Mô hình tính phí của Cursor

import DodoPayments from 'dodopayments';

/**
 * Determines the credit cost for a given request type and model.
 * This logic lives in your application and can be updated without
 * changing your billing configuration.
 */
function getCreditCost(requestType: string, model: string): number {
  const costs: Record<string, Record<string, number>> = {
    'tab_completion': { 'default': 0 },
    'chat': { 'gpt-4o-mini': 1, 'gpt-4o': 1, 'claude-sonnet': 1 },
    'composer': { 'gpt-4o-mini': 2, 'gpt-4o': 5, 'claude-sonnet': 5 },
    'agent': { 'gpt-4o': 10, 'claude-sonnet': 10, 'o1': 25 }
  };
  
  // Default to 1 credit if the combination isn't found
  return costs[requestType]?.[model] ?? 1;
}

/**
 * Ingests usage events into Dodo Payments.
 * The meter sums credit_cost, so one event carries the full weight of the request.
 */
async function trackRequest(customerId: string, requestType: string, model: string) {
  const creditCost = getCreditCost(requestType, model);
  
  // Tab completions are free, so we don't need to track them for billing
  if (creditCost === 0) return;
  
  const client = new DodoPayments({
    bearerToken: process.env.DODO_PAYMENTS_API_KEY,
  });
  
  await client.usageEvents.ingest({
    events: [{
      event_id: `req_${Date.now()}_${Math.random().toString(36).slice(2)}`,
      customer_id: customerId,
      event_name: 'ai.request',
      timestamp: new Date().toISOString(),
      metadata: {
        request_type: requestType,
        model: model,
        credit_cost: creditCost
      }
    }]
  });
}

import DodoPayments from 'dodopayments';
import express from 'express';

const app = express();
app.use(express.raw({ type: 'application/json' }));

const client = new DodoPayments({
  bearerToken: process.env.DODO_PAYMENTS_API_KEY,
  webhookKey: process.env.DODO_PAYMENTS_WEBHOOK_KEY,
});

// updateUserTier, getUserTier, and notifyUser are your application's own functions.
app.post('/webhooks/dodo', async (req, res) => {
  try {
    const event = client.webhooks.unwrap(req.body.toString(), {
      headers: {
        'webhook-id': req.headers['webhook-id'] as string,
        'webhook-signature': req.headers['webhook-signature'] as string,
        'webhook-timestamp': req.headers['webhook-timestamp'] as string,
      },
    });
    
    if (event.type === 'credit.balance_low') {
      const customerId = event.data.customer_id;
      await updateUserTier(customerId, 'slow');
      await notifyUser(customerId, 'You have used most of your premium requests. Switching to standard models.');
    }
    
    res.json({ received: true });
  } catch (error) {
    res.status(401).json({ error: 'Invalid signature' });
  }
});

/**
 * Routes a request based on the user's current tier.
 * This function is called before every AI request to determine the model and queue.
 */
async function routeRequest(customerId: string, requestType: string) {
  const tier = await getUserTier(customerId);
  
  if (tier === 'slow') {
    // Route to a cheaper model and a lower priority queue
    // This saves costs while keeping the user active in the product
    return { model: 'gpt-4o-mini', queue: 'standard' };
  }
  
  // Premium routing for users with remaining credits
  // This provides the best possible performance and model quality
  return { model: 'claude-sonnet', queue: 'priority' };
}

import DodoPayments from 'dodopayments';

const client = new DodoPayments({
  bearerToken: process.env.DODO_PAYMENTS_API_KEY,
});

/**
 * Creates a checkout session for a new subscription.
 * This is typically called when a user clicks an "Upgrade" button.
 */
const session = await client.checkoutSessions.create({
  product_cart: [
    { product_id: 'pdt_cursor_pro', quantity: 1 }
  ],
  customer: { email: 'developer@example.com' },
  return_url: 'https://yourapp.com/dashboard'
});