Slack

Read Slack channels, messages, threads, users, files and bookmarks; post, update and schedule messages, react, create channels and canvases.

Notify teams in the channels they already use and feed conversation data into operational flows.

Build a flow with Slack Provider API documentation

Source actions

Destination actions

Data types

Validation status

Implemented · fixture tested.

Implementation is checked against provider-shaped fixtures for every action, authentication failures, rate limits, pagination and duplicate safety. Provider sandbox and authorised account validation are recorded separately when credential-backed runs are completed.

What you can map

auth

Check bot identity
Source
Workspace and bot identity for the token (auth.test).

bookmarks

Add channel bookmark
Destination
Not retried automatically
Adds a link bookmark to a channel.
List channel bookmarks
Source
Bookmarks pinned to a channel's header.

canvases

Create canvas
Destination
Not retried automatically
Creates a canvas from markdown, optionally attached to a channel.
Replace canvas content
Destination
Duplicate protected
Replaces the entire canvas content with new markdown (canvases.edit replace).

conversation members

Invite users to channel
Destination
Duplicate protected
Invites up to 100 users to a channel.
List channel members
Source
User IDs of the members of a channel.

conversations

Create channel
Destination
Duplicate protected
Creates a public or private channel. Channel names are unique per workspace.
Get channel
Source
Channel details including topic, purpose and member count.
List channels and conversations
Source
Public and private channels, DMs and group DMs visible to the bot.

direct messages

Open direct message
Destination
Duplicate protected
Opens (or returns the existing) direct or group DM with users; post to the returned channel ID.

ephemeral messages

Post ephemeral message
Destination
Not retried automatically
Posts a message only one user in the channel can see.

files

List files
Source
Incremental
File metadata, optionally filtered by channel, user, type and time.

messages

List channel messages
Source
Incremental
Channel history, newest first, optionally bounded by time.
Post message
Destination
Not retried automatically
Posts a message to a channel or DM, optionally as a thread reply.
Update message
Destination
Duplicate protected
Edits a message the app posted, identified by channel and timestamp.

reactions

Add reaction
Destination
Duplicate protected
Adds an emoji reaction to a message.

scheduled messages

Schedule message
Destination
Not retried automatically
Schedules a message for delivery up to 120 days ahead.

thread replies

List thread replies
Source
The parent message and replies of a thread.

user groups

List user groups
Source
User groups (handles) with member IDs.

users

Get user
Source
One user by ID.
List users
Source
Workspace members including bots and deactivated users.
Find user by email
Source
Looks up a member by email address (users.lookupByEmail).

Authentication

Bot user OAuth token (xoxb-)

Plans and access

All Slack plans, including Free (Free workspaces only show 90 days of history). A bot token only sees channels the app is a member of; private channels and DMs need the app to be invited. Workspace admins may need to approve the app.

Test environment

Use a free workspace or a Slack developer sandbox from the Slack Developer Program.

Rate limits

Per-method tiers (Tier 1: 1+/min to Tier 4: 100+/min); chat.postMessage allows about one message per second per channel. HTTP 429 with Retry-After. Non-Marketplace apps created after May 2025 are limited to 1 request/min and 15 messages for conversations.history and conversations.replies.

Provider events

Events API (message, reaction, channel and user events). Nexra event triggers are not yet available; flows run on demand or on a schedule.

Before you build a flow

Slack has no idempotency key for chat.postMessage, chat.scheduleMessage, chat.postEphemeral, bookmarks.add or canvases.create; uncertain sends are not repeated automatically.
Message search (search.messages) requires a user token and is not implemented with the bot token.
File metadata is read; file contents are not downloaded or uploaded.
Deleting messages, channels, bookmarks and canvases, and archiving channels, are not implemented.
Slack returns most errors as HTTP 200 with ok:false; Nexra classifies the error code (invalid_auth, missing_scope, channel_not_found, ratelimited and others).