Slack

Send messages, manage channels, and interact with Slack workspaces.

Detail	Value
Category	Communication
Base URL	https://slack.com/api
Authentication	Bearer Token
Endpoints	6
Connector key	slack

Using Slack in a workflow

1. Go to Connections and click New Connection.
2. Pick Slack from the marketplace.
3. Enter your credentials (see Authentication above for what's expected).
4. In a workflow, drop an API Call node and select this connection.
5. Pick the operation you need from the Operation dropdown — the full list is below.

Available endpoints

Endpoint	Summary
POST /chat.postMessage	Send a message to a channel
GET /conversations.list	List all channels
GET /conversations.history	Fetch channel message history
GET /users.list	List all users in workspace
GET /users.info	Get user profile info
POST /reactions.add	Add a reaction to a message

Each endpoint is documented in full below. Use the outline on the right to jump to one.

POST /chat.postMessage

Send a message to a channel

Detail	Value
Operation ID	messaging.postMessage
Method	POST
Path	/chat.postMessage

Parameters

No parameters.

Request Body

Field	Type
channel	string
text	string
blocks	array

Using this endpoint in a workflow

1. Add an API Call node to your workflow.
2. Pick your Slack connection from the Connection dropdown.
3. In the Operation dropdown, select messaging.postMessage.
4. Fill in the parameter fields that appear. Use {{...}} to reference upstream values.

Required fields are marked — fill them or the call will fail at runtime.

What it returns

The API Call node writes the response to the workflow context:

{
  status: 200,
  success: true,
  data: { ...response body from the API... },
  latencyMs: 142
}

Reference response fields downstream as {{nodeId.data.path}}. The exact response shape is documented on the upstream Slack API reference.

GET /conversations.list

List all channels

Detail	Value
Operation ID	messaging.listChannels
Method	GET
Path	/conversations.list

Parameters

Name	Location	Type	Required
types	query	string	No
limit	query	integer	No

Using this endpoint in a workflow

1. Add an API Call node to your workflow.
2. Pick your Slack connection from the Connection dropdown.
3. In the Operation dropdown, select messaging.listChannels.
4. Fill in the parameter fields that appear. Use {{...}} to reference upstream values.

What it returns

The API Call node writes the response to the workflow context:

{
  status: 200,
  success: true,
  data: { ...response body from the API... },
  latencyMs: 142
}

Reference response fields downstream as {{nodeId.data.path}}. The exact response shape is documented on the upstream Slack API reference.

GET /conversations.history

Fetch channel message history

Detail	Value
Operation ID	messaging.getHistory
Method	GET
Path	/conversations.history

Parameters

Name	Location	Type	Required
channel	query	string	Yes
limit	query	integer	No

Using this endpoint in a workflow

1. Add an API Call node to your workflow.
2. Pick your Slack connection from the Connection dropdown.
3. In the Operation dropdown, select messaging.getHistory.
4. Fill in the parameter fields that appear. Use {{...}} to reference upstream values.

Required fields are marked — fill them or the call will fail at runtime.

What it returns

The API Call node writes the response to the workflow context:

{
  status: 200,
  success: true,
  data: { ...response body from the API... },
  latencyMs: 142
}

Reference response fields downstream as {{nodeId.data.path}}. The exact response shape is documented on the upstream Slack API reference.

GET /users.list

List all users in workspace

Detail	Value
Operation ID	messaging.listUsers
Method	GET
Path	/users.list

Parameters

Name	Location	Type	Required
limit	query	integer	No

Using this endpoint in a workflow

1. Add an API Call node to your workflow.
2. Pick your Slack connection from the Connection dropdown.
3. In the Operation dropdown, select messaging.listUsers.
4. Fill in the parameter fields that appear. Use {{...}} to reference upstream values.

What it returns

The API Call node writes the response to the workflow context:

{
  status: 200,
  success: true,
  data: { ...response body from the API... },
  latencyMs: 142
}

Reference response fields downstream as {{nodeId.data.path}}. The exact response shape is documented on the upstream Slack API reference.

GET /users.info

Get user profile info

Detail	Value
Operation ID	messaging.getUserInfo
Method	GET
Path	/users.info

Parameters

Name	Location	Type	Required
user	query	string	Yes

Using this endpoint in a workflow

1. Add an API Call node to your workflow.
2. Pick your Slack connection from the Connection dropdown.
3. In the Operation dropdown, select messaging.getUserInfo.
4. Fill in the parameter fields that appear. Use {{...}} to reference upstream values.

Required fields are marked — fill them or the call will fail at runtime.

What it returns

The API Call node writes the response to the workflow context:

{
  status: 200,
  success: true,
  data: { ...response body from the API... },
  latencyMs: 142
}

Reference response fields downstream as {{nodeId.data.path}}. The exact response shape is documented on the upstream Slack API reference.

POST /reactions.add

Add a reaction to a message

Detail	Value
Operation ID	messaging.addReaction
Method	POST
Path	/reactions.add

Parameters

No parameters.

Request Body

Field	Type
channel	string
timestamp	string
name	string

Using this endpoint in a workflow

1. Add an API Call node to your workflow.
2. Pick your Slack connection from the Connection dropdown.
3. In the Operation dropdown, select messaging.addReaction.
4. Fill in the parameter fields that appear. Use {{...}} to reference upstream values.

Required fields are marked — fill them or the call will fail at runtime.

What it returns

The API Call node writes the response to the workflow context:

{
  status: 200,
  success: true,
  data: { ...response body from the API... },
  latencyMs: 142
}

Reference response fields downstream as {{nodeId.data.path}}. The exact response shape is documented on the upstream Slack API reference.