Networking

fetch, WebSocket, EventSource and XMLHttpRequest, and where they differ from a browser.

fetch, XMLHttpRequest, WebSocket and EventSource are globals. No import, no permission. They follow the specs, so MDN is the reference.

URLs must be absolute. A relative URL like "/api/status" fails.

const res = await fetch("https://httpbin.org/json", { signal: AbortSignal.timeout(5000) });
if (res.ok) console.log(await res.json());

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Differences from a browser

• No CORS and no cookie jar. Any header (User-Agent, Cookie, Origin, …) goes out as you set it.
• redirect: "manual" returns the real 3xx response, so you can read Location.
• The system proxy is ignored.
• Certificates are always checked; there’s no way to skip it.
• Network and certificate failures reject with a TypeError whose cause.code is "ENETWORK" or "ECERT". A non-2xx status resolves normally, check res.ok.
• XMLHttpRequest can’t be synchronous (open(method, url, false) throws), and responseXML is always null.

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WebSocket

const ws = new WebSocket("wss://ws.postman-echo.com/raw");
ws.binaryType = "arraybuffer";
ws.onopen = () => ws.send("hello");
ws.onmessage = (e) => console.log(e.data);
ws.onclose = (e) => console.log("closed", e.code, e.wasClean);

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Example

Post the map to a server when it changes, with a timeout.

import game from "@native/game";

const ENDPOINT = "https://example.com/api/map";
let lastMap: string | null = null;

async function report(map: string): Promise<void> {
    try {
        const res = await fetch(ENDPOINT, {
            method: "POST",
            headers: { "content-type": "application/json" },
            body: JSON.stringify({ map, player: script.name }),
            signal: AbortSignal.timeout(5000),
        });
        if (!res.ok) console.warn("server said", res.status);
    } catch (e) {
        console.warn("report failed:", (e as Error).message);
    }
}

on("tick", () => {
    const map = game.shortMapName;
    if (!map || map === lastMap) return;
    lastMap = map;
    void report(map);
});