moho/ARCHITECTURE.md

moho architecture

How the two halves fit together, what the daemon speaks, and where it puts things. The README is the short version; this is everything else.

Why two parts

• nobilis (nobilis/, Rust) speaks each protocol directly and translates it into a small unified JSON model (accounts, buffers, messages) over a Unix socket. It never exposes protocol-specific concepts to the client; it speaks the unified model, and each backend module happens to be how that model gets populated for a given service.
• The Electron client (src/) spawns and supervises nobilis and renders whatever it reports.

Keeping the protocol work in a separate long-lived daemon means connections, Tor circuits, and Matrix sync survive the UI being closed, restarted, or reloaded during development.

nobilis/src/backend/    one module per protocol (irc, discord, sneedchat, matrix, kick)
nobilis/src/rpc/        the Unix-socket JSON-RPC server
nobilis/src/store.rs    SQLite-backed scrollback persistence
nobilis/src/runtime.rs  protocol-agnostic connection/buffer/message state
src/main/               Electron main: daemon supervision, RPC socket, tray, notifications
src/preload/            the contextBridge surface exposed to the renderer
src/renderer/           React UI: buffer list, message log, member list, accounts, settings
resources/icons/        bundled artwork (service marks, IRC network logos, tray icons)

One daemon, many clients

Every packaged form bundles nobilis, the Sneedchat smilies and the icons under resources/, and the app resolves them from there rather than from the source tree - so the app and the daemon in one download always match.

nobilis holds an flock-based singleton lock on its data directory, so launching a second client does not start a second daemon — it attaches to the running one. Quitting the app sends the daemon a clean shutdown (real QUITs to IRC, rather than dropping the connections), so your nick isn't left ghosted.

The client

Three panes: an account-grouped buffer sidebar, the message log, and a member list, with the sidebar and member list independently foldable. Closing the window hides it to the tray; nobilis keeps running, so connections and unread tracking survive.

• Message rendering - an IRC-style log by default, with nick colouring, BBCode and markdown, spoilers, code and quote blocks, inline image/video/YouTube embeds, custom emoji, emotes and stickers (Discord's animated Lottie ones included), reactions, replies, inline edit, and Sneedchat's bundled smilies. "Comfy" groups consecutive messages under one avatar, and "Bubbles" draws them as chat bubbles.
• Settings - a category rail covering General, IRC, Sneedchat, Tor, Discord, Matrix, Kick and About. Message-kind filters (joins, parts, mode changes) are applied client-side, so toggling one takes effect immediately without a reconnect.
• Per-protocol join pages - each service's mechanism is genuinely different (IRC joins by channel name, Discord offers the friends list and sends joining, adding a friend and making a server to discord.com - see below - Matrix takes a room address or searches every homeserver's directory at once, Sneedchat lists the rooms the site itself publishes, Kick takes a streamer's handle), so each gets its own page.
• Matrix security - device verification by emoji or QR, cross-signing, server-side key backup, key export and import, and signing other sessions out, all under the account's own row in the Accounts pane. A session verified here is verified in Element too.
• Service interruptions - a conversation that is not receiving is drawn in italics, with a spinner while something is trying, and says why in a banner when opened: its account is reconnecting, an IRC channel refused the join, a Kick channel is still being looked up. A Sneedchat room that cannot connect is diagnosed - Tor, the forum, or only the chat - by checking the route, then the forum's front page, then concluding it is the chat.
• Calls and streams - a call stage like Discord's, which can sit in the corner or pop out into a window of its own, with tiles per person, volume per person and for the whole call on their right-click menu, and the camera and screen buttons in one row. A Kick stream is drawn in the same surface, resizable in the corner or popped out.
• Tagging - typing "@" lists the people here, the roles the service lets anybody ping, and its whole-room words, matched fuzzily. What is sent is what the service understands: an id on Discord, m.mentions on Matrix, "nick: " on IRC.
• Profiles - right-click somebody in the member list or on a message. Each service answers what it keeps: an idle time and shared channels on IRC, an account age and a join date on Discord, a power level and a last-seen on Matrix.

