Slack

Troubleshooting

If requests fail, run zero doctor check-connector --env-name SLACK_TOKEN or zero doctor check-connector --url https://slack.com/api/chat.postMessage --method POST

Messages

Send Message

curl -s -X POST "https://slack.com/api/chat.postMessage" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"text\": \"Hello, World\"}"

Send with Block Kit

curl -s -X POST "https://slack.com/api/chat.postMessage" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"text\": \"Fallback text\", \"blocks\": [{\"type\": \"section\", \"text\": {\"type\": \"mrkdwn\", \"text\": \"*Alert:* Something happened\"}}, {\"type\": \"section\", \"fields\": [{\"type\": \"mrkdwn\", \"text\": \"*Status:*\\nActive\"}, {\"type\": \"mrkdwn\", \"text\": \"*Priority:*\\nHigh\"}]}]}"

Block Kit Builder: https://app.slack.com/block-kit-builder

Reply in Thread

curl -s -X POST "https://slack.com/api/chat.postMessage" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"thread_ts\": \"<message-ts>\", \"text\": \"Thread reply\"}"

Update Message

curl -s -X POST "https://slack.com/api/chat.update" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"ts\": \"<message-ts>\", \"text\": \"Updated message\"}"

Delete Message

curl -s -X POST "https://slack.com/api/chat.delete" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"ts\": \"<message-ts>\"}"

Schedule Message

curl -s -X POST "https://slack.com/api/chat.scheduleMessage" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"text\": \"Scheduled message\", \"post_at\": 1735689600}"

post_at is a Unix timestamp. Must be within 120 days.

List Scheduled Messages

curl -s -X POST "https://slack.com/api/chat.scheduledMessages.list" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\"}"

Delete Scheduled Message

curl -s -X POST "https://slack.com/api/chat.deleteScheduledMessage" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"scheduled_message_id\": \"<scheduled-id>\"}"

Send Ephemeral Message

Only visible to the specified user.

curl -s -X POST "https://slack.com/api/chat.postEphemeral" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"user\": \"<user-id>\", \"text\": \"Only you can see this\"}"

Get Permalink

curl -s "https://slack.com/api/chat.getPermalink?channel=<channel-id>&message_ts=<message-ts>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Channels (Conversations)

Slack uses a unified "conversations" API for public channels, private channels, DMs, and group DMs.

List Channels

curl -s "https://slack.com/api/conversations.list?types=public_channel&limit=100" \
  --header "Authorization: Bearer $SLACK_TOKEN"

types: public_channel, private_channel, mpim (group DM), im (DM). Comma-separated for multiple.

Get Channel Info

curl -s "https://slack.com/api/conversations.info?channel=<channel-id>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Get Channel History

curl -s "https://slack.com/api/conversations.history?channel=<channel-id>&limit=20" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Params: latest, oldest (Unix timestamps), inclusive, limit (max 1000), cursor.

Get Thread Replies

curl -s "https://slack.com/api/conversations.replies?channel=<channel-id>&ts=<thread-ts>&limit=50" \
  --header "Authorization: Bearer $SLACK_TOKEN"

List Channel Members

curl -s "https://slack.com/api/conversations.members?channel=<channel-id>&limit=100" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Create Channel

curl -s -X POST "https://slack.com/api/conversations.create" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"name\": \"project-updates\", \"is_private\": false}"

Invite Users to Channel

curl -s -X POST "https://slack.com/api/conversations.invite" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"users\": \"<user-id-1>,<user-id-2>\"}"

Remove User from Channel

curl -s -X POST "https://slack.com/api/conversations.kick" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"user\": \"<user-id>\"}"

Join Channel

curl -s -X POST "https://slack.com/api/conversations.join" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\"}"

Leave Channel

curl -s -X POST "https://slack.com/api/conversations.leave" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\"}"

Set Channel Topic

curl -s -X POST "https://slack.com/api/conversations.setTopic" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"topic\": \"New topic text\"}"

Set Channel Purpose

curl -s -X POST "https://slack.com/api/conversations.setPurpose" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"purpose\": \"Channel purpose text\"}"

Rename Channel

curl -s -X POST "https://slack.com/api/conversations.rename" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"name\": \"new-channel-name\"}"

Archive Channel

curl -s -X POST "https://slack.com/api/conversations.archive" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\"}"

Unarchive Channel

curl -s -X POST "https://slack.com/api/conversations.unarchive" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\"}"

Mark Channel as Read

curl -s -X POST "https://slack.com/api/conversations.mark" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"ts\": \"<message-ts>\"}"

Open DM

curl -s -X POST "https://slack.com/api/conversations.open" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"users\": \"<user-id>\"}"

Returns a channel ID for the DM. Use multiple comma-separated user IDs for group DM.

