dccbot

An IRC XDCC download bot written in python with aiohttp and irc.py.

Features

• join channels (auto-join on connect, with also_join cascades)
• send messages to channels or users
• NickServ authentication
• random nickname generation
• TLS/SSL server connections (with optional certificate verification bypass)
• DCC file transfer support (SEND / RESUME / SSEND)
• SSL DCC (SSEND) support
• passive DCC (incoming connections) with configurable listen IP and port range
• MIME type filtering for received files
• file size limits
• private IP filtering for DCC transfers
• transfer cancellation via API
• per-bot send queue throttling xdcc send requests to the same bot; numeric xdcc send/xdcc batch ranges (e.g. xdcc batch 1-5) are expanded into individual queued sends, so range requests also work on bots without batch support
• auto-disconnect from idle servers and channels
• MD5 verification of completed transfers
• incomplete file suffix support (auto-renamed on completion)

Installation

From source

git clone https://github.com/luni/dccbot.git
cd dccbot
uv sync
cp config.json.sample config.json
# edit config.json, then:
uv run python bot.py

From a release

Each release ships a wheel and a source distribution on the releases page:

uv tool install ./dccbot-0.4.0-py3-none-any.whl   # or: pipx install / pip install
dccbot --config /path/to/config.json

Running as a systemd user service

Copy dccbot.service to ~/.config/systemd/user/, adjust the paths in ExecStart to your install, then:

systemctl --user daemon-reload
systemctl --user enable --now dccbot
# optional: keep it running after logout
loginctl enable-linger "$USER"

Usage

Configuration

The bot can be configured by creating a config.json file in the current working directory. The configuration file should contain a json object with the following keys:

• servers: a dictionary of servers the bot can connect to, keyed by server address. Each server is an object with the following keys:
  • nick: the nickname to use when connecting to the server, default: dccbot
  • nickserv_password: the password to use when connecting to the server, optional
  • use_tls: a boolean indicating whether to use tls when connecting to the server
  • verify_ssl: a boolean indicating whether to verify the server ssl certificate
  • random_nick: a boolean indicating whether to use a random nickname when connecting to the server
  • port: the port to connect to, default: 6667
  • channels: a list of channels to join when connecting to the server, optional
  • also_join: a dictionary of channels to join if the specific channel is joined
  • rewrite_to_ssend: a list of channels to rewrite xdcc send to ssend for users in this channels
• default_server_config: same as servers, used if the server connected to is not in servers
• default_download_path: the directory where the bot should download files
• allowed_mimetypes: a list of mimetypes the bot should allow to be sent over dcc
• max_file_size: the maximum size of a file to be sent over dcc
• channel_idle_timeout: the number of seconds a channel can be idle before the bot will part the channel
• server_idle_timeout: the number of seconds a server can be idle before the bot will disconnect from the server
• resume_timeout: the number of seconds to wait for a resume response from the bot before aborting the transfer
• transfer_list_timeout: the number of seconds after a finished/aborted transfer is removed from the transfer list in /info response
• auto_md5sum: a boolean indicating to verify the md5sum of the file if the bot sends the md5sum as message on start of transfer or after successful transfer
• incomplete_suffix: a string that is appended to the filename while downloading. If file was transferred successfully this suffix is removed.
• ssend_map: a dictionary of users which support ssend (secure send). xdcc send command is replaced with xdcc ssend for these users. This tells the XDCC bot to use TLS-wrapped DCC (SDCC).
• rewrite_to_ssend: a list of channels where xdcc send is rewritten to xdcc ssend.
• allow_private_ips: a boolean indicating whether to allow private ips in dcc send command
• passive_dcc: A boolean indicating whether to accept passive DCC transfers (where the peer sends port=0 and a token, and the bot listens for an incoming connection). This option can also be set per-server.
• passive_dcc_listen_ip: The reachable IP address to bind and advertise the passive DCC listener on. If omitted, it defaults to the hostname's IP. 0.0.0.0 is treated as unset. This option can also be set per-server.
• passive_dcc_port_range: A list of two integers [min_port, max_port] defining the port range to try binding the listener to. If omitted, the OS assigns a port. This option can also be set per-server.
• passive_dcc_timeout: The number of seconds to wait for the peer to connect to the passive listener before aborting (default: 60). This option can also be set per-server.
• send_queue_delay: The minimum number of seconds between two queued xdcc send requests to the same bot (default: 15). This option can also be set per-server.
• send_queue_cooldown: The number of seconds the bot must go without an active transfer (after send_queue_delay) before the next queued xdcc send to it goes out; a transfer starting in the meantime, e.g. the next file of an xdcc batch, restarts it (default: 5). This option can also be set per-server.
• send_queue_max_wait: The maximum number of seconds an active transfer may go without any progress before the queue moves on to the next item anyway, so a stuck transfer cannot stall the queue (default: 300). This option can also be set per-server.
• send_queue_max_concurrent: The maximum number of queue-triggered transfers allowed to run at the same time across all bots and servers (default: 0, meaning unlimited). Global only; sends to the same bot are always serialized per target regardless.
• dcc_ssl_cert: Optional path to a PEM certificate file for SDCC (SSEND). If provided, dcc_ssl_key must also be set.
• dcc_ssl_key: Optional path to the PEM private key for dcc_ssl_cert. If either is omitted, a self-signed certificate is generated and cached in ~/.local/share/dccbot/.
• http: a dictionary with the following keys:
  • socket: the path to the socket to use for the http server (instead of host and port)
  • port: the port to bind the http server to, default: 8080
  • host: the host to bind the http server to, default: localhost
  • legacy keys bind_addr and bind_port are still accepted for compatibility

