Handling credit exhaustion

async function ensureCredits(needed: number) {
  const credits = await reader.getCredits();
  if (credits.balance < needed) {
    throw new Error(
      `Insufficient credits: need ${needed}, have ${credits.balance}. ` +
        `Resets at ${credits.resetAt}.`,
    );
  }
}

await ensureCredits(estimateBatchCost(urls));
const result = await reader.read({ urls });

import { InsufficientCreditsError } from "@vakra-dev/reader-js";

try {
  await reader.read({ url });
} catch (err) {
  if (err instanceof InsufficientCreditsError) {
    console.error(`Need ${err.required}, have ${err.available}`);
    console.error(`Resets at ${err.resetAt}`);
    await pauseWorker();
    await alertOps("reader-credits-exhausted", {
      available: err.available,
      resetAt: err.resetAt,
    });
    return;
  }
  throw err;
}

await reader.request("POST", "/v1/webhooks", {
  url: "https://your-app.example.com/hooks/reader",
  name: "Credit alerts",
  events: ["credit.low"],
  secret: process.env.READER_WEBHOOK_SECRET,
});

const DAILY_BUDGET = 1000;
let dailySpend = 0;

async function scrapeWithBudget(url: string) {
  if (dailySpend >= DAILY_BUDGET) {
    throw new Error("Daily budget exhausted");
  }

  const result = await reader.read({ url });
  // The actual cost is 1 or 3 depending on the resolved mode
  const cost = result.data.metadata?.proxyMode === "premium" ? 3 : 1;
  dailySpend += cost;

  return result;
}