I am trying to upload a file from my local server to the Paperless NGX API using PHP. The API requires a CSRF token and Basic Authentication for the POST request. However, I am having trouble obtaining the CSRF token and making the request successfully. Here is the code I have written so far:

1. Getting the CSRF Token:

$apiUrl = 'http://hostname:8000/api/documents/post_document/';
$filePath = '/path/to/file.pdf';
$username = 'username';
$password = 'password';

function getCsrfToken($apiUrl, $username, $password) {
    $ch = curl_init();

    curl_setopt($ch, CURLOPT_URL, $apiUrl);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HEADER, true);
    curl_setopt($ch, CURLOPT_NOBODY, true);
    curl_setopt($ch, CURLOPT_USERPWD, "$username:$password");

    $response = curl_exec($ch);
    $headers = [];
    $header_text = substr($response, 0, curl_getinfo($ch, CURLINFO_HEADER_SIZE));
    foreach (explode("rn", $header_text) as $i => $line) {
        if ($i === 0) {
            $headers['http_code'] = $line;
        } else {
            list ($key, $value) = explode(': ', $line);
            $headers[$key] = $value;
        }
    }

    curl_close($ch);

    return $headers['X-CSRFToken'] ?? null;
}

$csrfToken = getCsrfToken($apiUrl, $username, $password);

if (!$csrfToken) {
    die('CSRF-Token could not be retrieved');
}

2. Uploading the file:

    $ch = curl_init();

    $file = new CURLFile($filePath);

    $postData = [
        'document' => $file
    ];

    curl_setopt($ch, CURLOPT_URL, $apiUrl);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_USERPWD, "$username:$password");
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'X-CSRFToken: ' . $csrfToken,
        'Content-Type: multipart/form-data'
    ]);

    $response = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

    curl_close($ch);

    if ($httpCode == 201) {
        echo 'File uploaded successfully!';
    } else {
        echo 'Error uploading file: ' . $response;
    }
}

uploadFile($apiUrl, $filePath, $csrfToken, $username, $password);

However, when I run this code, I receive a “405 Method Not Allowed” response when attempting to get the CSRF token. I suspect that the API URL I am using to get the CSRF token is incorrect, or the method I am using to retrieve it is not supported.

Could anyone provide guidance on how to properly retrieve the CSRF token and successfully upload a file to the Paperless NGX API with Basic Authentication in PHP?

Thank you!