import requests
import time
import shutil

headers = {"Authorization": "api_key"}
file_list = ["/path/to/file.pdf"]
params = {
    "lang": "en",
    "convert_to": "pdf-docx",
    "ocr": False
}


def download_file(url, local_filename, api_url):
    url = f"{api_url}/{url.strip('/')}"

    with requests.get(url, stream=True) as r:
        with open(local_filename, "wb") as f:
            shutil.copyfileobj(r.raw, f)

    return local_filename


def convert_files(params, headers):
    r = requests.get(
        url="https://www.epub.to/apis/"
    )

    if r.status_code != 200:
        print("We couldn't get the API name")
        print(r.status_code)
        print(r.content)
        return None, None

    api_url = r.json().get("api")
    files = [eval(f'("files", open("{file}", "rb"))') for file in file_list]
    r = requests.post(
        url=f"{api_url}/v1/convert/",
        files=files,
        data=params,
        headers=headers
    )

    if r.status_code != 200:
        print(r.status_code)
        print(r.content)
        return None, None

    return r.json(), api_url


def get_results(params, api_url):
    if params.get("error"):
        print(params)
        return params.get("error")

    r = requests.post(
        url=f"{api_url}/v1/results/",
        data=params
    )
    data = r.json()
    finished = data.get("finished")

    if not finished:
        if int(data.get("queue_count")) > 0:
            print("queue: %s" % data.get("queue_count"))

        time.sleep(5)
        get_results(params, api_url)
        return

    for f in data.get("files"):
        print(f.get("url"))
        download_file(f.get("url"), f.get("filename"), api_url)

    return {"finished": "files downloaded"}


resp, api_url = convert_files(params, headers)
get_results(resp, api_url)

Request (Get API URL):
curl https://www.epub.to/apis/
Response:
{api: <api_url>}

Request (Upload files for conversion):
curl -F "lang=en" -F "convert_to=mp4-wav" -F "files=@testfiles/blah.pdf" -F "files=@testfiles/blah.pdf" -F "files=@testfiles/blah.pdf" -H "Authorization: <api_key>" <api_url>/v1/convert/
Response:
{uuid: <conversion_uuid>}


Request (Get download URLs):
curl -F "uuid=<conversion_uuid>" -H "Authorization: <api_key>" <api_url>/v1/results/
Response:
{"files": [{"download_url": <download_url>, "url": <url>, filename: <filename>}], "failed": [], "finished": true, "queue_count": 0, "errors": []}

<?php
ini_set("display_errors", 1);
ini_set("display_startup_errors", 1);
error_reporting(E_ERROR | E_PARSE);

$headers = array("Authorization: api_key");
$file_list = ["/path/to/file.pdf"];

function download_file($url, $filename, $api_url){
    $curl = curl_init();
    $url = $api_url.trim($url, "/");
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_SSLVERSION, 3);
    $data = curl_exec($curl);
    $error = curl_error($curl);
    curl_close ($curl);
    # Make sure destionation path exists
    $destination_path = "/path/to/file/";
    $destination_file = fopen($destination_path . $filename, "w+");
    fwrite($destination_file, $data);
    fclose($destination_file);
}

function convert_files($file_list, $headers, $convert_to) {
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, "https://www.epub.to/apis/");
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    $content = curl_exec($curl);
    curl_close($curl);
    $content = json_decode($content);
    $api_url = $content->api;
    $post_data["lang"] = "en";
    $post_data["convert_to"] = $convert_to;

    foreach ($file_list as $index => $file) {
        $post_data["file[$index]"] = curl_file_create(
            realpath($file),
            mime_content_type($file),
            basename($file)
        );
    }

    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $api_url."/v1/convert/");
    curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($curl, CURLOPT_POST, 1);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $post_data);
    curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    $content = curl_exec($curl);
    curl_close($curl);

    return array(json_decode($content), $api_url);
}

function get_results($params, $api_url, $headers) {
    if ($params->error) {
        print_r($params->error);
        return;
    }

    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $api_url."/v1/results/");
    curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($curl, CURLOPT_POST, 1);
    curl_setopt($curl, CURLOPT_POSTFIELDS, json_decode(json_encode($params), true));
    curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    $content = json_decode(curl_exec($curl));
    curl_close($curl);

    if ($content->finished == false) {
        if (intval($content->queue_count) > 0) {
            print_r("queue: $content->queue_count");
        }

        sleep(5);
        $results = get_results($params, $api_url, $headers);
        return;
    }

    foreach ($content->files as $f) {
        download_file($f->url, $f->filename, $api_url);
    }
}

$convert_to = "pdf-docx";
list($resp, $api_url) = convert_files($file_list, $headers, $convert_to);
get_results($resp, $api_url, $headers);
?>

const request = require('request');
const fs = require('fs');

let file_list = ['/path/to/file.pdf'];

function convertFiles(file_list, convert_to) {
    request({
        url: "https://www.epub.to/apis/",
        method: 'get',
    }, function(err, res, body) {
        if (err) {
            console.error(err);
            return err;
        }

        let api_url = JSON.parse(body).api;
        let formData = {
            'lang': 'en',
            'convert_to': convert_to
        };

        for (var i = 0; i < file_list.length; i ++) {
            formData['files'] = fs.createReadStream(file_list[i]);
        }

        request({
            url: `${api_url}/v1/convert/`,
            method: 'post',
            formData: formData,
            headers: {
                "Authorization": "api_key",
                "Content-Type": "multipart/form-data",
            }
        }, function(err, res, body) {
            if (err) {
                console.error(err);
                return err;
            }
            getResults(JSON.parse(body), api_url);
        });
    });
}

function getResults(data, api_url) {
    if (data.error) {
        console.error(data);
        return data.error;
    }
    request({
        url: `${api_url}/v1/results/`,
        method: 'post',
        formData: data
    }, function(e, r, body) {
        response = JSON.parse(body);

        if (!response.finished) {
            setTimeout(
                function() {
                    getResults(data, api_url);
                }, 1000
            );
            return;
        }

        console.log("Download URLs:");
        response.files.forEach(function (item) {
            if (item.url.startsWith('/')) {
                item.url = item.url.substring(1, item.url.length - 1);
            }
            console.log(`${api_url}/${item.url}`);
        });
    })
}

let convert_to = "pdf-docx"
convertFiles(file_list, convert_to);

/path/to/local/file_processed.docx