Security notes

Message bodies are fully attacker-controlled. The renderer runs with contextIsolation and no Node integration, and its preload surface is a fixed list of calls - there is no ipcRenderer passthrough and no filesystem access. Formatted message HTML is never injected directly: it is parsed into an inert document and rebuilt through a tag and attribute whitelist, so unknown tags degrade to text and javascript:/data: URLs, inline event handlers and <script> cannot survive. Local media nobilis has fetched is served through a dedicated scheme that resolves only inside the known cache directories, rather than by disabling webSecurity.

No plugins, and no scripting

moho does not have a plugin API or a scripting language, and will not grow one. This is a decision rather than a gap, and it is the same decision as everything above: the client does not execute code.

It is the one place moho deliberately falls short of the clients it is otherwise measured against — HexChat has Perl and Python, WeeChat has Lua, Python, Perl and Ruby, mIRC has its own language — so a comparison that counts scripting will always find moho missing it, and that is the intended answer rather than a backlog item.

The reasoning is that a scripting host is an execution surface pointed at exactly the data that is fully attacker-controlled. Every mitigation above — the fixed preload surface, the tag and attribute whitelist, the media scheme — exists to keep message content from ever becoming something that runs. A plugin API hands that back in one step, and does it with more privilege than the renderer has: scripts want the filesystem, the network and the message stream, which is the whole of what an attacker would ask for. The daemon/client split makes this cheaper to hold to than it would otherwise be, since anything that genuinely needs to automate moho can speak the wire protocol in Wire protocol below as a separate process, with its own permissions and its own blast radius.

Global hotkey on Wayland

The show/hide hotkey (Control+Shift+M by default, configurable) uses Electron's globalShortcut, which only works under X11 — Wayland compositors do not let an ordinary client grab keys globally. Under Wayland the registration is refused, logged, and otherwise ignored; bind the compositor to focus the window instead.

Wire protocol

Newline-delimited JSON over a Unix socket at $XDG_RUNTIME_DIR/nobilis/nobilis.sock:

request:  {"id": 1, "method": "sendMessage", "params": {...}}
response: {"id": 1, "result": {...}}  or  {"id": 1, "error": "..."}
push:     {"event": "message", "data": {...}}

Core methods: listAccounts, listBuffers, listProtocols, addAccount, removeAccount, setAccountConnected, joinBuffer, partBuffer, sendMessage, editMessage, deleteMessage, subscribe/unsubscribe, getBacklog (SQLite-backed, persists across nobilis restarts), searchMessages, requestProfile, markBufferRead. Each protocol also has its own account-creation method (addAccount for IRC, addDiscordAccount, addSneedChatAccount, addMatrixAccount, addKickAccount) and its own verbs beyond the shared ones - the full list is the match in nobilis/src/rpc/methods.rs, which is the only place it cannot go stale.

Requests are answered concurrently, so a slow one - a room-directory search across several homeservers, a Tor round trip - does not hold up anything else on the same connection. Responses carry the id of the request they answer and may arrive in any order.

Push events: message, messageUpdated, messageDeleted, reactionsChanged, presenceChange, bufferListChange, connectionState, notification, profile, readReceipts, plus per-protocol login-flow events (discordLoginQr/discordLoginScanned/discordLoginResult, sneedChatLoginStatus/ sneedChatLoginResult, matrixLoginStatus/matrixLoginResult). message, presenceChange, messageUpdated, messageDeleted and reactionsChanged are only delivered to clients that called subscribe for that buffer.

Protocol backends

• IRC - TLS with SASL (PLAIN, EXTERNAL, SCRAM-SHA-256), STS, NickServ auto-identify and GHOST reclaim, autojoin, optional SOCKS5 or Tor, DCC send and receive with resume, and the network's own colour codes. Twenty-seven IRCv3 capabilities are negotiated, six of them drafts, alongside SASL and WHOX - which a network advertises in ISUPPORT rather than as a capability. Among them: echo-message and labeled-response, so a sent line is the one the server actually delivered rather than this client's guess at it; chathistory in both spellings for server-side backfill; draft/multiline, so a long message is continued rather than cut at 512 bytes; draft/message-redaction, so a deleted message leaves the screen; userhost-in-names and account-tag, so a join says who somebody is rather than only what they are called. Typing over +typing, a notify list over MONITOR with extended-monitor, avatars over METADATA, WHOIS, away, and channel modes passed through raw. Images are uploaded to catbox, postimg, ibb.co or imgur and sent as a link, since IRC itself carries only text.

