Runtime APIs

To provide you with the best experience possible, we strive to adhere to the WinterCG requirements.

Request Handler

To serve a dynamic request, you either need to export a function of your choice or listen to fetch events.

export function handler(event: Request) {
  return new Response('Hallo Welt!');
}

addEventListener('fetch', (event) => {
  event.respondWith(new Response('Hello World!'));
});

Global Objects

Next to the standard built-in objects, we implement the following APIs.

`AbortController`

`AbortSignal`

`AsyncLocalStorage`

`atob`

`Blob`

`btoa`

`Buffer`

`ByteLengthQueuingStrategy`

`clearInterval`

`clearTimeout`

`CompressionStream`

`console`

console.log
console.trace
console.info
console.debug
console.error
console.warn

`CountQueuingStrategy`

`crypto.getRandomValues`

`crypto.randomUUID`

`crypto.subtle`

Please see the SubtleCrypto interface.

`CryptoKey`

`CryptoKeyPair`

`CustomEvent`

`Date` (built-in)

`DecompressionStream`

`DOMException`

`EdgeRuntime`

Similar to Vercel, we expose the EdgeRuntime property. You can use it to check if your code is running on an Edge runtime.

`Event`

`EventTarget`

`fetch`

`File`

`FileReader`

`FormData`

`Headers`

`navigator`

`performance`

`queueMicrotask`

`ReadableByteStreamController`

`ReadableStream`

`ReadableStreamBYOBReader`

`ReadableStreamBYOBRequest`

`ReadableStreamDefaultController`

`ReadableStreamDefaultReader`

`Request`

`Response`

`setInterval`

`setTimeout`

`structuredClone`

`SubtleCrypto`

	sign	verify	encrypt	decrypt	digest	deriveBits	deriveKey	wrapKey	unwrapKey
RSASSA-PKCS1-v1_5	✓	✓
RSA-PSS	✓	✓
ECDSA	✓	✓
HMAC	✓	✓
RSA-OAEP			✓	✓				✓	✓
AES-CTR			✓	✓				✓	✓
AES-CBC			✓	✓				✓	✓
AES-GCM			✓	✓				✓	✓
SHA-1					✓
SHA-256					✓
SHA-384					✓
SHA-512					✓
ECDH						✓	✓
HKDF						✓	✓
PBKDF2						✓	✓
AES-KW								✓	✓