agent-slack

Slack automation CLI for reading, searching, sending, and managing messages, channels, and files. Supports message operations: fetch single messages or threads, browse channel history, send/edit/delete messages, add/remove reactions, and draft rich-text messages in a browser editor Download attachments (snippets, images, files) automatically; search messages and files across channels with date and user filters Create channels, invite users (including external), open DMs or group DMs, and mark channels as read up to a specific message Fetch Slack canvases as markdown and look up user information; multi-workspace support with explicit workspace targeting to avoid ambiguity Auto-authentication via Slack Desktop, Chrome, or Firefox; manual token configuration available via environment variables

INSTALLATION
npx skills add https://github.com/stablyai/agent-slack --skill agent-slack
Run in your project or agent environment. Adjust flags if your CLI version differs.

SKILL.md

Slack automation with agent-slack

agent-slack is a CLI binary on $PATH. Invoke directly (e.g. agent-slack user list).

Installation

If agent-slack is not found on $PATH, install it:

  • curl -fsSL https://raw.githubusercontent.com/stablyai/agent-slack/main/install.sh | sh (recommended)
  • npm i -g agent-slack (requires Node >= 22.5)
  • nix run github:stablyai/agent-slack -- <args> (no install needed, prefix all commands)

CRITICAL: Bash command formatting rules

Claude Code's permission checker has security heuristics that force manual approval prompts. Avoid these patterns to keep commands auto-allowed. See: https://github.com/anthropics/claude-code/issues/34379

  • **No # anywhere in the command string.** Treated as a comment delimiter even inside quotes. Use bare channel names (general not #general). No # comments in inline scripts — use the Bash tool's description parameter instead.
  • **No '' (consecutive single quotes) or "" (consecutive double quotes).** Triggers "potential obfuscation" check. Avoid Python empty string literals like d.get('key', '') — use d.get('key') instead.
  • **Only | jq for filtering — no python3, no other commands.** python3 -c is not in the allow list and triggers prompts. jq with single-quote-only expressions (no " inside) is safe:
  • WRONG: agent-slack search ... | python3 -c "..." (not allowed)
  • WRONG: agent-slack search ... | jq '.a + "x"' (mixed quotes)
  • RIGHT: agent-slack search ... | jq '.a'
  • RIGHT: agent-slack search ... | jq '.messages[] | .ts'
  • **No || or &#x26;&#x26; chains.** Run multiple agent-slack commands as separate Bash tool calls.
  • **No file redirects (>, >>).** Process JSON output directly, don't write to files.

Quick start (auth)

Authentication is automatic on macOS and Windows (Slack Desktop first, then Chrome/Firefox fallbacks on macOS).

If credentials aren’t available, run one of:

  • Slack Desktop import (macOS/Windows):
agent-slack auth import-desktop

agent-slack auth test
  • Chrome fallback:
agent-slack auth import-chrome

agent-slack auth test
  • Firefox fallback:
agent-slack auth import-firefox

agent-slack auth test
  • Or set env vars (browser tokens; avoid pasting these into chat logs):
export SLACK_TOKEN="xoxc-..."

export SLACK_COOKIE_D="xoxd-..."

agent-slack auth test
  • Or set a standard token:
export SLACK_TOKEN="xoxb-..."  # or xoxp-...

agent-slack auth test

Check configured workspaces:

agent-slack auth whoami

Canonical workflow (given a Slack message URL)

  • Fetch a single message (plus thread summary, if any):
agent-slack message get "https://workspace.slack.com/archives/C123/p1700000000000000"
  • If you need the full thread:
agent-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):

agent-slack message list "general" --limit 20

agent-slack message list "C0123ABC" --limit 10

agent-slack message list "general" --with-reaction eyes --oldest "1770165109.000000" --limit 20

agent-slack message list "general" --without-reaction dart --oldest "1770165109.000000" --limit 20

agent-slack message list "general" --resolve-users

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 file metadata in JSON output (typically under message.files[] / files[]), including name when available and path for the local download. Failed message attachment downloads keep the attachment entry, preserve a local .download-error.txt path, and include message.files[].error for message get/list or messages[].files[].error for search messages|all; search files skips files whose download fails.

