Slack integration

Overview

Slack is the de-facto team messaging platform. The Automize Slack connector covers messaging (channels, DMs, threads, scheduling), search, user / channel management, file uploads, and reactions – the operations you actually want when wiring Slack into an automation.

• Regions: Slack is a single global platform. Enterprise Grid customers have multiple workspaces under one Org – each workspace authenticates separately. The connector handles per-workspace connections.
• Plans: Free, Pro, Business+, Enterprise Grid all expose the same Web API. Some endpoints (Analytics, SCIM) need Plus/Enterprise.

Setting up the connection

Auth type: OAuth 2.0 (Authorization Code).

1. Sign in to api.slack.com/apps → Create New App → From scratch.
2. Under OAuth & Permissions, add scopes (see below) and set the Redirect URL to the one in the Automize Slack connector dialog.
3. Install the app to the workspace – copy the Bot User OAuth Token (xoxb-...) shown after install.
4. In Automize, open Settings → Connectors → Slack → Add connection. Use the OAuth flow if available, or paste the bot token directly.

Scopes required:

• chat:write
• channels:read
• channels:history
• groups:read
• groups:history
• im:write
• users:read
• users:read.email
• files:write
• search:read
• reactions:write

Find your credentials at https://api.slack.com/apps.

Rate limits

Slack rate limits per method tier – tier 1 (1/min, e.g. admin), tier 2 (20/min, e.g. conversations.history), tier 3 (50/min, e.g. chat.postMessage), tier 4 (100+/min, lightweight reads). The connector reads Retry-After headers and backs off. For bulk channel scans, page with limit=200.

Data model

Slack's primitives:

    Workspace ─┬─ Users (incl. bots, apps)
               ├─ Channels (public, private, MPIM, DM)
               ├─ Conversations (the unified term for any "place messages live")
               │      └─ Messages ─── Threads (parent message + replies)
               ├─ Files
               └─ Reactions

channel_id and user_id are unique within a workspace. Conversation IDs
start with C (channel), G (private group), D (DM), or MPIM-prefix.

Available operations

21 operations available. Click any row to jump to its detail.

Operations

Add reaction

Add an emoji reaction to a Slack message.

Tips

• channel + timestamp + name (emoji name without colons, e.g. 'thumbsup').

Archive channel

Archive a Slack channel.

Tips

• Archives the channel. Reversible via Slack UI (admin only).

Create channel

Create a new Slack channel.

Tips

• name: channel name (lowercase, no spaces, max 80 chars).
• is_private=true creates a private channel.

Delete message

Delete a Slack message.

Tips

• channel + ts. Bots can only delete their own messages.

Get channel history

Get message history for a Slack channel.

Get thread replies

Get replies in a Slack message thread.

Get user info

Get a Slack user's profile information.

Invite to channel

Invite user(s) to a Slack channel.

Tips

• users: comma-separated user IDs. Channel must already exist.

List channels

List public Slack channels in the workspace.

No input parameters.

Tips

• types: public_channel, private_channel, mpim, im (comma-separated).
• exclude_archived=true skips archived channels.

List users

List Slack workspace members.

No input parameters.

Tips

• All users in the workspace including bots, apps, deactivated.
• Filter client-side by deleted=false for active humans.

Open conversation

Open or create a DM or multi-party DM in Slack.

Pin message

Pin a message to a Slack channel.

Schedule message

Schedule a Slack message for later.

Tips

• post_at is a Unix timestamp. Returns scheduled_message_id which you can delete with Delete Scheduled Message.
• Max scheduling window: 120 days into the future.

Search messages

Search messages in the Slack workspace.

Tips

• query: same syntax as Slack's search box (from:@user in:#channel after:2026-01-01).
• Requires user token (xoxp-...), not bot token – bot tokens can't search.

Send message

Send a message to a Slack channel with optional threading and Block Kit formatting.

Tips

• channel: channel ID (C..., G..., D...) or @username for DM, or #channel-name (slower lookup).
• text: plain text, or use blocks for rich Block Kit layouts.
• thread_ts: if replying in a thread, pass the parent message's ts.

Errors

• not_in_channel – Bot user is not a member of the channel. Invite the bot via /invite @YourBot in Slack.
• channel_not_found – Channel doesn't exist or bot can't see it (private channels need explicit invite).

Set channel purpose

Set a Slack channel's purpose.

Set channel topic

Set a Slack channel's topic.

Unarchive channel

Unarchive a Slack channel.

Unpin message

Unpin a message from a Slack channel.

Update message

Update an existing Slack message.

Tips

• channel + ts (the message timestamp) identifies the message. Bots can only edit messages they sent.

Upload file

Upload a file to a Slack channel.

Tips

• channels (comma-separated channel IDs) + content (bytes) + filename.
• Returns the file ID and shareable URL.

FAQ

Why does my bot get 'not_in_channel' on a public channel?

Bots must be explicitly invited even to public channels. Type /invite @YourBot in the channel. Once added, future calls succeed.

Bot token vs User token – which?

Bot token (xoxb-) acts as the bot user. User token (xoxp-) acts as the installing user – needed for search.messages and some admin operations. Use bot for almost everything.

How do I DM a user?

Open a DM channel via conversations.open with user IDs, get back a channel ID, then Send Message to that channel. Or pass user_id directly to Send Message (we handle the open under the hood).

Can I post as a custom username/icon?

Yes via username + icon_emoji or icon_url on Send Message. Requires the chat:write.customize scope. Some workspaces disable this.

Related connectors

• Discord