Edge runtimes

better-payment has no runtime dependencies and uses only web-standard APIs: fetch, WebCrypto (crypto.subtle), TextEncoder and atob/btoa. The same package runs on:

• Node.js 20+
• Vercel Edge Functions and Next.js routes with runtime = 'edge'
• Cloudflare Workers
• Deno and Deno Deploy
• Bun

Every release is tested in the Vercel Edge Runtime VM. That VM has no Buffer, process or require. The test signs requests and verifies callbacks for all four providers there, and compares the results with values computed in Node.js.

Next.js (edge)

The Next.js route handler works unchanged. Only switch the runtime:

// app/api/pay/[...path]/route.ts
export const runtime = 'edge'; // or 'nodejs'

Cloudflare Workers

import { betterPayment, iyzico, toFetchHandler } from 'better-payment';

interface Env {
  IYZICO_API_KEY: string;
  IYZICO_SECRET_KEY: string;
}

export default {
  fetch(request: Request, env: Env): Promise<Response> {
    const payment = betterPayment({
      mode: 'sandbox',
      providers: {
        iyzico: iyzico({ apiKey: env.IYZICO_API_KEY, secretKey: env.IYZICO_SECRET_KEY }),
      },
    });
    return toFetchHandler(payment)(request);
  },
};

Deno and Bun

import { betterPayment, toFetchHandler } from 'npm:better-payment';

const payment = betterPayment({ /* ... */ });

Deno.serve(toFetchHandler(payment));          // Deno
// Bun.serve({ fetch: toFetchHandler(payment) }); // Bun

toFetchHandler turns the handler into a (request: Request) => Promise<Response> function. Hono has its own adapter.

Idempotency on edge and serverless

The default idempotency store keeps duplicate-callback and Idempotency-Key records in memory. On edge and serverless platforms, every isolate or instance has its own memory, so it only deduplicates requests that reach the same isolate. Pass a shared store in production:

• Upstash Redis (HTTP-based, works on every edge runtime): SET key value EX ttl NX for setIfAbsent.
• Cloudflare: Durable Objects or D1 (INSERT ... ON CONFLICT DO NOTHING). Workers KV is eventually consistent and cannot implement the atomic setIfAbsent.

Custom fetch

Provider API calls use globalThis.fetch. Pass your own implementation, for example to route requests through a proxy or to stub them in tests:

betterPayment({
  fetch: (input, init) => fetch(input, { ...init, keepalive: true }),
  providers: { /* ... */ },
});