Users

List Users

curl -s "https://slack.com/api/users.list?limit=100" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Get User Info

curl -s "https://slack.com/api/users.info?user=<user-id>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Look Up User by Email

curl -s "https://slack.com/api/users.lookupByEmail?email=<user-email>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Get User Profile

curl -s "https://slack.com/api/users.profile.get?user=<user-id>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Set User Profile

curl -s -X POST "https://slack.com/api/users.profile.set" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"profile\": {\"status_text\": \"On vacation\", \"status_emoji\": \":palm_tree:\", \"status_expiration\": 0}}"

Set Presence

curl -s -X POST "https://slack.com/api/users.setPresence" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"presence\": \"away\"}"

Values: auto, away.

List User's Channels

curl -s "https://slack.com/api/users.conversations?user=<user-id>&types=public_channel,private_channel&limit=100" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Search

Search Messages

curl -s "https://slack.com/api/search.messages?query=budget%20report&count=20&sort=timestamp" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Params: query (supports Slack search modifiers like from:@user, in:#channel, before:2026-04-01), count (max 100), sort (score or timestamp), sort_dir (asc or desc).

Search Files

curl -s "https://slack.com/api/search.files?query=presentation&count=20" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Search All

curl -s "https://slack.com/api/search.all?query=project%20update&count=20" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Files

Upload File

Step 1: Get upload URL.

curl -s -X POST "https://slack.com/api/files.getUploadURLExternal" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"filename\": \"report.pdf\", \"length\": 12345}"

Step 2: Upload to the returned URL, then call files.completeUploadExternal with the file_id.

curl -s -X POST "https://slack.com/api/files.completeUploadExternal" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"files\": [{\"id\": \"<file-id>\", \"title\": \"Report\"}], \"channel_id\": \"<channel-id>\"}"

Legacy Upload (Simpler)

curl -s -X POST "https://slack.com/api/files.upload" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  -F "channels=<channel-id>" \
  -F "file=@/path/to/file.txt" \
  -F "title=My File"

Note: files.upload is deprecated but still functional. For new integrations, use the two-step getUploadURLExternal + completeUploadExternal flow.

List Files

curl -s "https://slack.com/api/files.list?channel=<channel-id>&count=20" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Get File Info

curl -s "https://slack.com/api/files.info?file=<file-id>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Delete File

curl -s -X POST "https://slack.com/api/files.delete" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"file\": \"<file-id>\"}"

Reactions

Add Reaction

curl -s -X POST "https://slack.com/api/reactions.add" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"timestamp\": \"<message-ts>\", \"name\": \"thumbsup\"}"

Remove Reaction

curl -s -X POST "https://slack.com/api/reactions.remove" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"timestamp\": \"<message-ts>\", \"name\": \"thumbsup\"}"

Get Reactions on a Message

curl -s "https://slack.com/api/reactions.get?channel=<channel-id>&timestamp=<message-ts>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

List User's Reactions

curl -s "https://slack.com/api/reactions.list?user=<user-id>&count=20" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Pins

Pin a Message

curl -s -X POST "https://slack.com/api/pins.add" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"timestamp\": \"<message-ts>\"}"

Unpin a Message

curl -s -X POST "https://slack.com/api/pins.remove" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel\": \"<channel-id>\", \"timestamp\": \"<message-ts>\"}"

List Pins

curl -s "https://slack.com/api/pins.list?channel=<channel-id>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Bookmarks

List Bookmarks

curl -s -X POST "https://slack.com/api/bookmarks.list" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel_id\": \"<channel-id>\"}"

Add Bookmark

curl -s -X POST "https://slack.com/api/bookmarks.add" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel_id\": \"<channel-id>\", \"title\": \"Project Wiki\", \"type\": \"link\", \"link\": \"https://wiki.example.com\"}"

Remove Bookmark

curl -s -X POST "https://slack.com/api/bookmarks.remove" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"channel_id\": \"<channel-id>\", \"bookmark_id\": \"<bookmark-id>\"}"

User Groups

List User Groups

curl -s "https://slack.com/api/usergroups.list?include_users=true" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Create User Group

curl -s -X POST "https://slack.com/api/usergroups.create" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"name\": \"Engineering\", \"handle\": \"engineering\", \"description\": \"Engineering team\"}"

Update User Group Members

curl -s -X POST "https://slack.com/api/usergroups.users.update" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"usergroup\": \"<usergroup-id>\", \"users\": \"<user-id-1>,<user-id-2>\"}"

List User Group Members

curl -s "https://slack.com/api/usergroups.users.list?usergroup=<usergroup-id>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Reminders

List Reminders

curl -s "https://slack.com/api/reminders.list" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Add Reminder

curl -s -X POST "https://slack.com/api/reminders.add" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"text\": \"Review the PR\", \"time\": 1735689600}"

time is a Unix timestamp or natural language (e.g., in 15 minutes, tomorrow at 9am).

