Slack Messaging: Install, Source and Security | FunnelSlayer
FunnelSlayer
Book a call

Slack Messaging

Published by obra in superpowers-lab

Review recommended223 installs

What this skill does

Use when asked to send or read Slack messages, check Slack channels, test Slack integrations, or interact with a Slack workspace from the command line.

Add Slack Messaging to your agent

Review the source and files first. When you are ready, copy the prompt instruction or use the CLI command supported by your environment.

Install with a prompt

Paste this into a compatible coding agent:

add this skill "slack-messaging" from https://github.com/obra/superpowers-lab

Install with the CLI

Run this command in a controlled environment after reviewing the repository:

npx skills add https://github.com/obra/superpowers-lab --skill slack-messaging

Skill instructions

Slack Messaging via slackcli

Send and read Slack messages from the command line using slackcli (shaharia-lab/slackcli).

Installation

Download the binary:

curl -sL -o /usr/local/bin/slackcli \
  "https://github.com/shaharia-lab/slackcli/releases/download/v0.1.1/slackcli-linux"
chmod +x /usr/local/bin/slackcli

macOS (Intel): replace slackcli-linux with slackcli-macos macOS (Apple Silicon): replace with slackcli-macos-arm64

Authentication

slackcli uses browser session tokens (xoxc + xoxd) - no Slack app creation required.

Interactive Setup

./scripts/extract-tokens <workspace-url>

This walks the user through extracting tokens from browser DevTools.

Manual Setup

slackcli auth login-browser \
  --xoxd="xoxd-..." \
  --xoxc="xoxc-..." \
  --workspace-url=https://your-workspace.slack.com

Verify Auth

slackcli auth list

Finding Channels

Use slackcli conversations list to discover channels and their IDs:

# List all channels
slackcli conversations list

# Filter output
slackcli conversations list | grep -i "channel-name"

Sending Messages

# Send to a channel (use channel ID from conversations list)
slackcli messages send --recipient-id=C0XXXXXXXX --message="Hello from CLI"

# Send to a DM (use user's DM channel ID)
slackcli messages send --recipient-id=D0XXXXXXXX --message="Hey"

# Reply in a thread
slackcli messages send --recipient-id=C0XXXXXXXX --message="Thread reply" --thread-ts=1769756026.624319

The --recipient-id is always a channel ID (C...) or DM channel ID (D...).

Reading Messages

# Read last N messages from a channel
slackcli conversations read C0XXXXXXXX --limit=10

# Read as JSON (for parsing)
slackcli conversations read C0XXXXXXXX --limit=10 --json

# Read a thread
slackcli conversations read C0XXXXXXXX --thread-ts=1769756026.624319

Listing Channels

slackcli conversations list

Returns all public channels, private channels, and DMs with their IDs.

Testing Slack Integrations

To verify a bot or integration posted a message correctly:

# Read the channel, check for the expected message
slackcli conversations read CHANNEL_ID --limit=5 --json | jq '.messages[] | select(.text | contains("expected text"))'

To send a test message and verify the round-trip:

# Send
slackcli messages send --recipient-id=CHANNEL_ID --message="integration test $(date +%s)"

# Read back
slackcli conversations read CHANNEL_ID --limit=1 --json

Multiple Workspaces

slackcli supports multiple workspaces. Run the auth flow for each workspace you need:

# Add first workspace
./scripts/extract-tokens https://workspace-one.slack.com

# Add second workspace
./scripts/extract-tokens https://workspace-two.slack.com

# List all authenticated workspaces
slackcli auth list

When sending messages, slackcli automatically routes to the correct workspace based on the channel ID.

Token Notes

  • Browser tokens (xoxc/xoxd) act as the logged-in user, not a bot
  • Messages sent appear as the user, not an app
  • Tokens expire when the user logs out of the browser session
  • To refresh: re-extract tokens from a logged-in browser session
  • All workspace credentials are stored at ~/.config/slackcli/workspaces.json

Files included

  • scripts/extract-tokens
  • SKILL.md

More skills