceedsQuotaError < StandardError; end
 
-  include MoneyAccessors, Resettable
-
-  self.table_name = "ai_quotas"
-
-  money_accessor :used, :limit
-
   belongs_to :user
 
+  before_create -> { reset }
+
   validates :limit, presence: true, numericality: { only_integer: true, greater_than_or_equal_to: 0 }
   validates :used, presence: true, numericality: { only_integer: true, greater_than_or_equal_to: 0 }
 
-  def increment_usage(cost)
+  def spend(cost)
     cost = Money.wrap(cost)
 
     transaction do
@@ -21,15 +17,34 @@ class Ai::Quota < ApplicationRecord
     end
   end
 
-  def ensure_under_limit
+  def ensure_not_depleted
     reset_if_due
 
-    if over_limit?
+    if depleted?
       raise UsageExceedsQuotaError
     end
   end
 
-  def over_limit?
-    used >= limit
-  end
+  private
+    def reset_if_due
+      reset if due_for_reset?
+    end
+
+    def reset
+      attributes = { used: 0, reset_at: 7.days.from_now }
+
+      if persisted?
+        update(**attributes)
+      else
+        assign_attributes(**attributes)
+      end
+    end
+
+    def due_for_reset?
+      reset_at.before?(Time.current)
+    end
+
+    def depleted?
+      used >= limit
+    end
 end
diff --git a/app/models/ai/quota/money.rb b/app/models/ai/quota/money.rb
index 2a22ec3b7..f229c8def 100644
--- a/app/models/ai/quota/money.rb
+++ b/app/models/ai/quota/money.rb
@@ -1,6 +1,4 @@
 class Ai::Quota::Money < Data.define(:value)
-  include Comparable
-
   CENTS_PER_DOLLAR = 100
   MICROCENTS_PER_CENT = 1_000_000
   MICROCENTS_PER_DOLLAR = CENTS_PER_DOLLAR * MICROCENTS_PER_CENT
@@ -24,9 +22,10 @@ class Ai::Quota::Money < Data.define(:value)
       new(microcents)
     end
 
-    def convert_dollars_to_microcents(dollars)
-      (dollars.to_d * MICROCENTS_PER_DOLLAR).round.to_i
-    end
+    private
+      def convert_dollars_to_microcents(dollars)
+        (dollars.to_d * MICROCENTS_PER_DOLLAR).round.to_i
+      end
   end
 
   def to_i
@@ -40,22 +39,4 @@ class Ai::Quota::Money < Data.define(:value)
   def in_dollars
     in_microcents.to_d / MICROCENTS_PER_DOLLAR
   end
-
-  def <=>(other)
-    in_microcents <=> self.class.wrap(other).in_microcents
-  end
-
-  def +(other)
-    other = self.class.wrap(other)
-    self.class.new(in_microcents + other.in_microcents)
-  end
-
-  def -(other)
-    other = self.class.wrap(other)
-    self.class.new(in_microcents - other.in_microcents)
-  end
-
-  def abs
-    self.class.new(in_microcents.abs)
-  end
 end
diff --git a/app/models/ai/quota/money_accessors.rb b/app/models/ai/quota/money_accessors.rb
deleted file mode 100644
index 28497a4d5..000000000
--- a/app/models/ai/quota/money_accessors.rb
+++ /dev/null
@@ -1,20 +0,0 @@
-module Ai::Quota::MoneyAccessors
-  extend ActiveSupport::Concern
-
-  class_methods do
-    def money_accessor(*attribute_names)
-      attribute_names.each do |name|
-        define_method(name) do
-          if super()
-            Ai::Quota::Money.new(super())
-          end
-        end
-
-        define_method("#{name}=") do |value|
-          value = Ai::Quota::Money.wrap(value).in_microcents if value
-          super(value)
-        end
-      end
-    end
-  end
-end
diff --git a/app/models/ai/quota/resettable.rb b/app/models/ai/quota/resettable.rb
deleted file mode 100644
index 497ea8b93..000000000
--- a/app/models/ai/quota/resettable.rb
+++ /dev/null
@@ -1,25 +0,0 @@
-module Ai::Quota::Resettable
-  extend ActiveSupport::Concern
-
-  included do
-    before_create -> { reset }
-  end
-
-  def reset_if_due
-    reset if due_for_reset?
-  end
-
-  def reset
-    attributes = { used: 0, reset_at: 7.days.from_now }
-
-    if persisted?
-      update(**attributes)
-    else
-      assign_attributes(**attributes)
-    end
-  end
-
-  def due_for_reset?
-    reset_at.before?(Time.current)
-  end
-end
diff --git a/app/models/conversation.rb b/app/models/conversation.rb
index 1d7cab876..bf3a4a0ab 100644
--- a/app/models/conversation.rb
+++ b/app/models/conversation.rb
@@ -9,7 +9,7 @@ class Conversation < ApplicationRecord
   enum :state, %w[ ready thinking ].index_by(&:itself), default: :ready
 
