NoSlacking

A fast, native Slack and Microsoft Teams client for Linux, macOS and Windows.
One small window for all your workspaces. No Electron, no browser engine.

Why NoSlacking

• Native and light. Written in Rust on egui, with no browser engine inside: one small program instead of a copy of Chrome.
• Everything you do in Slack every day. Channels, DMs, threads, reactions, files, search, notifications and your sidebar sections, across all your workspaces.
• Teams in the same window. Your Microsoft Teams chats, channels, calls and meetings sit in the workspace rail beside your Slack workspaces.
• Built for the keyboard. Ctrl+K to jump anywhere, single keys for the selected message, and a sheet of every shortcut on Ctrl+/.
• Calm by default. Unread conversations rise to the top of their section; quiet ones tuck away behind "N more" until you need them.
• Your secrets stay put. Tokens and cookies live only in your operating system's keyring, never in a file or the log.
• Yours to tweak. Dark and light themes, your own palettes, a compact layout, and scripting hooks that run your programs on new messages.

Features

Links to Slack messages show as quotes	Search with Slack's own filters

Conversations

• Channels, private channels, direct and group messages, in one workspace rail across several workspaces, with your Slack sidebar sections.
• Unread conversations first, quiet ones behind "N more", and closed or empty group chats out of the way.
• Start DMs and group DMs with the + on Direct messages; browse, join, leave and create channels; channel details, pins and bookmarks you can add and edit.

Messages

• History that scrolls back smoothly, an unread line, and "jump to unread" and "jump to newest".
• Threads in a side panel, with "also send to the channel".
• Reactions with skin tones, your workspace's custom emoji (and adding new ones), inline images, file cards, highlighted code blocks and Slack's rich text, drawn just as Slack lays it out.
• Links to Slack messages shown as quotes, and app buttons you can press (with browser sign-in).
• Mark unread, save for later, share to another conversation, pin, copy a link, edit, delete, and delete your own files.

Huddles (with browser sign-in)

• Join, start, listen and talk in huddles right in the app, with echo cancellation and noise suppression, a call bar showing who is talking, and Leave and mute on keyboard shortcuts.
• Watch screen shares and cameras in a call window of its own, turn on your camera, and share your screen (through the desktop's own screen picker on Wayland).
• Choose the microphone, speaker and camera in Settings → Huddles, or switch them mid-call from the arrows beside Mute and Video.
• Huddle invitations as a card and a desktop notification.

Microsoft Teams (also in the same window)

• Chats, and your teams' channels as posts with replies, with mentions and formatting.
• Calls, and meetings joined by link or ID or started with Meet now, with cameras, screen sharing and admitting people from the lobby.
• Reactions, editing and new messages, notifications, read state and presence, as for Slack.
• Not yet for Teams: search, files and uploads, pins, bookmarks, Later, scheduled messages, your status and Do Not Disturb, custom emoji, and browsing or creating channels. Closing a chat hides it here only.
• Add a Teams account (work, school or personal) from the sign-in screen; see Signing in and Use at your own risk before using it at work.

Writing

• @mention, @group, #channel and :emoji: autocomplete, slash commands, formatting shortcuts, Shift+Enter for a new line, and spell checking.
• Drafts kept across restarts, Send later, and pasting images or files to upload them.
• Web addresses you type become links, for everyone reading them.

Staying in the loop

• Notifications for DMs, mentions and your own keywords, with mute, per-conversation levels and Do Not Disturb; they still arrive when the live connection drops.
• Activity, All unreads, Threads, Later and Scheduled views, and search over messages and files with from:, in:, before: and has:.
• Presence and typing, your status, and "always show as active".

On your desktop

• A tray icon that keeps you connected when the window is closed, the unread count in the title and launcher, and start at login.
• Themes (dark, light, your own palettes, and Omarchy on Linux) and a compact layout.
• Keyboard navigation, screen reader labels, and an English and Dutch interface.

Installing

Every release has:

System	Download
Debian, Ubuntu	.deb
Fedora, openSUSE	.rpm
Any Linux	.flatpak (install with flatpak install --user <file>) or .tar.gz
macOS	.zip with the app
Windows	.zip with the program

Then start NoSlacking and sign in.

Signing in

Slack

• Sign in with your browser. NoSlacking opens Slack's sign-in page in your browser. Sign in as usual (password, emailed code or SSO); when Slack hands the sign-in back, the browser passes it to NoSlacking, which registers itself for slack:// links when you start this sign-in, and only for it: once the link has come, you cancel, 15 minutes pass or you quit, it gives them back to whatever had them before, such as the Slack app. If your browser does not pass it on, paste the slack:// link from the page instead. Nothing needs to be registered with Slack.
• Your own Slack app (advanced). Tucked away at the bottom of the sign-in screen: create a free Slack app from the bundled manifest, paste its credentials, and sign in. This is the route Slack documents and supports, with live Socket Mode updates; a workspace admin may need to approve the app.

The manifest is at version 2 (its description says "manifest v2"). Version 2 adds dnd:read, dnd:write, usergroups:read and bookmarks:write, for Do Not Disturb kept in step with Slack, @group suggestions and editing bookmarks. An app made from the first manifest still signs in: if Slack refuses the newer permissions, NoSlacking asks again for the ones the app has, and those features stay off for that workspace. Settings → Workspaces then says what is missing. To update the app, copy the new manifest there, open your app on api.slack.com/apps, paste it under App Manifest and save, reinstall the app when Slack asks, and press Sign in again.

