The following APIs are the same as the Web APIS you already know. Additionally, we follow the WinterCG conventions.
Handler
The only required code to make your Function runnable is to export a handler function, that accepts a Request and returns a Response (or a promise returning a Response):
export function handler(request: Request): Response {
return new Response('Hello World!');
}Starting from this simple code, you can do whatever you whish, using the Web APIs you already know.
Global objects
console
Similar to the the standard console object on the browser and on Node.js, expect that it only supports the following methods:
loginfodebugwarnerror
You can log multiple objects, and use string substitution. See the documentation on MDN.
process
The only usage of process is to get environment variables via process.env.
Example:
export function handler(request: Request): Response {
return new Response(`My secret is: ${process.env.SECRET}`);
}crypto
The standard crypto object.
crypto.randomUUID()
The standard randomUUID() method. See the documentation on MDN.
crypto.getRandomValues()
The standard getRandomValues() method. See the documentation on MDN.
crypto.subtle
The standard CryptoSubtle object. See the documentation on MDN.
The following table summarizes the supported algorithms on each method:
sign(), verify() | encrypt(), decrypt() | digest() | deriveBits(), deriveKey() | wrapKey(), unwrapKey() | |
|---|---|---|---|---|---|
| HMAC | ✅ | ||||
| SHA-256 | ✅ | ||||
| SHA-384 | ✅ | ||||
| SHA-512 | ✅ | ||||
| AES-GCM | ✅ | ✅ |
TextEncoder
The standard TextEncoder object. See the documentation on MDN.
TextDecoder
The standard TextDecoder object. See the documentation on MDN.
AbortController
The standard AbortController object. See the documentation on MDN.
AbortSignal
The standard AbortSignal object. See the documentation on MDN.
Fetch
fetch() method? Jump to fetch().Request
The standard Request object. See the documentation on MDN.
Response
The standard Response object. See the documentation on MDN.
Streaming:
You can pass a ReadableStream object as the body of a Response to stream the response as more data becomes available. Often, you won't need to implement the logic yourself as it is implemented by the frameworks and libraries you use.
URL
The standard URL object. See the documentation on MDN.
URLSearchParams
The standard URLSearchParams object. See the documentation on MDN.
Headers
The standard Headers object. See the documentation on MDN.
Streams
ReadableStream
The standard ReadableStream object. See the documentation on MDN.
ReadableStreamDefaultReader
The standard ReadableStreamDefaultReader object. See the documentation on MDN.
WritableStream
The standard WritableStream object. See the documentation on MDN.
WritableStreamDefaultWriter
The standard WritableStreamDefaultWriter object. See the documentation on MDN.
TransformStream
The standard TransformStream object. See the documentation on MDN.
Global methods
fetch()
The standard fetch method. See the documentation on MDN.
atob()
The standard atob method. See the documentation on MDN.
btoa()
The standard btoa method. See the documentation on MDN.