Complete Reminder

curl -s -X POST "https://slack.com/api/reminders.complete" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"reminder\": \"<reminder-id>\"}"

Delete Reminder

curl -s -X POST "https://slack.com/api/reminders.delete" \
  --header "Authorization: Bearer $SLACK_TOKEN" \
  --header "Content-Type: application/json" \
  -d "{\"reminder\": \"<reminder-id>\"}"

Do Not Disturb

Get DND Status

curl -s "https://slack.com/api/dnd.info?user=<user-id>" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Set Snooze

curl -s "https://slack.com/api/dnd.setSnooze?num_minutes=60" \
  --header "Authorization: Bearer $SLACK_TOKEN"

End DND

curl -s -X POST "https://slack.com/api/dnd.endDnd" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Emoji

List Custom Emoji

curl -s "https://slack.com/api/emoji.list" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Team Info

Get Workspace Info

curl -s "https://slack.com/api/team.info" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Get Team Profile Fields

curl -s "https://slack.com/api/team.profile.get" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Auth

Test Token

curl -s -X POST "https://slack.com/api/auth.test" \
  --header "Authorization: Bearer $SLACK_TOKEN"

Returns workspace, user, and bot info for the token. Useful for verifying connectivity and discovering the bot's user ID.

Guidelines

1. Channel IDs, not names: All API methods require channel IDs (e.g., C1234567890), not display names. Use conversations.list to discover IDs. 2. Message timestamps: Messages are identified by their ts (timestamp) field, not a numeric ID. Format: "1735689600.000100". 3. Pagination: Use cursor and limit params. Next page cursor is in response_metadata.next_cursor. Keep paginating until cursor is empty. 4. GET vs POST: Read methods (list, info, history) are typically GET with query params. Write methods (post, update, delete, create) are POST with JSON body. 5. Rate limits: Methods are grouped into tiers. Tier 1: 1/sec, Tier 2: 20/min, Tier 3: 50/min, Tier 4: 100+/min. Check Retry-After header on 429 responses. 6. Block Kit: Use blocks array for rich message formatting. Always include a text field as fallback for notifications. Builder: https://app.slack.com/block-kit-builder 7. Threading: Set thread_ts to reply in a thread. The parent message's ts is the thread_ts. 8. Conversation types: public_channel, private_channel, im (1:1 DM), mpim (group DM). Many methods accept a types param to filter. 9. User IDs: Users are identified by IDs like U1234567890. Use users.lookupByEmail to find a user by email. 10. File uploads: The legacy files.upload still works but is deprecated. Prefer the two-step flow: files.getUploadURLExternal → upload → files.completeUploadExternal.

Message Formatting

Admin API (Enterprise Grid Only)

The admin.* methods (100+ endpoints) are only available on Slack Enterprise Grid plans. They cover:

• admin.conversations — manage channels across an Enterprise org (create, archive, set teams, bulk move)
• admin.users — manage users across workspaces (assign, invite, remove, set admin/owner roles)
• admin.teams — manage workspaces (create, list, get settings)
• admin.apps — approve/restrict apps across the org
• admin.invites — manage workspace invite requests
• admin.roles — assign and list role-based access
• admin.usergroups — manage user groups across workspaces
• admin.barriers — manage information barriers
• admin.workflows — manage workflow builder workflows
• admin.analytics — access workspace analytics data
• admin.audit — access audit logs

Note: These methods require Enterprise Grid admin tokens with admin.* scopes. They will return missing_scope or not_allowed errors on non-Enterprise workspaces. See docs for details.

How to Look Up More API Details

• All Methods: https://docs.slack.dev/reference/methods
• Admin Methods: https://docs.slack.dev/reference/methods?filter=admin
• Scopes: https://docs.slack.dev/reference/scopes
• Block Kit Reference: https://docs.slack.dev/reference/block-kit
• Rate Limits: https://docs.slack.dev/apis/web-api/rate-limits
• Events API: https://docs.slack.dev/apis/events-api