Conduit

A focused, native Slack client for the GNOME desktop.

Conduit is a Rust, GTK4, libadwaita, and WebKitGTK desktop client that aims to make the everyday parts of Slack feel fast and at home on Linux. It combines native workspace navigation and composers with an app-generated message timeline that escapes Slack-provided content.

The app is becoming usable as a daily driver for focused messaging, but it is still a young project. Expect gaps outside the core conversation workflow and occasional changes to setup or behavior before a stable release.

Conduit is an independent project and is not affiliated with or endorsed by Slack Technologies, LLC.

What works today

Conversations and navigation

• Adaptive GNOME interface for channels, direct messages, and group messages.
• Complete paginated catalog of subscribed channels, DMs, and group DMs, with persisted metadata and unread state. The default sidebar keeps relevant DMs compact; Show All Conversations and the conversation switcher expose the full catalog.
• A Priority section mirrors Slack conversation stars, listing starred DMs as VIP conversations before starred channels. Sidebar context menus can star or unstar channels and DMs, and one-to-one DMs expose a Profile action.
• Sections for Messages, Unreads, observed threads, Files, and Later.
• Fast conversation switcher with discovery of channels and people.
• Create public or private channels, start direct or group messages, and add people to existing conversations when Slack permissions allow it.
• GNOME Shell search-provider integration for opening cached channels, existing direct messages, and new direct messages with cached workspace members straight from the desktop overview. It reads only conversation and name metadata for the active workspace and never indexes message history.
• Transactional SQLite caching for conversations, names, histories, threads, unread state, statuses, and custom emoji, with automatic migration from the earlier JSON cache.
• Unread badges, muted and external-conversation indicators, read markers, and relevant-only desktop notifications for direct messages, mentions, configured terms, and interested-thread replies.
• Slack status emoji and hover text for people in direct messages, shown consistently in navigation, switchers, titles, and message authors.
• The workspace header shows your display name and active custom status. Its menu opens a native status editor with searchable emoji, expiration choices, and explicit clearing.
• Multi-word, case-insensitive substring filtering with globally ranked, category-free results across conversation, forwarding, message, and emoji searches. Conversation ranking treats direct messages and people as one-person groups, while group DMs use the share of other participants whose names match; group titles omit your own name.

Messaging

• Paged channel history and threaded replies.
• Multiline message and thread composers with persistent per-conversation drafts and person completion after typing @.
• File uploads with progress reporting, including pasting clipboard screenshots directly into either composer.
• Emoji and person completion with type-ahead filtering and keyboard navigation in main messages and threads. Completed people remain readable by name while being sent to Slack as real mentions.
• Edited and deleted messages, Slack links and mentions, user-group mentions, common Block Kit and legacy bot attachments, bot identities, code blocks, and image and video previews.
• Safe bot links open directly; callback buttons and menus open the exact originating message in Slack so the publishing app remains responsible for the interaction.
• Workspace custom emoji in messages, reactions, composer completion, and the reusable searchable emoji picker.
• Add and remove reactions, save messages for Later, copy message text or links, and forward messages.
• Message authors use cached avatars with initial fallbacks. Author names and @mentions expose Message and Profile actions; hovering shows the person's full name when available, falling back to the display name.
• Message timelines follow the GTK system text size and GNOME text scaling without applying other system theme settings to their content.

Search, files, and media

• Workspace message search with Slack modifiers such as from:, in:, and has: preserved.
• A persistent Threads inbox assembled from fetched history, opened threads, realtime replies, and Slack subscription/unread metadata.
• Relevance-ranked multi-term results while retaining Slack's own result order for close matches.
• Files and saved-item views with navigation back to their source messages.
• Slack message permalinks for the connected workspace open directly inside Conduit.
• Official slack:// links can activate Conduit from the desktop or a browser and open channels, direct messages, and files in the connected workspace.
• Internal image and video viewer with galleries, zoom, fullscreen, context actions, and Save As.
• Unsupported Slack attachments download through authenticated, size-bounded local caching and open in the system's default application; old cache entries are evicted automatically.

