AirDC++ source ​

The AirDC++ plugin adds Direct Connect (DC++) as a download source. It talks to a running AirDC++ instance through its Web API — searching the hubs you're connected to, queueing the match, and importing the finished file like any other download.

It's an immediate source: BackIssue searches, downloads, and imports inline (no external "grab then monitor later" step). Because DC is peer-to-peer over hubs, it fills gaps that Usenet and torrents leave — but it comes with etiquette and rate limits that are worth understanding before you lean on it.

What you need ​

• A running AirDC++ instance (desktop or the web/headless build) that is:
  • connected to one or more hubs, and
  • sharing — hubs expect give-and-take; a client that only downloads gets kicked or banned on most hubs (more below).
• The AirDC++ Web API enabled, with a username and password.

Setup ​

In Settings → Sources, enable AirDC++ and fill in:

• Web API URL — where AirDC++'s Web API listens, e.g. http://192.168.1.109:5600.
• Username / Password — a Web API account on that AirDC++ instance.
• Hub URLs (optional) — restrict searches to specific hubs (comma-separated, e.g. adcs://hub.example:2780). Blank searches all connected hubs.
• Download folder — a two-path mapping, exactly like the Usenet/torrent completed-folder mapping, for when AirDC++ and BackIssue see the filesystem differently (separate machines, Docker, SMB):
  • AirDC++'s view — where AirDC++ writes finished downloads (its own path).
  • BackIssue's view — the same folder as BackIssue reads it (e.g. \\TOWER\downloads\comics).

BackIssue copies the finished file in rather than moving it, so AirDC++ keeps the copy and keeps sharing it.

How it works ​

• One search per volume. When you download several issues of the same series, BackIssue runs a single hub search for the series name and picks each issue's match out of the shared results — not one search per issue. This is deliberate: DC searches are the slow, rate-limited part (see below), so a 20-issue grab costs roughly one search, not twenty. Issues the shared search doesn't cover fall back to an individual search.
• Adaptive polling. DC results arrive from peers over several seconds; BackIssue polls and returns as soon as a confident match arrives.
• Corruption guard. DC verifies a transfer matches the peer's bytes, not that the file is a valid archive. BackIssue sniffs each finished file and, if it isn't a real comic archive, deletes it and blacklists that copy for the run so a retry picks a different peer.

Search limitations ​

DC is not an indexed API — it's a live query across peers — so searches behave differently from Usenet/torrent indexers:

• Searches run one at a time, spaced by a cooldown. Hubs rate-limit searches; firing many at once makes them cancel each other. BackIssue serialises them (default ~3s apart), so bulk downloads are slow but reliable rather than fast and flaky. Expect a large series to take a while.
• Coverage depends on who's online and sharing. A well-seeded modern series is found in seconds. An older or thinly-shared series (or an unusual release naming) may not appear in the series search, dropping each of its issues into the slower per-issue fallback.
• Not-found isn't instant. A search that returns nothing gives up after a few seconds (the Give up if empty setting, default 5s) rather than waiting the full maximum — but across many missing issues that still adds up.
• No result ≠ file doesn't exist. A single DC search occasionally misses even when the file is shared (it just didn't reach the right peers in the window). BackIssue retries an empty search a small number of times — but keep that number low, for the reason in the next section.

Watching announce bots ​

Many hubs run announce bots — users that post a message (with a magnet link) every time a new file is uploaded. BackIssue can watch them and grab anything you're missing, minutes after it appears:

1. In Settings → Sources → AirDC++, set Watch bot nicks to the bot's username (comma-separated for several). Messages from those users are scanned wherever they appear — their private messages to you and lines they post in main chat.
2. On the Jobs page, enable Watch AirDC++ announcements (default cadence: every 15 minutes).

Each run reads the bots' recent messages (each message is considered exactly once), parses the announced magnet links, and matches the filenames against missing issues of monitored series — the same strict matching the other sources use, aliases included. A match downloads immediately, and by the announcement's exact file hash (TTH), so you get precisely the announced copy rather than a re-search by name.

The Logs page (category airdcpp) shows every bot message once, each announced file's matched/unmatched verdict, and a per-run summary — so it's easy to confirm the bot's format parses and the matches are what you expect.

Avoiding hub bans and flags ​

Settings ​

All under Settings → Sources → AirDC++:

Troubleshooting ​

• "Authentication failed" — check the Web API URL, username, and password, and that the Web API is enabled in AirDC++.
• Searches return nothing for files you know are shared — you may be tripping the repeat-search flag; set Retry empties to 0 and confirm the series name matches how peers name their files.
• "AirDC++ has the file on disk but BackIssue can't find it" — your Download folder (BackIssue's view) doesn't match where AirDC++ actually writes. Set it to AirDC++'s real download directory (the same folder, as BackIssue reads it).
• Bulk grabs are slow — expected. Serial, rate-limited searching is what keeps you on good terms with the hubs; see Search limitations.