API

The bot can be controlled using a simple web interface. The web interface is available at http://localhost:8080/ by default.

• POST /join: join a channel
• POST /part: part a channel
• POST /msg: send a message to a channel or user (queued per target, see send_queue_*)
• POST /cancel: cancel a running transfer
• POST /shutdown: shutdown the bot
• GET /info: get information about the current status of the bot (networks, current transfers, finished transfers, pending send queues)
• GET /ws: WebSocket endpoint for live transfer/queue updates and log streaming
• GET /swagger: interactive OpenAPI/Swagger UI documentation
• GET /static/: static web assets (unified web UI)

Additional browser features

• /: unified web UI with current transfers, live log output, and websocket command input.

WebSocket command help

In the browser command input, use:

• /help to show all websocket commands and signatures
• /help <command> to show usage and an example for a single command

Supported websocket commands:

• /help [command]
• /join <server> <channel> [<channel> ...]
• /part <server> <channel> [<channel> ...]
• /msg <server> <target> <message>
• /msgjoin <server> <channel> <target> <message>
• /info
• /queue
• /cancelqueue <server> <target> [index-or-message]

Browser Userscript for Easy Downloads

A Violentmonkey userscript is provided to add download buttons to popular XDCC search websites, making it easy to send download commands directly to your DCCBot.

Supported Websites

• XDCC.eu
• NIBL
• xdcc.rocks
• xdcc.animk.info
• xdcc-search.com
• xdcc.info
• skullxdcc.com
• xdccsearch.com

Installation

1. Install the Violentmonkey extension for your browser (open source and available for Chrome, Firefox, and other Chromium-based browsers)
2. Click the following link to install the script: Install Script

Configuration

1. After installation, click on the Violentmonkey extension icon
2. Open the installed add-dccbot-btn script's menu and choose "Set API Endpoint"
3. Enter your DCCBot API endpoint (e.g., http://localhost:8080)

Usage

• On supported sites (XDCC.eu, NIBL, xdcc.info, etc.), you'll see a "Down" button next to each search result
• Click the button to automatically send the download command to your DCCBot
• For NIBL, you can also select multiple items and use the "Download selected" button to batch download

Features

• One-click downloads from supported websites

• Batch download support on NIBL

• Customizable API endpoint

• Lightweight and fast

Developer / Testing

The repository includes a full local development and testing setup:

• Makefile targets: make test, make test-integration, make irc-up, make irc-down, make mutation, make validate (format + lint + complexity + security + type-check + vulture)
• Docker Compose: docker compose up -d ircd starts a local InspIRCd test server for integration tests; make irc-up additionally starts the iroffer XDCC bot and a toxiproxy sidecar for network fault-injection tests
• Mutation testing: make mutation runs mutmut against dccbot/ (nightly in CI via .github/workflows/mutation.yml, results uploaded as an artifact)
• Fault injection / negative paths: tests/unit/test_fault_injection.py and tests/unit/test_negative_paths.py cover injected filesystem/network/queue failures and malformed inputs; tests/integration/test_fault_injection.py injects real network faults (latency, resets, truncation, throttling) via toxiproxy
• Dependabot: configured for pip (weekly) and GitHub Actions (monthly)

Contributions & Thanks

Contributions are welcome — open an issue or pull request on GitHub. Please make sure make validate and the test suite pass before submitting a PR.

Thanks to everyone who has contributed to DCCBot:

• Vincent Schoonenburg (@arkancrow) — per-bot send queue for xdcc send requests (PR #36)