A small js to add Steam games to you wishlist, for example if you want to merge multiple wishlists from different steam account or move to another account

SteamAddIDsToWishlist.js

// You need to paste this code in your browser's console while on steam store, on chrome you need to allow pasting before.

// List AppIDs here
// I got it by exporting via argumented steam browser extension and using export text with "%appid%,"
const appIdsToAdd = [1, 2, 3, 4];

(async function () {
    "use strict";
    
    // Safety check to ensure you are logged in and on the right page
    if (typeof g_sessionID === "undefined") {
        console.error("Session ID not found! Make sure you are logged in and on store.steampowered.com");
        return;
    }

    const sleep = ms => new Promise(r => setTimeout(r, ms));
    
    let count = 0;
    for (const appid of appIdsToAdd) {
        // Prepare the data to send to the server
        const data = new URLSearchParams();
        data.set("sessionid", g_sessionID);
        data.set("appid", appid);
        
        try {
            // Talk directly to Steam's hidden Wishlist API
            const response = await fetch("https://store.steampowered.com/api/addtowishlist", {
                method: "POST",
                body: data,
                headers: {
                    'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'
                }
            });
            
            const result = await response.json();
            
            if (result.success === true || result.success === 1) {
                count++;
                console.log(`[Success] Added AppID: ${appid} (${count}/${appIdsToAdd.length})`);
            } else {
                console.error(`[Failed] Could not add AppID: ${appid}`, result);
            }
        } catch (err) {
            console.error(`[Error] Connection issue on AppID: ${appid}`, err);
        }
        
        // 3-second delay against bot detection
        await sleep(3000);
    }
    console.log("Finished importing wishlist! You can now refresh the page.");
})();