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 rather than chat bubbles, with nick colouring, BBCode and markdown, spoilers, code and quote blocks, inline image/video/YouTube embeds, reactions, replies, inline edit, and Sneedchat's bundled smilies. A "comfy" mode groups consecutive messages under one avatar.
• Settings - a category rail covering Display, IRC, Sneedchat, Tor, Matrix, Kick and the daemon itself. 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 accepts an invite and offers a friends list, 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 - SAS device verification, server-side key backup, and signing other sessions out, all under the account's own row in the Accounts pane. Verification is between your own sessions only: there is no cross-signing yet, so a session verified here is not verified in Element.
• 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/moho/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), NickServ auto-identify and GHOST reclaim, autojoin, optional SOCKS5 proxying, DCC send and receive, and the network's own colour codes. Twenty-four IRCv3 capabilities are negotiated, four 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, WHOIS, away, and channel modes passed through raw.

  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), password sign-in, 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, pinned messages, Discord's own search, invites made as well as accepted, server and channel mutes read from the account itself, voice calls with real audio (Songbird), and the account's own mute settings honoured. Where Discord asks for a captcha, it is shown in a window of moho's own rather than sending you to a browser. No video or screen share.

• Sneedchat (SneedChat) - the Tor-only chat built into Kiwi Farms. Runs over an embedded Tor client (or an external SOCKS5 proxy), solves the site's own proof-of-work anti-bot gate and the Tartarus captcha on its login form, 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 Tor session 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, knocking, reporting, room moderation, ignore lists, 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.

• 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, redemptions, subscriptions, gifted subs and raids, moderation, and polls and predictions that can be answered rather than only watched.

• XMPP/Slack - not implemented yet; listProtocols reports them as unavailable rather than leaving a frontend to guess.

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
~/.cache/moho/	re-derivable media caches (Matrix media, Sneedchat avatars/attachments)
$XDG_RUNTIME_DIR/moho/nobilis.sock	the daemon's control socket