Huddles

• Active huddles are discovered from supported Slack conversation and presence data and shown only in the matching workspace and conversation.
• A camera-off preflight shows the available media choices without starting capture, and privacy-safe desktop notifications open the matching conversation.
• Until a verified Slack/Amazon Chime join bridge is available, Conduit opens the exact huddle in Slack over HTTPS. The optional native media stack is a generic WebRTC engine and synthetic harness, not a production Slack join implementation.

Sync and resilience

• Network and cache work runs away from the GTK UI thread, with short connection, request, and Socket Mode liveness deadlines.
• Optional Slack Socket Mode ingestion for message, reaction, and conversation updates.
• Realtime messages, user changes, and reactions use a session-owned ordered actor with an unbounded callback queue and opt-in live high-water diagnostics; messages are cached for unopened conversations, and unread DMs are prioritized for background history refresh.
• Automatic Socket Mode reconnect with capped backoff.
• Scoped loading and error recovery so failures in one surface do not replace unrelated content.
• Workspace inputs are normalized through a revisioned coordinator behind compatibility adapters, while the WAL-backed SQLite cache applies incremental entity updates and supports concurrent desktop search reads.
• Tokens are validated with auth.test and stored through the system Secret Service/keyring.

Current limitations

• Conduit intentionally manages one connected Slack workspace session at a time.
• OAuth requires your own Slack app unless a packaged build supplies a client ID.
• Slack does not expose its separate paid-plan VIP preference through the public API, so Conduit's VIP projection consists of starred DMs.
• Socket Mode is optional and requires separate Slack app configuration and an xapp- token.
• Workspace search is bounded by Slack's search API and cannot guarantee arbitrary middle-of-word discovery outside the candidates Slack returns.
• Slack's public API cannot enumerate every historical subscribed thread. Conduit retains and reconciles every thread it discovers, but a fresh installation builds its thread catalog progressively as history and replies are fetched.
• Threads and Unreads reflect the conversations and activity Conduit has observed; they are not complete Slack-wide activity aggregators.
• File and workspace-search views currently load a bounded result set rather than every page.
• Rich composer formatting, autocomplete beyond emoji and people, message editing/deletion controls, typing indicators, general live presence, sidebar avatars (message and profile avatars are supported), native production huddle joining, canvases, workflows, custom sidebar sections, and full Slack administration are not implemented.
• Release bundles currently target x86_64 Debian 13, Fedora 44, and Flatpak. Other distributions and architectures still require a source build.
• Signing out removes the stored credential and clears the active-workspace selection, but it does not currently purge cached workspace data or saved drafts from local storage.

Install a release

Each GitHub Release includes packages for Debian 13 (Trixie), Fedora 44, and a GNOME 50 Flatpak bundle, plus SHA256SUMS. Download one package and install it with the matching system tool:

# Debian 13
sudo apt install ./conduit_VERSION-1_amd64.deb

# Fedora 44
sudo dnf install ./conduit-VERSION-1.fc44.x86_64.rpm

# Any Flatpak host with the Flathub runtime remote
flatpak install --user ./conduit-VERSION-x86_64.flatpak

The single-file Flatpak bundle is installable but does not provide automatic updates. Conduit is not currently published on Flathub. See the release guide for release maintenance, verification, and the current Flathub boundary.

General release packages keep the optional native huddle media and screen-sharing stack disabled until production Slack joining is available. Huddle discovery and the exact Open in Slack fallback remain supported.

Build and run

Install Rust, Meson, Ninja, PyGObject with GdkPixbuf introspection, and the development packages for GTK4, libadwaita, WebKitGTK 6.0, GLib/GIO, D-Bus, gettext, and Secret Service. Package names vary by distribution.

Build and test with Meson:

meson setup _build
meson compile -C _build
meson test -C _build

Run the development build directly:

_build/src/conduit

The binary expects conduit.gresource beside it or in the configured package-data directory, so a Meson build or installation is recommended over invoking cargo run directly.