   def ask(question, **attributes)
-    user.ensure_under_ai_usage_limit
+    user.ensure_ai_quota_not_depleted
 
     create_message_with_state_change(**attributes, role: :user, content: question) do
       raise(InvalidStateError, "Can't ask questions while thinking") if thinking?
@@ -23,7 +23,7 @@ class Conversation < ApplicationRecord
       ready!
     end
 
-    user.increment_ai_usage(message.cost) if message.cost
+    user.spend_ai_quota(message.cost) if message.cost
 
     message
   end
diff --git a/app/models/user/ai_quota.rb b/app/models/user/ai_quota.rb
index 133759c71..01be7ae1c 100644
--- a/app/models/user/ai_quota.rb
+++ b/app/models/user/ai_quota.rb
@@ -5,15 +5,16 @@ module User::AiQuota
     has_one :ai_quota, class_name: "Ai::Quota"
   end
 
-  def fetch_or_create_ai_quota
-    ai_quota || create_ai_quota!(limit: Ai::Quota::Money.wrap("$100"))
+  def spend_ai_quota(cost)
+    fetch_or_create_ai_quota.spend(cost)
   end
 
-  def increment_ai_usage(cost)
-    fetch_or_create_ai_quota.increment_usage(cost)
+  def ensure_ai_quota_not_depleted
+    fetch_or_create_ai_quota.ensure_not_depleted
   end
 
-  def ensure_under_ai_usage_limit
-    fetch_or_create_ai_quota.ensure_under_limit
-  end
+  private
+    def fetch_or_create_ai_quota
+      ai_quota || create_ai_quota!(limit: Ai::Quota::Money.wrap("$100"))
+    end
 end
diff --git a/config/initializers/inflections.rb b/config/initializers/inflections.rb
index 3d2359e52..62ffe294f 100644
--- a/config/initializers/inflections.rb
+++ b/config/initializers/inflections.rb
@@ -13,4 +13,7 @@
 # These inflection rules are supported but not enabled by default:
 ActiveSupport::Inflector.inflections(:en) do |inflect|
   inflect.acronym "SQLite"
+
+  inflect.singular "quotas", "quota"
+  inflect.plural "quota", "quotas"
 end
diff --git a/test/models/ai/quota_test.rb b/test/models/ai/quota_test.rb
index 9d175b80d..b37e60ee9 100644
--- a/test/models/ai/quota_test.rb
+++ b/test/models/ai/quota_test.rb
@@ -2,7 +2,7 @@ require "test_helper"
 
 class Ai::QuotaTest < ActiveSupport::TestCase
   setup do
-    @quota = Ai::Quota.new(user: users(:jz), limit: "$100")
+    @quota = Ai::Quota.new(user: users(:jz), limit: Ai::Quota::Money.wrap("$100").in_microcents)
   end
 
   test "create" do
@@ -10,106 +10,54 @@ class Ai::QuotaTest < ActiveSupport::TestCase
 
     assert_in_delta 7.days.from_now, @quota.reset_at, 1.minute
     assert_equal 0, @quota.used
-    assert_equal Ai::Quota::Money.wrap("$100"), @quota.limit
-  end
-
-  test "accessors" do
-    @quota.limit = nil
-    assert_nil @quota.limit
-
-    @quota.limit = "$100"
-    assert_kind_of Ai::Quota::Money, @quota.limit
-    assert_equal Ai::Quota::Money.wrap("$100"), @quota.limit
-
-    @quota.used = nil
-    assert_nil @quota.used
-
-    @quota.used = "$100"
-    assert_kind_of Ai::Quota::Money, @quota.used
-    assert_equal Ai::Quota::Money.wrap("$100"), @quota.used
+    assert_equal Ai::Quota::Money.wrap("$100").in_microcents, @quota.limit
   end
 
