Remove cost calculations (#718)

Author: mattlindsey

app/models/conversation.rb

@@ -65,9 +65,6 @@ def self.grouped_by_increasing_time_interval_for_user(user, query = nil)
       .delete_if { |_, v| v.empty? }
   end
 
-  def total_cost
-    input_token_total_cost + output_token_total_cost
-  end
 
   def generate_shareable_url(request)
     ensure_share_token!

app/models/language_model/export.rb

@@ -9,8 +9,6 @@ module LanguageModel::Export
     supports_images
     supports_tools
     supports_system_message
-    input_token_cost_cents
-    output_token_cost_cents
   ]
 
   DEFAULT_MODEL_FILE = "models.yml"

app/models/message.rb

@@ -25,8 +25,6 @@ class Message < ApplicationRecord
   after_create :start_assistant_reply, if: :user?
   after_create :set_last_assistant_message, if: :assistant?
   after_save :update_assistant_on_conversation, if: -> { assistant.present? && conversation.present? }
-  before_save :update_input_token_cost, if: :input_token_count_changed?
-  before_save :update_output_token_cost, if: :output_token_count_changed?
 
   scope :ordered, -> { latest_version_for_conversation }
 
@@ -78,13 +76,5 @@ def update_assistant_on_conversation
     conversation.update!(assistant:)
   end
 
-  def update_input_token_cost
-    return if assistant.language_model.input_token_cost_cents.blank?
-    self.input_token_cost = assistant.language_model.input_token_cost_cents * input_token_count
-  end
 
-  def update_output_token_cost
-    return if assistant.language_model.output_token_cost_cents.blank?
-    self.output_token_cost = assistant.language_model.output_token_cost_cents * output_token_count
-  end
 end

app/models/message/billable.rb

@@ -4,7 +4,5 @@ module Message::Billable
     rollup_cache :input_token_total_count, sum: :input_token_count, belongs_to: :conversation
     rollup_cache :output_token_total_count, sum: :output_token_count, belongs_to: :conversation
 
-    rollup_cache :input_token_total_cost, sum: :input_token_cost, belongs_to: :conversation
-    rollup_cache :output_token_total_cost, sum: :output_token_cost, belongs_to: :conversation
   end
 end

app/views/conversations/_conversation.html.erb

@@ -79,32 +79,20 @@
           </li>
           <footer class="py-3 px-4 mt-1 border-t-2 border-gray-100 dark:border-gray-600 gap-2 flex flex-col">
             <table class="w-full text-left">
-              <tr>
-                <td class="pb-2 whitespace-nowrap"><%= t('app.conversations.cost_summary.conversation_approx') %></td>
-                <td class="pb-2"><%= to_dollars(conversation.total_cost)%></td>
-              </tr>
               <tr>
                 <td class="pb-2 font-bold" colspan="2"><%= t('app.conversations.cost_summary.input') %></td>
               </tr>
               <tr>
                 <td class="pb-2"><%= t('app.conversations.cost_summary.tokens') %></td>
                 <td class="pb-2"><%= conversation.input_token_total_count %></td>
               </tr>
-              <tr>
-                <td class="pb-2"><%= t('app.conversations.cost_summary.cost') %></td>
-                <td class="pb-2"><%= to_dollars(conversation.input_token_total_cost, precision: 5) %></td>
-              </tr>
               <tr>
                 <td class="pb-2 font-bold" colspan="2"><%= t('app.conversations.cost_summary.output') %></td>
               </tr>
               <tr>
                 <td><%= t('app.conversations.cost_summary.tokens') %></td>
                 <td><%= conversation.output_token_total_count %></td>
               </tr>
-              <tr>
-                <td><%= t('app.conversations.cost_summary.cost') %></td>
-                <td><%= to_dollars(conversation.output_token_total_cost, precision: 5) %></td>
-              </tr>
             </table>
           </footer>
         </menu>

db/migrate/20250930102932_remove_token_cost_columns_from_language_models.rb

@@ -0,0 +1,6 @@
+class RemoveTokenCostColumnsFromLanguageModels < ActiveRecord::Migration[8.0]
+  def change
+    remove_column :language_models, :input_token_cost_cents, :decimal
+    remove_column :language_models, :output_token_cost_cents, :decimal
+  end
+end

db/migrate/20250930104155_remove_cost_columns_from_conversations.rb

@@ -0,0 +1,6 @@
+class RemoveCostColumnsFromConversations < ActiveRecord::Migration[8.0]
+  def change
+    remove_column :conversations, :input_token_total_cost, :decimal
+    remove_column :conversations, :output_token_total_cost, :decimal
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_09_14_143833) do
+ActiveRecord::Schema[8.0].define(version: 2025_09_30_104155) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_catalog.plpgsql"
 
@@ -118,8 +118,6 @@
     t.datetime "updated_at", null: false
     t.bigint "last_assistant_message_id"
     t.text "external_id", comment: "The Backend AI system (e.g OpenAI) Thread Id"
-    t.decimal "input_token_total_cost", precision: 30, scale: 15, default: "0.0", null: false
-    t.decimal "output_token_total_cost", precision: 30, scale: 15, default: "0.0", null: false
     t.integer "input_token_total_count", default: 0, null: false
     t.integer "output_token_total_count", default: 0, null: false
     t.string "share_token"
@@ -174,8 +172,6 @@
     t.bigint "user_id", null: false
     t.bigint "api_service_id"
     t.boolean "supports_tools", default: false
-    t.decimal "input_token_cost_cents", precision: 30, scale: 15
-    t.decimal "output_token_cost_cents", precision: 30, scale: 15
     t.boolean "best", default: false
     t.boolean "supports_system_message", default: false
     t.boolean "supports_pdf", default: false, null: false