diff --git a/src/api/controller/stats.js b/src/api/controller/stats.js
new file mode 100644
index 0000000..46064b8
--- /dev/null
+++ b/src/api/controller/stats.js
@@ -0,0 +1,149 @@
+const Prompt = require('../../models/Prompt');
+const { Op } = require('sequelize');
+const sequelize = require('../../config/database');
+
+/**
+ * Calculate expense summaries per model with time granularity
+ * @param {Object} [options] - Query options
+ * @param {string} [options.startDate] - Start date for the summary (ISO format)
+ * @param {string} [options.endDate] - End date for the summary (ISO format)
+ * @param {string} [options.granularity='monthly'] - Time granularity ('daily', 'monthly', 'yearly')
+ * @returns {Promise<Object>} Summary of expenses per model and time period
+ */
+async function getModelExpenses({ startDate, endDate, granularity = 'monthly' } = {}) {
+  const where = {};
+  
+  // Add date range if provided
+  if (startDate || endDate) {
+    where.created_at = {};
+    if (startDate) where.created_at[Op.gte] = new Date(startDate);
+    if (endDate) where.created_at[Op.lte] = new Date(endDate);
+  }
+
+  // Define time period format based on granularity
+  const timeFormat = {
+    daily: '%Y-%m-%d',
+    monthly: '%Y-%m',
+    yearly: '%Y'
+  }[granularity] || '%Y-%m'; // Default to monthly if invalid granularity
+
+  // Get all prompts within the date range
+  const prompts = await Prompt.findAll({
+    where,
+    attributes: [
+      'model',
+      [sequelize.fn('date_trunc', granularity, sequelize.col('created_at')), 'time_period'],
+      [sequelize.fn('COUNT', sequelize.col('id')), 'total_requests'],
+      [sequelize.fn('SUM', sequelize.col('prompt_tokens')), 'total_prompt_tokens'],
+      [sequelize.fn('SUM', sequelize.col('response_tokens')), 'total_response_tokens'],
+      [sequelize.fn('SUM', sequelize.col('total_tokens')), 'total_tokens'],
+      [sequelize.fn('SUM', sequelize.col('your_cost_usd')), 'total_cost'],
+      [sequelize.fn('AVG', sequelize.col('your_cost_usd')), 'avg_cost_per_request'],
+      [sequelize.fn('SUM', sequelize.col('cost_gpt4_usd')), 'total_gpt4_cost'],
+      [sequelize.fn('SUM', sequelize.col('cost_claude_usd')), 'total_claude_cost'],
+      [sequelize.fn('SUM', sequelize.col('cost_gemini_usd')), 'total_gemini_cost'],
+      [sequelize.fn('SUM', sequelize.col('savings_vs_gpt4')), 'total_savings_vs_gpt4'],
+      [sequelize.fn('SUM', sequelize.col('savings_vs_claude')), 'total_savings_vs_claude'],
+      [sequelize.fn('SUM', sequelize.col('savings_vs_gemini')), 'total_savings_vs_gemini']
+    ],
+    group: ['model', 'time_period'],
+    order: [
+      ['time_period', 'DESC'],
+      [sequelize.fn('SUM', sequelize.col('your_cost_usd')), 'DESC']
+    ]
+  });
+
+  // Group results by time period
+  const groupedByTime = prompts.reduce((acc, model) => {
+    const timePeriod = model.getDataValue('time_period');
+    const modelData = {
+      model: model.getDataValue('model'),
+      total_requests: parseInt(model.getDataValue('total_requests')),
+      total_prompt_tokens: parseInt(model.getDataValue('total_prompt_tokens') || 0),
+      total_response_tokens: parseInt(model.getDataValue('total_response_tokens') || 0),
+      total_tokens: parseInt(model.getDataValue('total_tokens') || 0),
+      total_cost: parseFloat(model.getDataValue('total_cost') || 0).toFixed(6),
+      avg_cost_per_request: parseFloat(model.getDataValue('avg_cost_per_request') || 0).toFixed(6),
+      total_gpt4_cost: parseFloat(model.getDataValue('total_gpt4_cost') || 0).toFixed(6),
+      total_claude_cost: parseFloat(model.getDataValue('total_claude_cost') || 0).toFixed(6),
+      total_gemini_cost: parseFloat(model.getDataValue('total_gemini_cost') || 0).toFixed(6),
+      total_savings_vs_gpt4: parseFloat(model.getDataValue('total_savings_vs_gpt4') || 0).toFixed(6),
+      total_savings_vs_claude: parseFloat(model.getDataValue('total_savings_vs_claude') || 0).toFixed(6),
+      total_savings_vs_gemini: parseFloat(model.getDataValue('total_savings_vs_gemini') || 0).toFixed(6)
+    };
+
+    if (!acc[timePeriod]) {
+      acc[timePeriod] = {
+        models: [],
+        totals: {
+          total_requests: 0,
+          total_prompt_tokens: 0,
+          total_response_tokens: 0,
+          total_tokens: 0,
+          total_cost: 0,
+          total_gpt4_cost: 0,
+          total_claude_cost: 0,
+          total_gemini_cost: 0,
+          total_savings_vs_gpt4: 0,
+          total_savings_vs_claude: 0,
+          total_savings_vs_gemini: 0
+        }
+      };
+    }
+
+    acc[timePeriod].models.push(modelData);
+    
+    // Update period totals
+    const totals = acc[timePeriod].totals;
+    totals.total_requests += modelData.total_requests;
+    totals.total_prompt_tokens += modelData.total_prompt_tokens;
+    totals.total_response_tokens += modelData.total_response_tokens;