   test "increment usage" do
     @quota.save
 
-    @quota.increment_usage("$100")
-    assert_equal Ai::Quota::Money.wrap("$100"), @quota.used
-    @quota.increment_usage("$500")
-    assert_equal Ai::Quota::Money.wrap("$600"), @quota.used
-    @quota.increment_usage("$1000")
-    assert_equal Ai::Quota::Money.wrap("$1600"), @quota.used
-    @quota.increment_usage("$5000")
-    assert_equal Ai::Quota::Money.wrap("$6600"), @quota.used
-    @quota.increment_usage("$10000")
-    assert_equal Ai::Quota::Money.wrap("$16600"), @quota.used
+    @quota.spend("$100")
+    assert_equal Ai::Quota::Money.wrap("$100").in_microcents, @quota.used
+    @quota.spend("$500")
+    assert_equal Ai::Quota::Money.wrap("$600").in_microcents, @quota.used
+    @quota.spend("$1000")
+    assert_equal Ai::Quota::Money.wrap("$1600").in_microcents, @quota.used
+    @quota.spend("$5000")
+    assert_equal Ai::Quota::Money.wrap("$6600").in_microcents, @quota.used
+    @quota.spend("$10000")
+    assert_equal Ai::Quota::Money.wrap("$16600").in_microcents, @quota.used
 
-    @quota.reset
-    assert_equal Ai::Quota::Money.wrap("$0"), @quota.used
-    assert_in_delta 7.days.from_now, @quota.reset_at, 1.minute
+    @quota.used = 0
 
-    @quota.increment_usage("$10")
-    assert_equal Ai::Quota::Money.wrap("$10"), @quota.used
+    @quota.spend("$10")
+    assert_equal Ai::Quota::Money.wrap("$10").in_microcents, @quota.used
     assert_in_delta 7.days.from_now, @quota.reset_at, 1.minute
 
     travel 2.days
 
-    @quota.increment_usage("$5")
-    assert_equal Ai::Quota::Money.wrap("$15"), @quota.used
+    @quota.spend("$5")
+    assert_equal Ai::Quota::Money.wrap("$15").in_microcents, @quota.used
     assert_in_delta 5.days.from_now, @quota.reset_at, 1.minute
 
     travel 8.days
 
-    @quota.increment_usage("$5")
-    assert_equal Ai::Quota::Money.wrap("$5"), @quota.used
+    @quota.spend("$5")
+    assert_equal Ai::Quota::Money.wrap("$5").in_microcents, @quota.used
     assert_in_delta 7.days.from_now, @quota.reset_at, 1.minute
   end
 
   test "limit checks" do
     @quota.save
 
-    @quota.used = "$0"
-    assert_not @quota.over_limit?
+    @quota.used = 0
+    @quota.ensure_not_depleted
 
-    @quota.used = "$300"
-    assert @quota.over_limit?
-
-    @quota.used = "$0"
-    @quota.ensure_under_limit
-
-    @quota.used = "$300"
+    @quota.used = Ai::Quota::Money.wrap("$300").in_microcents
     assert_raises Ai::Quota::UsageExceedsQuotaError do
-      @quota.ensure_under_limit
+      @quota.ensure_not_depleted
     end
 
     travel 10.days
-    @quota.ensure_under_limit
-  end
-
-  test "reset" do
-    @quota.used = "$15"
-    @quota.reset_at = 3.days.from_now
-
-    @quota.reset
-
-    assert_equal Ai::Quota::Money.wrap("$0"), @quota.used
-    assert_in_delta 7.days.from_now, @quota.reset_at, 1.minute
-
-    @quota.reset_at = 10.minutes.from_now
-    assert_not @quota.due_for_reset?
-
-    @quota.reset_at = 10.minutes.ago
-    assert @quota.due_for_reset?
-
-    @quota.reset_at = 10.minutes.from_now
-    @quota.used = "$15"
-    @quota.reset_if_due
-    assert_equal Ai::Quota::Money.wrap("$15"), @quota.used
-    assert_in_delta 10.minutes.from_now, @quota.reset_at, 1.minute
-
-    @quota.reset_at = 10.minutes.ago
-    @quota.used = "$15"
-    @quota.reset_if_due
-    assert_equal Ai::Quota::Money.wrap("$0"), @quota.used
-    assert_in_delta 7.days.from_now, @quota.reset_at, 1.minute
+    @quota.ensure_not_depleted
   end
 end