To install under a local prefix:

meson setup _build --prefix="$HOME/.local" --reconfigure
meson compile -C _build
meson install -C _build

Rerunning the install upgrades an existing source installation. Conduit's install hook removes known obsolete branding files from earlier versions before Meson refreshes the GNOME icon and desktop caches, so manual cache deletion is not required. Fully quit and reopen Conduit after an upgrade. If GNOME Shell keeps an already-rendered application icon, sign out and back in once.

To remove the files recorded by the most recent install from that build directory:

ninja -C _build uninstall

Use the same build directory and permissions that were used for installation.

Useful Rust-only checks while developing:

cargo fmt --check
cargo clippy --locked --all-targets -- -D warnings
cargo test --locked

Native huddle media is optional. It requires GStreamer 1.24 or newer; portal-based screen sharing additionally uses PipeWire and xdg-desktop-portal. See Slack huddles for Debian packages, Meson feature flags, the synthetic test command, privacy guarantees, and the current Slack/Amazon Chime interoperability boundary.

Open Slack links with Conduit

An installed Conduit desktop entry advertises support for Slack's official slack:// scheme. Conduit does not change the current default handler during installation. To inspect the current choice and select Conduit explicitly:

xdg-mime query default x-scheme-handler/slack
xdg-mime default eu.vanadrighem.conduit.desktop x-scheme-handler/slack

Save the first command's output if you may want to restore the previous handler later. Run the second command again with that desktop ID to restore it.

Conduit accepts Slack's open, channel, user, file, share-file, and app URI forms. Channels, direct messages, and files use native Conduit surfaces. App links use Slack's official HTTPS app_redirect fallback, which opens the app or bot conversation and cannot preserve a requested App Home tab. The share-file form opens the file but reports that sharing an existing file is not yet supported. Workspace-scoped links must match the currently connected Slack team; Conduit will not open a same-shaped target from another workspace.

Firefox, Chromium, and other browsers normally show an external-protocol confirmation before handing a slack:// URI to the selected desktop application. Conduit does not install a browser extension and does not claim http or https, so an ordinary Slack web link remains in the browser unless Slack itself turns it into a slack:// request.

Connect a Slack workspace

Recommended: OAuth with PKCE

Create a Slack app, configure user-token OAuth, and add this redirect URL. Conduit performs the authorization using PKCE:

http://127.0.0.1:8934/callback

Configure these user scopes:

channels:read,channels:history,channels:join,channels:write,
groups:read,groups:history,groups:write,
im:read,im:history,im:write,
mpim:read,mpim:history,mpim:write,
users:read,users:read.email,users.profile:read,users.profile:write,usergroups:read,emoji:read,
chat:write,search:read,
stars:read,stars:write,
reactions:read,reactions:write,
files:read,files:write

Provide the client ID in one of three ways:

• Enter it on Conduit's connection screen.

• Set CONDUIT_SLACK_CLIENT_ID before starting Conduit.

• Embed it in a packaged build:

  meson setup _build -Dslack_client_id=1234567890.1234567890123

Choose Connect Workspace, approve access in the browser, and return to Conduit. If scopes change later, sign out, update the Slack app, and reconnect so Slack issues a new grant.

Desktop PKCE uses oauth.v2.user.access and user scopes. Conduit does not require a client secret or bot token for its core workspace connection.

Advanced: import a browser session

Conduit can import xoxc-* and xoxd-* browser-session credentials. Enable Use XOXC/XOXD tokens on the connection screen, or set:

export CONDUIT_SLACK_XOXC_TOKEN=xoxc-...
export CONDUIT_SLACK_XOXD_TOKEN=xoxd-...
export CONDUIT_SLACK_USER_AGENT="Mozilla/5.0 ..." # exact source-browser value for Enterprise Slack

The aliases SLACK_MCP_XOXC_TOKEN, SLACK_MCP_XOXD_TOKEN, and SLACK_MCP_USER_AGENT are also accepted.

