slk

A blazingly fast Slack TUI. Keyboard-driven, beautifully themed, and under 20MB. One static binary. No Electron required.

Marketing site: getslk.sh · Docs: Wiki

slk is a daily-driver replacement for the official Slack desktop client, built in Go with bubbletea and lipgloss.

Why slk?

• Fast. Cold start in milliseconds. Render-cached messages. SQLite-backed scrollback. Real-time over WebSocket.
• Tiny. ~19 MB on disk. ~60 MB RSS for a live multi-workspace session vs. 500 MB–1.5 GB for the official client. No node_modules, no Chromium, no 1Gb RAM tax.
• Keyboard-first. Vim-style modal editing. j/k, h/l, i, Esc.
• Pretty. 36 built-in themes, lipgloss-styled panels, true-pixel avatars on kitty (half-block fallback elsewhere), emoji shortcodes, day separators, and pill-style reactions.
• Multi-workspace. All your workspaces stay connected in parallel. 1–9 to instantly jump between them, with live unread badges in the rail.
• Yours. TOML config, custom themes, custom channel sections via glob, XDG-compliant paths.

Highlights

• Real-time messages, edits, deletes, reactions, typing indicators
• Inline images (kitty graphics / sixel / half-block fallback) with full-screen preview
• Threads side panel + a workspace-wide threads view
• Smart paste: clipboard images, file paths, or text — multiple attachments + caption in one send
• Slack-native sidebar sections, kept live; or glob-based config sections
• Browser-cookie auth (xoxc + d) — no Slack App required
• Vim-style modal keybindings, fuzzy channel finder, workspace picker
• 36 themes + drop-in custom themes, live theme switcher
• OS desktop notifications on DMs, mentions, and configurable keywords

Full feature breakdown: [[Features|https://github.com/gammons/slk/wiki/Features]]

Quick install

Homebrew (macOS and Linux):

brew install gammons/tap/slk

Linux/macOS tarball (auto-resolves the latest version):

VERSION=$(curl -fsSL https://api.github.com/repos/gammons/slk/releases/latest | grep -oE '"tag_name": *"v[^"]+"' | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' | sed 's/^v//')
# Linux x86_64
curl -fsSL "https://github.com/gammons/slk/releases/latest/download/slk_${VERSION}_linux_x86_64.tar.gz" | tar xz
# macOS Apple Silicon
curl -fsSL "https://github.com/gammons/slk/releases/latest/download/slk_${VERSION}_darwin_arm64.tar.gz" | tar xz
sudo mv slk /usr/local/bin/

Go:

go install github.com/gammons/slk/cmd/slk@latest

For .deb / .rpm / .apk packages, Windows, build-from-source, and checksums, see the Installation wiki page.

Setup

slk uses your existing browser session. Grab your xoxc token and d cookie from DevTools, then:

slk --add-workspace

Full walkthrough: Setup wiki page.

Enterprise Grid

slk authenticates via the same xoxc browser session token and d cookie that app.slack.com uses. Every outbound request to *.slack.com is decorated with browser-like headers (User-Agent, Origin, Referer, Sec-Fetch-*) so Slack's anomaly detectors should treat the traffic the same way they treat the browser tab the token was extracted from.

This is best-effort mitigation, not a contract. Your IT policy may still flag slk regardless. If you're on Enterprise Grid and slk signs you out or triggers a security email after login, please file an issue with:

1. The exact email or notification text Slack sent.
2. Whether you got logged out of all sessions or only slk's.
3. The output of slk --version.

See #5 for history.

Inline images in tmux

If you run slk inside tmux on a Kitty-capable terminal (Kitty, Ghostty, WezTerm), images render natively as long as tmux passthrough is enabled:

set -g allow-passthrough on

Reload tmux for the setting to take effect (tmux kill-server, then reattach). Verify with:

tmux show -gv allow-passthrough

Expected output: on (or all).

If passthrough is off, slk detects this at startup and falls back to half-block rendering automatically — no config change needed. To force a specific renderer regardless of detection, set image_protocol in config.toml to kitty, sixel, halfblock, or off.

Unread indicator in tmux

slk sets the terminal window title to reflect unread state — for example slk SW (3) +1 means three channels-with-unreads in the active workspace and at least one other workspace also has unreads. The two-letter prefix is the active workspace's initials (matching the left-rail label).

Outside tmux this just works — modern terminals (Kitty, WezTerm, Alacritty, Ghostty, iTerm2, Windows Terminal, gnome-terminal) render title changes in their tab/window chrome.

Inside tmux there's an extra step. tmux intercepts the title escape from slk, and only re-emits it to the outer terminal when title forwarding is on, and it uses its own title template by default (#W = window name) rather than the pane's title. Add both lines to ~/.tmux.conf:

set -g set-titles on
set -g set-titles-string '#T'

#T (active pane title) is what carries slk's string. Reload tmux for the setting to take effect (tmux kill-server, then reattach). Verify with:

tmux show -gv set-titles
tmux show -gv set-titles-string

Expected output: on and #T.

If you'd prefer slk's unread indicator to work in tmux without any config change at all, that's tracked as a follow-up — it requires passing the title escape through tmux's DCS passthrough rather than relying on set-titles. Not in this release.

Debugging

Set SLK_DEBUG=1 to enable a comprehensive debug log written to slk-debug.log in the current working directory. The file is truncated each run, so reproduce the issue, quit slk, then copy the file before relaunching. Log lines are categorized ([cache], [imgfetch], [imgrender], [ws], [general]) so grep '\[cache\]' slk-debug.log slices to one focus area.

Documentation

Everything lives in the wiki:

• Installation — prebuilt binaries, Go install, build from source
• Setup — token extraction, adding workspaces
• Features — full feature breakdown
• Keybindings — every key, every mode
• Configuration — config.toml, custom themes, XDG paths
• Terminal Compatibility — what each terminal supports
• Clipboard and OSC 52 — copy/paste setup notes
• Tradeoffs and Non-Goals — roadmap, caveats, TOS notice
• Architecture — service layout, data layer

Disclaimer

slk is an independent, unofficial project. It is not affiliated with, endorsed by, or sponsored by Slack Technologies, LLC or Salesforce, Inc. "Slack" is a trademark of Slack Technologies, LLC; it is used here only to describe the service this client interoperates with.

slk talks to Slack via the same internal browser protocol the official web client uses. This is unofficial and not sanctioned by Slack — see Tradeoffs and Non-Goals for details.

License

MIT © Grant Ammons