Server compatibility

Better SSE works with any runtime that runs JavaScript (ES2020+) and supports the following APIs:

• Request, Response and AbortController from the Fetch API
• randomUUID from the Web Crypto API
• EventEmitter from node:events
• setImmediate from node:timers
• IncomingMessage and ServerResponse from node:http
  • Or at least stubs their imports to undefined if you are instead using the Fetch API
• Http2ServerRequest and Http2ServerResponse from node:http2
  • Or at least stubs their imports to undefined if you are instead using the Fetch API
• Readable from node:stream
  • Or at least stubs its import to undefined if you are instead using web streams
• ReadableStream, WritableStream and TransformStream from the Web Streams API
  • Only when using the Fetch API

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For Node users, version 20 is the minimum officially supported version.

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When using the Fetch API, the provided Request and optional Response object must be instances of globalThis.Request and globalThis.Response, respectively. Providing a ponyfilled implementation will cause an error to be thrown unless you also assign it to globalThis:

import {
    Request as PonyfilledRequest,
    Response as PonyfilledResponse
} from "fetch-ponyfill"

globalThis.Request = PonyfilledRequest
globalThis.Response = PonyfilledResponse