slack

name

slack

description

Slack automation CLI for AI agents. Use when: - Reading a Slack message or thread (given a URL or channel+ts) - Browsing recent channel messages / channel history - Downloading Slack attachments (snippets, images, files) to local paths - Searching Slack messages or files - Sending, editing, or deleting a message; adding/removing reactions - Listing channels/conversations; creating channels and inviting users - Fetching a Slack canvas as markdown - Looking up Slack users Triggers: "slack message", "slack thread", "slack URL", "slack link", "read slack", "reply on slack", "search slack", "channel history", "recent messages", "channel messages", "latest messages"

Slack automation with slack

Use the bundled CLI launcher at ./.agents/skills/slack/bin/slack (or ./.bin/slack). The first invocation installs the latest upstream main CLI into this skill (.agents/skills/slack/vendor/agent-slack + .agents/skills/slack/bin/slack-cli).

./.agents/skills/slack/bin/slack user list

Quick start (auth)

Authentication is automatic on macOS (Slack Desktop first, then Chrome fallback).

If credentials aren’t available, run one of:

• Slack Desktop (default):

slack auth import-desktop
slack auth test

• Chrome fallback:

slack auth import-chrome
slack auth test

• Or set env vars (browser tokens; avoid pasting these into chat logs):

export SLACK_TOKEN="xoxc-..."
export SLACK_COOKIE_D="xoxd-..."
slack auth test

• Or set a standard token:

export SLACK_TOKEN="xoxb-..."  # or xoxp-...
slack auth test

Check configured workspaces:

slack auth whoami

Canonical workflow (given a Slack message URL)

1. Fetch a single message (plus thread summary, if any):

slack message get "https://workspace.slack.com/archives/C123/p1700000000000000"

2. If you need the full thread:

slack message list "https://workspace.slack.com/archives/C123/p1700000000000000"

Browse recent channel messages

To see what's been posted recently in a channel (channel history):

slack message list "#general" --limit 20
slack message list "C0123ABC" --limit 10
slack message list "#general" --with-reaction eyes --oldest "1770165109.000000" --limit 20
slack message list "#general" --without-reaction dart --oldest "1770165109.000000" --limit 20

This returns the most recent messages in chronological order. Use --limit to control how many (default 25). When using --with-reaction or --without-reaction, you must also pass --oldest to bound scanning.

Attachments (snippets/images/files)

message get/list and search auto-download attachments and include absolute paths in JSON output (typically under message.files[].path / files[].path).

Draft a message (browser editor)

Opens a Slack-like rich-text editor in the browser for composing messages with formatting toolbar (bold, italic, strikethrough, links, lists, quotes, code, code blocks). After sending, shows a "View in Slack" link.

slack message draft "#general"
slack message draft "#general" "initial text"
slack message draft "https://workspace.slack.com/archives/C123/p1700000000000000"

Send, edit, delete, or react

slack message send "https://workspace.slack.com/archives/C123/p1700000000000000" "I can take this."
slack message edit "https://workspace.slack.com/archives/C123/p1700000000000000" "I can take this today."
slack message delete "https://workspace.slack.com/archives/C123/p1700000000000000"
slack message react add "https://workspace.slack.com/archives/C123/p1700000000000000" "eyes"
slack message react remove "https://workspace.slack.com/archives/C123/p1700000000000000" "eyes"

Channel mode for edit/delete requires --ts:

slack message edit "#general" "Updated text" --workspace "myteam" --ts "1770165109.628379"
slack message delete "#general" --workspace "myteam" --ts "1770165109.628379"

List channels + create/invite users

slack channel list
slack channel list --user "@alice" --limit 50
slack channel list --all --limit 100
slack channel new --name "incident-war-room"
slack channel new --name "incident-leads" --private
slack channel invite --channel "incident-war-room" --users "U01AAAA,@alice,[e-mail]"
slack channel invite --channel "incident-war-room" --users "[e-mail]" --external
slack channel invite --channel "incident-war-room" --users "[e-mail]" --external --allow-external-user-invites

For --external, invite targets must be emails. By default, invitees are external-limited; add --allow-external-user-invites to allow them to invite other users.

Search (messages + files)

Prefer channel-scoped search for reliability:

slack search all "smoke tests failed" --channel "#alerts" --after 2026-01-01 --before 2026-02-01
slack search messages "stably test" --user "@alice" --channel general
slack search files "testing" --content-type snippet --limit 10

Multi-workspace guardrail (important)

If you have multiple workspaces configured and you use a channel name (#general / general), pass --workspace (or set SLACK_WORKSPACE_URL) to avoid ambiguity:

slack message get "#general" --workspace "https://myteam.slack.com" --ts "1770165109.628379"
slack message get "#general" --workspace "myteam" --ts "1770165109.628379"

Canvas + Users

slack canvas get "https://workspace.slack.com/docs/T123/F456"
slack user list --workspace "https://workspace.slack.com" --limit 100
slack user get "@alice" --workspace "https://workspace.slack.com"

References

• references/commands.md: full command map + all flags
• references/targets.md: URL vs #channel targeting rules
• references/output.md: JSON output shapes + download paths