A small recipe that can be useful for the curious people.

A .dlm file is a gzip-compressed tar archive containing two files that Synology’s Download Station uses to search torrent sites.

Archive Structure

my_plugin.dlm (tar.gz)
├── INFO          # Plugin metadata (JSON)
└── search.php    # Search logic (PHP class)

INFO File

A JSON file describing the plugin. Example:

{
  "name": "my_plugin",
  "displayname": "My Torrent Site",
  "description": "Search torrents on example.com",
  "version": "1.0",
  "site": "https://example.com/",
  "module": "search.php",
  "type": "search",
  "class": "SynoDLMSearchMyPlugin"
}

Fields

Field Required Description
name Yes Internal identifier (no spaces)
displayname Yes Name shown in Download Station UI
description Yes Short description
version Yes Plugin version string
site Yes URL of the torrent site
module Yes PHP filename (always search.php)
type Yes Always search
class Yes PHP class name — must match exactly in both files
accountsupport No true if the site requires login (changes prepare() signature)

search.php

A PHP class implementing two required methods: prepare() and parse().

Method Signatures

The prepare() signature depends on accountsupport in INFO:

  • accountsupport is false or absent: 
    public function prepare($curl, $query)
  • accountsupport is true: 
    public function prepare($curl, $query, $username, $password)

This is critical — using the wrong signature causes a silent PHP fatal error and the plugin will not work.

prepare($curl, $query)

Configure the cURL handle that Synology will execute. You set the URL, headers, and options here. You do not execute the request yourself.

public function prepare($curl, $query) {
    $url = 'https://example.com/api/search?q=' . urlencode($query);

    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_HTTPHEADER, ['Authorization: Bearer MY_KEY']);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt($curl, CURLOPT_TIMEOUT, 20);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
}

parse($plugin, $response)

Receives the raw HTTP response body (string). Parse it and call $plugin->addResult() for each torrent found. Return the number of results.

public function parse($plugin, $response) {
    $json = json_decode($response, true);
    $res = 0;

    foreach ($json['results'] as $item) {
        $plugin->addResult(
            $title,      // string: torrent name
            $download,   // string: .torrent URL or magnet: link
            $size,       // int: size in bytes
            $datetime,   // string: date in "Y-m-d" format
            $page,       // string: URL to the torrent page
            $hash,       // string: unique identifier (infohash or md5 of title)
            $seeds,      // int: number of seeders
            $leechs,     // int: number of leechers
            $category    // string: category label
        );
        $res++;
    }

    return $res;
}

addResult() Parameters

# Name Type Description
1 title string Torrent display name
2 download string .torrent URL or magnet: URI
3 size int File size in bytes
4 datetime string Upload date (Y-m-d format)
5 page string URL to the torrent detail page
6 hash string Unique ID (typically the infohash)
7 seeds int Seeder count
8 leechs int Leecher count
9 category string Category label (e.g. "Films: HD")

Debugging

Add a debug logger to your class:

private $debug = true;

private function DebugLog($str) {
    if ($this->debug) {
        file_put_contents('/tmp/my_plugin.log', $str . "\n", FILE_APPEND);
    }
}

Then SSH into the Synology and tail -f /tmp/my_plugin.log while running a search.

Set $debug = false for production.

Building the .dlm

From the directory containing INFO and search.php:

tar czf my_plugin.dlm INFO search.php

Installing

  1. Open Download Station on your Synology
  2. Go to Settings > BT Search
  3. Click Add and upload the .dlm file
  4. Enable the plugin with the checkbox