Slack documents status changes through users.profile.set for OAuth user tokens. Imported browser-session credentials reuse Conduit's existing request transport, but Slack does not document that credential mode for Web API status changes. Use OAuth if Slack rejects the request.

Lookup SLACK_MCP_XOXC_TOKEN

• Open your browser's Developer Console.
• In Firefox, under Tools -> Browser Tools -> Web Developer tools in the menu bar
• In Chrome, click the "three dots" button to the right of the URL Bar, then select More Tools -> Developer Tools
• Switch to the console tab.
• Type "allow pasting" and press ENTER.
• Paste the following snippet and press ENTER to execute: JSON.parse(localStorage.localConfig_v2).teams[document.location.pathname.match(/^\/client\/([A-Z0-9]+)/)[1]].token

Token value is printed right after the executed command (it starts with xoxc-), save it somewhere for now.

Lookup SLACK_MCP_XOXD_TOKEN

• Switch to "Application" tab and select "Cookies" in the left navigation pane (or use a cookie manager extension).
• Find the cookie with the name d. That's right, just the letter d.
• Double-click the Value of this cookie.
• Press Ctrl+C or Cmd+C to copy it's value to clipboard.
• Save it for later.

User agent

For Enterprise Slack, copy navigator.userAgent from the same signed-in browser where you obtained the xoxc token and xoxd cookie. The upstream Slack MCP guidance notes that some higher-security environments additionally require a browser-compatible TLS handshake. Conduit does not impersonate a browser TLS fingerprint; if the exact User-Agent is still rejected, use the supported OAuth flow instead.

Browser-session credentials are highly sensitive and rely on an unofficial authentication path. Keep them out of shell history, logs, commits, screenshots, and issue reports. Unset the variables after import if you do not want Conduit to import them again after sign-out.

An imported browser session also supplies realtime updates through Slack's browser WebSocket. No xapp- token is needed for that workspace; Preferences → Realtime updates shows whether the XOXC/XOXD connection is online or retrying.

At startup, browser sessions also use Slack Web's private bootstrap/counts flow to establish unread conversation state. Slack does not document this flow as a supported API, so Conduit validates it defensively and falls back to its bounded per-conversation refresh if it is unavailable or changes shape.

Optional realtime updates

Enable Socket Mode in your Slack app, create an app-level token with connections:write, and subscribe to the message, reaction, and conversation events you want Conduit to receive. Save the xapp- token under Preferences → Realtime updates, then restart Conduit. The token is stored in the system keyring.

For development, the token can instead be supplied through the environment:

export CONDUIT_SLACK_APP_TOKEN=xapp-...

SLACK_APP_TOKEN is accepted as an alias. Environment values take precedence over the keyring. Socket Mode starts after OAuth authentication, stops on sign-out, and reconnects automatically after transient failures. Browser-session workspaces use their XOXC/XOXD WebSocket instead.

By default, incoming direct and group-direct messages, direct mentions, configured names/aliases or keywords/phrases, and replies in threads you started, replied to, or subscribed to can produce ten-second desktop notifications. Ordinary channel posts still become unread without notifying. Membership noise, other non-message noise, and self-authored messages become neither unread nor notifications. Muted or actively viewed messages do not notify but may remain unread; historical, already-observed, or at-or-before-read-cursor deliveries do not create new attention. Preferences → Notifications changes enabled triggers and configured terms immediately without a restart or reconnect.

Names, aliases, keywords, and phrases are entered one per line. Matching is case- and diacritic-insensitive, collapses whitespace, respects alphanumeric word boundaries, and keeps punctuation significant. Channel notifications include the resolved sender, and selecting a thread-reply notification opens the matching thread. See Attention And Notifications for the complete policy and raw-unread distinction. Without a realtime connection, Conduit continues to work through cached state, explicit refreshes, and Slack Web API requests.