Browser sign-ins get live messages over Slack's session socket. Tokens and cookies are stored only in your operating system's keyring (Secret Service on Linux, the Keychain on macOS, the Credential Manager on Windows), never in a file, and never written to the log.

Microsoft Teams

On the sign-in screen (or + in the workspace rail), under Sign in to Microsoft Teams:

1. For a work or school account, leave Organization / Tenant empty, or fill in the company's domain (company.onmicrosoft.com) or tenant ID. A guest account needs the domain of the company that invited you. For a personal Teams (free) account, tick Personal account.
2. Press Sign in with Microsoft Teams. NoSlacking shows a code: copy it, press Open Microsoft Login, enter the code on Microsoft's page and sign in there as usual. NoSlacking finishes by itself.

NoSlacking signs in as Microsoft's own Teams app, the way other unofficial Teams clients do. No app needs registering, and your organisation's app approval does not apply to it, which is also why an administrator may see the sign-in as unusual or block it (see the research note). A personal account has chats but no teams or channels. Live messages come over Teams' own push connection, and the tokens are kept in the keyring, as Slack's are.

Building from source

cargo build --release
cargo run --release

You need a Rust toolchain, the egui build dependencies and, for huddles, OpenSSL's headers on Linux or Perl on macOS and Windows; see CONTRIBUTING.md. Video in huddles and calls comes from a small helper program, noslacking-video, that ships beside the app: cargo build --release builds both. It uses the GPU on Linux (VA-API) and works in software on macOS and Windows. To try the interface without a Slack account, run the demo:

cargo run --features demo

Scripting hooks

NoSlacking can run your own programs on new messages: to speak them aloud, log them, or light a lamp. Turn them on under Settings → Scripting hooks.

How hooks run, and the JSON they get

Hooks work in the spirit of wee-slack's. Each one names a program and what it runs for: mentions of you, direct messages, or keywords (comma separated, matched as whole words, ignoring case).

• The program runs directly, never through a shell. Its command line is split on spaces; put "…" or '…' around a part with spaces. There are no variables, pipes or globs.
• It gets one JSON object on its standard input and nothing on its command line. Its output is ignored.
• It may run for 10 seconds before it is stopped, and at most four hooks run at once; a message that arrives while four are running skips them.
• Only failures are logged (the program could not start, failed, or was stopped), never the message.
• The JSON never holds a token, a cookie or a file link that would need one.

Only new messages from other people run hooks, not edits, history or your own messages. A mention of you is checked first, then a direct message, then the keywords; the first that matches is the reason, and a hook runs once per message.

{
  "version": 1,
  "event": "message",
  "reason": "keyword",
  "keyword": "deploy",
  "workspace": { "id": "T0123", "name": "Acme", "domain": "acme" },
  "conversation": { "id": "C0456", "name": "engineering", "kind": "channel" },
  "message": {
    "ts": "1700000000.000100",
    "thread_ts": null,
    "user": "U0789",
    "author": "Ana",
    "text": "<@U0001> is the deploy done?",
    "plain": "@Yannick is the deploy done?"
  },
  "permalink": "https://acme.slack.com/archives/C0456/p1700000000000100"
}

• reason is mention, direct or keyword; keyword is only there for keyword, and names the one that matched.
• conversation.kind is channel, private, direct or group.
• message.text is Slack's own markup; message.plain is the same text with people and channels by name. thread_ts is the thread's parent for a reply, else null. user is null for some apps.
• permalink opens the message in Slack, or is null when there is none.
• version goes up only when the shape changes in a way a script would notice; new fields may appear at any time.

Files

NoSlacking keeps settings and themes in your config directory, logs and read state in your state directory, and the image cache in your cache directory. Open them from Settings → Files.

Use at your own risk

NoSlacking is an independent, unofficial client. It is not made, endorsed, supported or reviewed by Slack Technologies, Salesforce or Microsoft. "Slack" is a trademark of Salesforce, Inc., and "Microsoft Teams" a trademark of Microsoft Corporation, used here only to say which services this client works with.

Before you use it, know that:

• Browser sign-in is unsupported. It uses endpoints that Slack does not document. Slack can change or remove them at any time, and NoSlacking may stop working without warning.
• It may break your workspace's rules or Slack's terms. Slack's terms limit third-party clients, and your workspace may only allow approved apps. Slack or a workspace admin may sign out or suspend an account that uses an unofficial client. Check with your workspace's admins if you are unsure, and do not use it where it is not allowed.
• Your session is as powerful as your password. The d cookie and the session tokens give full access to your account. NoSlacking keeps them in the OS keyring and sends them only to Slack's own hosts, but treat them like a password and sign out (or revoke the session in Slack) on a computer you stop using.
• Teams sign-in goes around your organisation's app controls. It signs in as Microsoft's own Teams app, on endpoints Microsoft does not document for others. Administrators may see it as an unusual sign-in, Conditional Access may block it, and Microsoft's API terms forbid getting around technical limits. Do not use it at work without your administrators' agreement.
• There is no warranty. The software is provided as is; see the license.

Use NoSlacking only with your own accounts, and use your own Slack app (the documented route) where your workspace requires it.

Thanks

NoSlacking is built on egui and the fastframe crates, the same foundation as ZapFast and Spotifast.

NoSlacking owes its approach to two other unofficial clients:

• Make Slack Great Again (msga), which inspired session sign-in and signing in through the browser by catching Slack's hand-off.
• wee-slack, which has reused the browser session for years.

License

MIT; see LICENSE.