  The list negotiated is WANTED_CAPS in nobilis/src/backend/irc/connect.rs, filtered against what the server offered in CAP LS - one REQ line with only the advertised ones, because twenty-odd REQ lines trip flood protection on a real network.

• Discord - official cross-device QR login (the same one discord.com/app offers), Discord's own sign-in page in a window moho opens, or a token; a real-time gateway client over the user gateway. Messages with edit/delete/reactions/replies/forwarding, threads and forum posts, slash commands with buttons, menus and modal forms, polls that can be voted in, stickers sent and drawn, pinned messages, Discord's own search, invites, scheduled events, AutoMod's verdicts, and server and channel mutes read from the account itself.

  Voice and video are moho's own connections rather than a library's: voice, the camera and Go Live streams - hosted and watched, with sound - over Discord's RTP with DAVE end-to-end encryption, VP8 encoded and decoded in the window. Echo cancellation and noise suppression (WebRTC's audio processing, in Rust), per-person and call volume, the soundboard both ways, and stage channels.

  Joining a server, adding a friend and making a server are deliberately not done here. Discord puts each behind an hCaptcha when it comes from anything but its own client, and a third-party client answering one is what gets an account flagged for spam - so moho opens discord.com for them, and says why beside the button. A captcha that turns up anywhere else is refused the same way rather than answered.

• Sneedchat (SneedChat) - the chat built into Kiwi Farms. On the open internet by default, or per account over an embedded Tor client (or an external SOCKS5 proxy) at the onion address. Solves the site's own proof-of-work anti-bot gate and the Tartarus captcha on its login form, with two-factor, and connects to every configured room simultaneously (one persistent websocket per room, sharing a single login). Message edit/delete, whispers, attachments (uploaded to postimg, since the chat itself is text-only), and avatars fetched through the same route and cached locally.

• Matrix - Client-Server API with full end-to-end encryption (vodozemac-backed Olm/Megolm via matrix-sdk-crypto), SAS device verification, cross-signing, server-side key backup and key import/export, encrypted attachments. Threads, read receipts, spaces (created and filled), polls, stickers, forwarding (the original content sent again, as Element does), knocking, reporting, room moderation, widgets, ignore lists, sliding sync, and a room directory search that asks every homeserver this account knows at once. Calls both ways: one-to-one signalling, and the group calls Element holds on a LiveKit media server, with the media keys the room passes round. Camera and screen share in all three shapes of call - a single connection, a mesh, or a media server - and either can be turned on part-way through, which is a renegotiation rather than a new call.

• Kick - the streaming site's chat, over its Pusher socket. Joins by streamer handle, imports the account's follows, and carries the three emote tiers with subscriber gating (and 7TV and BTTV beside them), redemptions, subscriptions, gifted subs and raids, moderation, chat modes, and polls and predictions that can be answered rather than only watched. The stream itself plays in the window over HLS, with its VODs and clips.

On-disk state

Path	Contents
~/.config/nobilis/accounts.toml	account config and credentials
~/.config/nobilis/scrollback.db	SQLite scrollback
~/.config/nobilis/matrix-crypto/	Matrix E2EE device keys and Olm sessions
~/.config/nobilis/voice.toml	microphone, speakers, volumes and voice processing
~/.config/nobilis/tor-state/, tor-cache/	the embedded Tor client's state
~/.cache/nobilis/	re-derivable media caches (Matrix media, Discord thumbnails, stickers and sounds, Kick emotes, Sneedchat avatars and attachments), each held to a size and to thirty days, and fetched again when a missing file is looked at - see nobilis/src/media_cache.rs
~/.cache/moho/moho.log	the app's log, the daemon's included
$XDG_RUNTIME_DIR/nobilis/nobilis.sock	the daemon's control socket