+    totals.total_tokens += modelData.total_tokens;
+    totals.total_cost += parseFloat(modelData.total_cost);
+    totals.total_gpt4_cost += parseFloat(modelData.total_gpt4_cost);
+    totals.total_claude_cost += parseFloat(modelData.total_claude_cost);
+    totals.total_gemini_cost += parseFloat(modelData.total_gemini_cost);
+    totals.total_savings_vs_gpt4 += parseFloat(modelData.total_savings_vs_gpt4);
+    totals.total_savings_vs_claude += parseFloat(modelData.total_savings_vs_claude);
+    totals.total_savings_vs_gemini += parseFloat(modelData.total_savings_vs_gemini);
+
+    return acc;
+  }, {});
+
+  // Format the response
+  const periods = Object.entries(groupedByTime).map(([timePeriod, data]) => {
+    const totals = data.totals;
+    totals.avg_cost_per_request = totals.total_requests > 0 
+      ? (totals.total_cost / totals.total_requests).toFixed(6)
+      : '0.000000';
+
+    // Format all totals to 6 decimal places
+    Object.keys(totals).forEach(key => {
+      if (typeof totals[key] === 'number') {
+        totals[key] = totals[key].toFixed(6);
+      }
+    });
+
+    return {
+      time_period: timePeriod,
+      models: data.models,
+      totals
+    };
+  });
+
+  // Sort periods by time (newest first)
+  periods.sort((a, b) => new Date(b.time_period) - new Date(a.time_period));
+
+  return {
+    granularity,
+    periods,
+    date_range: {
+      start: startDate || null,
+      end: endDate || null
+    }
+  };
+}
+
+module.exports = {
+  getModelExpenses
+}; 
\ No newline at end of file
diff --git a/src/api/network/stats.js b/src/api/network/stats.js
new file mode 100644
index 0000000..bc6f601
--- /dev/null
+++ b/src/api/network/stats.js
@@ -0,0 +1,70 @@
+const { getModelExpenses } = require('../controller/stats');
+
+/**
+ * Get expense summaries per model
+ * @param {Object} req - Express request object
+ * @param {Object} res - Express response object
+ */
+async function getExpenses(req, res) {
+  try {
+    const { start_date, end_date, granularity = 'monthly' } = req.query;
+    
+    // Validate granularity
+    if (!['daily', 'monthly', 'yearly'].includes(granularity)) {
+      return res.status(400).json({
+        success: false,
+        error: 'Invalid granularity. Must be one of: daily, monthly, yearly'
+      });
+    }
+    
+    // Validate date formats if provided
+    if (start_date && !isValidDate(start_date)) {
+      return res.status(400).json({
+        success: false,
+        error: 'Invalid start_date format. Use ISO 8601 format (YYYY-MM-DD)'
+      });
+    }
+    
+    if (end_date && !isValidDate(end_date)) {
+      return res.status(400).json({
+        success: false,
+        error: 'Invalid end_date format. Use ISO 8601 format (YYYY-MM-DD)'
+      });
+    }
+
+    const summary = await getModelExpenses({
+      startDate: start_date,
+      endDate: end_date,
+      granularity
+    });
+
+    res.json({
+      success: true,
+      data: summary
+    });
+  } catch (error) {
+    console.error('Error fetching expense summary:', error);
+    res.status(500).json({
+      success: false,
+      error: 'Failed to fetch expense summary',
+      message: error.message
+    });
+  }
+}
+
+/**
+ * Validate date string format (YYYY-MM-DD)
+ * @param {string} dateString - The date string to validate
+ * @returns {boolean} Whether the date string is valid
+ */
+function isValidDate(dateString) {
+  const regex = /^\d{4}-\d{2}-\d{2}$/;
+  if (!regex.test(dateString)) return false;
+  
+  const date = new Date(dateString);
+  return date instanceof Date && !isNaN(date);
+}
+
+module.exports = {
+  getExpenses
+}; 
\ No newline at end of file
diff --git a/src/app.js b/src/app.js
new file mode 100644
index 0000000..94b7aae
--- /dev/null
+++ b/src/app.js
@@ -0,0 +1,8 @@
+const generateRoutes = require('./routes/generate');
+const logsRoutes = require('./routes/logs');
+const statsRoutes = require('./routes/stats');
+
+// API routes
+app.use('/api/generate', generateRoutes);
+app.use('/api/logs', logsRoutes);
+app.use('/api/stats', statsRoutes); 
\ No newline at end of file
diff --git a/src/routes/stats.js b/src/routes/stats.js
new file mode 100644
index 0000000..7fd45a7
--- /dev/null
+++ b/src/routes/stats.js
@@ -0,0 +1,16 @@
+const express = require('express');
+const router = express.Router();
+const { validateApiKey } = require('../middleware/auth');
+const { getExpenses } = require('../api/network/stats');
+
+// Apply API key validation to all routes
+router.use(validateApiKey);
+
+// Get expense summaries per model
+// Optional query parameters:
+// - start_date: Start date in YYYY-MM-DD format
+// - end_date: End date in YYYY-MM-DD format
+// - granularity: Time granularity ('daily', 'monthly', 'yearly'). Defaults to 'monthly'
+router.get('/expenses', getExpenses);
+
+module.exports = router; 
\ No newline at end of file