Track API Usage Per Customer with LogIt

// middleware/api-usage.ts (Express/Node.js)
import { logit } from "@/lib/logit";

export async function apiUsageMiddleware(req: Request, res: Response, next: NextFunction) {
  const start = Date.now();
  const customerId = req.user?.organizationId ?? "anonymous";
  const plan = req.user?.plan ?? "unknown";

  res.on("finish", async () => {
    const duration = Date.now() - start;

    await logit.now("api-usage", {
      event: "API request",
      description: `${req.method} ${req.path} — ${res.statusCode} (${duration}ms)`,
      icon: "⚡",
      notify: false,
      tags: {
        customerId,
        plan,
        method: req.method,
        status: res.statusCode.toString(),
        endpoint: req.path,
      },
      metadata: {
        customerId,
        duration,
        statusCode: res.statusCode,
        path: req.path,
        method: req.method,
      },
    }).catch(console.error);  // fire-and-forget
  });

  next();
}

// For expensive operations (AI calls, large exports), log separately
await logit.now("api-usage-premium", {
  event: "Premium API call",
  description: `Customer ${customerId} — /api/ai/generate (${tokens} tokens)`,
  icon: "🤖",
  notify: false,
  tags: { customerId, plan, operation: "ai-generate" },
  metadata: { customerId, tokens, model, duration },
});