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.

agent-slack message draft "general"

agent-slack message draft "general" "initial text"

agent-slack message draft "https://workspace.slack.com/archives/C123/p1700000000000000"

Send, edit, delete, or react

agent-slack message send "https://workspace.slack.com/archives/C123/p1700000000000000" "I can take this."

agent-slack message send "alerts-staging" "here's the report" --attach ./report.md

agent-slack message edit "https://workspace.slack.com/archives/C123/p1700000000000000" "I can take this today."

agent-slack message delete "https://workspace.slack.com/archives/C123/p1700000000000000"

agent-slack message send "general" "Here's the plan:

- Step 1: do the thing

- Step 2: verify it worked

  - Sub-step: check logs"

agent-slack message react add "https://workspace.slack.com/archives/C123/p1700000000000000" "eyes"

agent-slack message react remove "https://workspace.slack.com/archives/C123/p1700000000000000" "eyes"

Channel mode for edit/delete requires --ts:

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

agent-slack message delete "general" --workspace "myteam" --ts "1770165109.628379"

Attach options for message send:

  • --attach <path> upload a local file (repeatable)
  • --blocks <path> send raw Block Kit blocks from a JSON file (or - for stdin). Enables headers, dividers, table blocks, and other structured layouts. Incompatible with --attach.

message send returns channel_id plus the posted ts and a permalink (for non-attachment sends). thread_ts appears only when replying in a thread.

Mentions: just write @U05BRPTKL6A, @here, @channel, or @everyone — the CLI converts them to real Slack mention tokens and escapes literal &#x26;/</> in your text. You don't need to wrap IDs yourself.

List channels + create/invite users

agent-slack channel list

agent-slack channel list --user "@alice" --limit 50

agent-slack channel list --all --limit 100

agent-slack channel new --name "incident-war-room"

agent-slack channel new --name "incident-leads" --private

agent-slack channel invite --channel "incident-war-room" --users "U01AAAA,@alice,bob@example.com"

agent-slack channel invite --channel "incident-war-room" --users "partner@vendor.com" --external

agent-slack channel invite --channel "incident-war-room" --users "partner@vendor.com" --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:

agent-slack search all "smoke tests failed" --channel "alerts" --after 2026-01-01 --before 2026-02-01

agent-slack search messages "stably test" --user "@alice" --channel general

agent-slack search messages "stably test" --resolve-users

agent-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 (e.g. general), pass --workspace (or set SLACK_WORKSPACE_URL) to avoid ambiguity:

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

agent-slack message get "general" --workspace "myteam" --ts "1770165109.628379"

DM / group DM channels

Get the channel ID for a DM or group DM, useful for sending messages to a group of users:

agent-slack user dm-open @alice @bob

agent-slack user dm-open U01AAAA U02BBBB U03CCCC

Mark as read

Mark a channel, DM, or group DM as read up to a given message:

agent-slack channel mark "https://workspace.slack.com/archives/C123/p1700000000000000"

agent-slack channel mark "general" --workspace "myteam" --ts "1770165109.628379"

agent-slack channel mark "D0A04PB2QBW" --workspace "myteam" --ts "1770165109.628379"

To make a specific message appear unread, set --ts to just before it (subtract 0.000001). This moves the read cursor so that message and everything after it appear as new:

agent-slack channel mark "general" --workspace "myteam" --ts "1770165109.628378"

Workflows

Discover and run Slack workflows bookmarked in channels:

# List workflows in a channel

agent-slack workflow list "#ops"

# Preview trigger metadata (no side effects)

agent-slack workflow preview "Ft123ABC"

# Get workflow definition including form fields and steps

agent-slack workflow get "Ft123ABC"

agent-slack workflow get "Wf456DEF"

# Trip a workflow trigger

agent-slack workflow run "Ft123ABC" --channel "#ops"

Later (saved messages)

Manage your saved-for-later messages:

agent-slack later list

agent-slack later list --counts-only

agent-slack later list --state completed

agent-slack later complete "<message-url>"

agent-slack later archive "<message-url>"

agent-slack later reopen "<message-url>"

agent-slack later save "<message-url>"

agent-slack later remove "<message-url>"

agent-slack later remind "<message-url>" --in 1h

agent-slack later remind "<message-url>" --in tomorrow

Unreads (inbox view)

See all unread messages across channels, DMs, and threads:

agent-slack unreads

agent-slack unreads --counts-only

agent-slack unreads --max-messages 5

agent-slack unreads --include-system

Canvas + Users

agent-slack canvas get "https://workspace.slack.com/docs/T123/F456"

agent-slack user list --workspace "https://workspace.slack.com" --limit 100

agent-slack user get "@alice" --workspace "https://workspace.slack.com"

References

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