Keyboard shortcuts

Action	Shortcut
Switch conversation	Ctrl+K
Search workspace messages	Ctrl+F
Messages / Unreads / Files / Later	Ctrl+1 / Ctrl+2 / Ctrl+3 / Ctrl+4
Focus composer	Ctrl+M
Send message	Enter
Insert newline	Shift+Enter or Ctrl+Enter
Complete emoji	Type : and at least two characters, then Enter or Tab
Complete person	Type @, filter by name, then Enter or Tab
Upload file	Ctrl+O
Close thread	Ctrl+Shift+W
Refresh conversations	F5
Show shortcuts	Ctrl+?
Preferences	Ctrl+,
Quit	Ctrl+Q

Command-line options

-c, --connect       Open the workspace connection flow
-d, --debug         Enable UI, rendering, cache, and Slack diagnostics
    --debug-auth    Enable OAuth diagnostics only

Debug output can contain private workspace metadata such as channel names, user IDs, timestamps, and unread counts. To opt into only the attention diagnostics target, run:

RUST_LOG=conduit::attention=trace conduit

That target is limited to counters, booleans, and stable category codes; it excludes message text, configured terms, and workspace, user, conversation, and message identifiers. This target-specific privacy property does not apply to general --debug output. Diagnostics should not contain tokens or authorization codes, but always review and redact logs before sharing them.

Local data and security

• OAuth tokens, imported browser-session credentials, and Socket Mode app tokens are stored through the system Secret Service/keyring.
• Workspace metadata, resolved names and statuses, emoji information, and message and thread history are stored in state/state.sqlite3 below Conduit's XDG cache directory. Downloaded attachments, image/media data, and WebKit data are cached in sibling directories. None has additional application-level encryption.
• Drafts and preferences are stored through GSettings.
• Huddle media, portal sessions, SDP, ICE candidates, and TURN credentials are ephemeral and are not stored in Conduit's cache or settings.
• Sign Out removes the keyring credential and deactivates the workspace for desktop search. It does not currently erase cached workspace content or drafts, and credential environment variables remain available for re-import.
• Authenticated preview, media, and attachment downloads accept only trusted Slack HTTPS URLs and enforce size bounds. Conduit also restricts message navigation to supported internal actions and HTTP(S) links and disables file-URL access and several unused WebKit capabilities. This is not a claim of a formal security audit.

Never share tokens, cookies, private messages, or unredacted debug logs. See SECURITY.md for vulnerability-reporting guidance.

Troubleshooting

• If a feature reports missing permissions, sign out, update the Slack app's user scopes, and reconnect to obtain a fresh grant.
• If a development build cannot find conduit.gresource, run it from the Meson build tree or set CONDUIT_RESOURCE_PATH to the generated resource bundle.
• If credentials cannot be stored, confirm that a Secret Service-compatible keyring is installed and unlocked.
• If realtime updates are absent, check Preferences → Realtime updates. For OAuth workspaces, verify Socket Mode, event subscriptions, and the xapp- token. For browser-session workspaces, re-import valid XOXC/XOXD credentials. Core Web API workflows remain available without realtime updates.
• If a slack:// link opens another client, check xdg-mime query default x-scheme-handler/slack, install Conduit's desktop entry, and select it as described above. Browser external-protocol prompts may need separate approval.
• If huddle discovery is available but native joining is not, use Open in Slack. This is the expected safe fallback until Conduit has both a verified Slack bootstrap adapter and a compatible Amazon Chime bridge.
• Use --debug-auth for OAuth problems and --debug for wider diagnostics, then redact output before sharing it.

Project direction

The near-term goal is a dependable, keyboard-friendly client for daily channel, DM, thread, unread, reaction, search, saved-item, and file workflows. Broader Slack surface parity will follow where public APIs and a native desktop experience make it practical.

Contributions are welcome. Read CONTRIBUTING.md before starting larger work, and use the guidance in SECURITY.md for sensitive reports. The project is licensed under GPL-3.0-or-later.