slack-cli

Slack CLI

Interact with Slack workspaces from the command line using slack-cli and direct Slack API calls.

Assume slack-cli is already installed and configured. If the slack command is not found or returns not_inited, refer to references/INSTALLATION.md for setup instructions.

When to Use

• User wants to send, update, or delete Slack messages
• User wants to read channel history or search messages
• User wants to list channels, users, or conversations
• User wants to upload files to Slack
• User wants to manage reminders, snooze, or presence
• User wants to automate Slack workflows

Setup

If slack is not available or not configured, see references/INSTALLATION.md for full setup instructions.

The token is stored at the path configured in the slack binary's etcdir variable (typically /opt/homebrew/etc/slack-cli/.slack on macOS). You can also use the SLACK_CLI_TOKEN environment variable.

Credential Management with psst

Store the Slack token in the global psst vault:

psst --global set SLACK_CLI_TOKEN --tag slack

For built-in commands, inject the token via psst:

psst --global SLACK_CLI_TOKEN -- slack chat send 'Hello!' '#channel'

For direct API calls, use inline psst get:

Built-in Commands

The slack CLI supports these commands natively:

Chat

Files

Reminders

Snooze (Do Not Disturb)

Presence

Global Options

All commands support:

• --filter|-f <jq-filter> — Apply a jq filter to the JSON response
• --compact|-cp — Compact JSON output
• --monochrome|-m — No color in jq output
• --trace|-x — Enable bash trace for debugging

Known Limitations

• DMs via built-in CLI don't work reliably. slack chat send 'msg' '@user' often fails with channel_not_found. Use the direct API pattern below instead.
• Messages sent via chat:write appear as the Slack App, not as your user. This is a Slack API limitation — even with a user token, the app identity is used.

Direct API Calls

The slack CLI doesn't cover all Slack API methods. For anything beyond the built-in commands, call the Slack API directly using curl. Read the token from the CLI's config file.

Sending Direct Messages

The built-in slack chat send doesn't handle DMs well. Use the API directly:

Requires im:write scope. Without it, conversations.open will fail. If you don't have im:write, you can work around it by finding an existing DM channel:

DM_CHANNEL=$(curl -s \
  -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/conversations.list?types=im&limit=200" | \
  jq -r '.channels[] | select(.user == "USER_ID") | .id')

List Channels

curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/conversations.list?types=public_channel,private_channel&limit=200" | \
  jq '[.channels[] | {name, id, is_private}]'

Read Channel History

# Get recent messages from a channel (use channel ID)
curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/conversations.history?channel=CHANNEL_ID&limit=20" | \
  jq '[.messages[] | {user, text, ts}]'
 
# Get messages from last 7 days
OLDEST=$(date -v -7d +%s)
curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/conversations.history?channel=CHANNEL_ID&oldest=${OLDEST}&limit=100" | \
  jq '[.messages[] | {user, text, ts}]'
 
# Get messages within a specific date range (oldest and latest are unix timestamps)
curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/conversations.history?channel=CHANNEL_ID&oldest=${START_TS}&latest=${END_TS}&limit=100" | \
  jq '[.messages[] | {user, text, ts}]'

List Users

curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/users.list" | \
  jq '[.members[] | {name, id, real_name}]'
 
# Resolve multiple user IDs (no batch endpoint — fetch all and filter)
curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/users.list" | \
  jq '[.members[] | select(.id == "U1234" or .id == "U5678") | {id, name: .real_name}]'

Workspace Info

# Use auth.test (not team.info — team.info requires a scope we don't have)
curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/auth.test" | \
  jq '{team, team_id, url}'

Search Messages

curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/search.messages?query=keyword&count=10" | \
  jq '[.messages.matches[] | {channel: .channel.name, text, ts}]'

Reactions

# Add a reaction
curl -s -X POST \
  -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  -H "Content-Type: application/json" \
  -d '{"channel":"CHANNEL_ID","timestamp":"1234567890.123456","name":"thumbsup"}' \
  "https://slack.com/api/reactions.add"
 
# Get reactions on a message
curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/reactions.get?channel=CHANNEL_ID&timestamp=1234567890.123456"

Thread Replies

# Get replies in a thread (use the parent message ts)
curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  "https://slack.com/api/conversations.replies?channel=CHANNEL_ID&ts=1234567890.123456" | \
  jq '[.messages[] | {user, text, ts}]'

Post to a Thread

curl -s -X POST \
  -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" \
  -H "Content-Type: application/json" \
  -d '{"channel":"CHANNEL_ID","text":"reply text","thread_ts":"1234567890.123456"}' \
  "https://slack.com/api/chat.postMessage"

Tips

• Channel arguments accept #name format for built-in commands, but direct API calls require channel IDs (e.g. CHANNEL_ID)
• Use --filter with any built-in command to extract specific fields via jq
• Pipe commands together using --filter '.ts + "\n" + .channel' to chain send/update/delete
• For direct API calls, always quote the URL to prevent shell glob expansion
• Pagination: most list endpoints support cursor and limit parameters — check response_metadata.next_cursor in the response
• To look up a user ID by name: curl -s -H "Authorization: Bearer $(psst --global get SLACK_CLI_TOKEN)" "https://slack.com/api/users.list" | jq -r '.members[] | select(.real_name | test("Name"; "i")) | {name, id, real_name}'
• Message permalinks: https://<workspace>.slack.com/archives/<channel_id>/p<ts_without_dot> — remove the dot from the message timestamp (e.g. ts 1769935497.539749 becomes p1769935497539749)