Simple discord.com script to leave all group DMs after some inactivity time

script.js

{
    // personal discord token (can be found in cookies)
    const TOKEN = ''
    // inactivity threshold in days
    const LEAVE_THRESHOLD = 30

    const wait = (ms) => new Promise(resolve => setTimeout(resolve, ms))
    
    const getChannels = async () => {
        const res = await fetch('https://discord.com/api/v9/users/@me/channels', {
            headers: {
                Authorization: TOKEN,
            }
        })
        return res.json()
    }

    const getLastMessageTimestamp = async (id) => {
        const res = await fetch(`https://discord.com/api/v9/channels/${id}/messages`, {
            headers: {
                Authorization: TOKEN,
            }
        })
        
        // filter out all system messages
        const messages = (await res.json()).filter(m => m.type === 0)

        if (!messages.length) return 0

        return (new Date(messages[0].timestamp)).getTime()
    }

    const leave = async (id) => {
        const res = await fetch(`https://discord.com/api/v9/channels/${id}`, {
            method: 'DELETE',
            headers: {
                Authorization: TOKEN,
            }
        })
        return res.json()
    }

    const channels = await getChannels()
    const groups = channels.filter(ch => ch.type === 3)

    const deleteUpTo = (new Date).getTime() - (LEAVE_THRESHOLD * 86400 * 1e3)

    for (const g of groups) {
        const ts = await getLastMessageTimestamp(g.id)

        if (ts < deleteUpTo) {
            console.log(`leaving ${g.id}...`)
            await leave(g.id)
        }

        await wait(100)
    }
}