Download audio from a YouTube video

youtubemp3Downloader.ts

import axios from "axios";

interface AudioQualities {
    "320kbs": string;
    "256kbs": string;
    "192kbs": string;
    "128kbs": string;

}
interface Format {
    size: string;
    f: string;
    q: string;
    k: string;
}

interface Mp3 {
    "auto": Format;
    "320": Format;
    "256": Format;
    "192": Format;
    "128": Format;
    "96": Format;
    "64": Format;
}

interface Links {
    mp3: Mp3;
}

interface _9CloudResponse {
    data: {
        status: string;
        mess: string;
        p: string;
        vid: string;
        title: string;
        t: number;
        a: string;
        links: Links;
    };
}

export interface DownloadResponse {
    data: {
        status: string;
        mess: string;
        c_status: string;
        vid: string;
        title: string;
        ftype: string;
        fquality: string;
        dlink: string;
    }
}

function downloadYTVideo(ytLink: string, quality: string = "128kbs") {

    let videoID: string = "";
    const URLEncodedLink: string = encodeURI(ytLink);
    const data: string = `query=${URLEncodedLink}&vt=mp3`;

    const config: object = {
        method: "post",
        url: "https://9convert.com/api/ajaxSearch/index",
        data: data,
    };

    axios(config)
        .then(function (response: _9CloudResponse) {
            const qualities: AudioQualities | any = {
                "320kbs": response.data.links.mp3["320"].k,
                "256kbs": response.data.links.mp3["256"].k,
                "192kbs": response.data.links.mp3["192"].k,
                "128kbs": response.data.links.mp3["128"].k,
            };
            videoID = response.data.vid;
            getDownloadLink(videoID, qualities[quality]);
        })
        .catch(function (error: string) {
            console.log(error);
        });
}

function getDownloadLink(videoID: string, _9ConvertID: string) {
    let data = `vid=${videoID}&k=0%2${_9ConvertID}%3D`;
    data = data.replace("0+", "B").replace("=%", "%");
    console.log(data);
    const config: object = {
        method: "post",
        url: "https://9convert.com/api/ajaxConvert/convert",
        data: data,
    };

    axios(config)
        .then(function (response: DownloadResponse) {
            console.log(response.data);
        })
        .catch(function (error: string) {
            console.log(error);
        });
}

downloadYTVideo("https://www.youtube.com/watch?v=AtQKdlPeV0A", "256kbs");