Slack

Slack

Access the Slack API with managed OAuth authentication. Send messages, manage channels, list users, and automate Slack workflows.

Quick Start

# Post a message to a channel
python <<'EOF'
import urllib.request, os, json
data = json.dumps({'channel': 'C0123456789', 'text': 'Hello from Maton!'}).encode()
req = urllib.request.Request('https://api.maton.ai/slack/api/chat.postMessage', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Base URL

https://api.maton.ai/slack/{method}

Maton proxies requests to slack.com and automatically injects your OAuth token.

Authentication

All requests require the Maton API key in the Authorization header:

Authorization: Bearer $MATON_API_KEY

Environment Variable: Set your API key as MATON_API_KEY:

export MATON_API_KEY="YOUR_API_KEY"

Getting Your API Key

1. Sign in or create an account at maton.ai
2. Go to maton.ai/settings
3. Copy your API key

Connection Management

Manage your Slack OAuth connections at https://api.maton.ai.

List Connections

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections?app=slack&status=ACTIVE')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create Connection

python <<'EOF'
import urllib.request, os, json
data = json.dumps({'app': 'slack'}).encode()
req = urllib.request.Request('https://api.maton.ai/connections', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Get Connection

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections/{connection_id}')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Response:

{
  "connection": {
    "connection_id": "{connection_id}",
    "status": "ACTIVE",
    "creation_time": "2025-12-08T07:20:53.488460Z",
    "last_updated_time": "2026-01-31T20:03:32.593153Z",
    "url": "https://connect.maton.ai/?session_token=...",
    "app": "slack",
    "metadata": {}
  }
}

Open the returned url in a browser to complete OAuth authorization.

Delete Connection

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections/{connection_id}', method='DELETE')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Specifying Connection

If you have multiple Slack connections, specify which one to use with the Maton-Connection header:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({'channel': 'C0123456789', 'text': 'Hello!'}).encode()
req = urllib.request.Request('https://api.maton.ai/slack/api/chat.postMessage', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Maton-Connection', '{connection_id}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

If you have multiple connections, always include this header to ensure requests go to the intended account.

Security & Permissions

• Access is scoped to messages, channels, users, files, and reactions within the connected Slack account.
• All write operations require explicit user approval. Before executing any create, update, or delete call, confirm the target resource and intended effect with the user.

API Reference

Authentication

Auth Test

GET /slack/api/auth.test

Returns current user and team info.

Messages

Post Message

POST /slack/api/chat.postMessage
Content-Type: application/json

{
  "channel": "C0123456789",
  "text": "Hello, world!"
}

With blocks:

POST /slack/api/chat.postMessage
Content-Type: application/json

{
  "channel": "C0123456789",
  "blocks": [
    {"type": "section", "text": {"type": "mrkdwn", "text": "*Bold* and _italic_"}}
  ]
}

Post Thread Reply

POST /slack/api/chat.postMessage
Content-Type: application/json

{
  "channel": "C0123456789",
  "thread_ts": "1234567890.123456",
  "text": "This is a reply in a thread"
}

Update Message

POST /slack/api/chat.update
Content-Type: application/json

{
  "channel": "C0123456789",
  "ts": "1234567890.123456",
  "text": "Updated message"
}

Delete Message

POST /slack/api/chat.delete
Content-Type: application/json

{
  "channel": "C0123456789",
  "ts": "1234567890.123456"
}

Schedule Message

POST /slack/api/chat.scheduleMessage
Content-Type: application/json

{
  "channel": "C0123456789",
  "text": "Scheduled message",
  "post_at": 1734567890
}

List Scheduled Messages

GET /slack/api/chat.scheduledMessages.list

Delete Scheduled Message

POST /slack/api/chat.deleteScheduledMessage
Content-Type: application/json

{
  "channel": "C0123456789",
  "scheduled_message_id": "Q1234567890"
}

Get Permalink

GET /slack/api/chat.getPermalink?channel=C0123456789&message_ts=1234567890.123456

Conversations (Channels)

List Channels

GET /slack/api/conversations.list?types=public_channel,private_channel&limit=100

Types: public_channel, private_channel, im, mpim

Get Channel Info

GET /slack/api/conversations.info?channel=C0123456789

Get Channel History

GET /slack/api/conversations.history?channel=C0123456789&limit=100

With time range:

GET /slack/api/conversations.history?channel=C0123456789&oldest=1234567890&latest=1234567899

Get Thread Replies

GET /slack/api/conversations.replies?channel=C0123456789&ts=1234567890.123456

Get Channel Members

GET /slack/api/conversations.members?channel=C0123456789&limit=100

Create Channel

POST /slack/api/conversations.create
Content-Type: application/json

{
  "name": "new-channel-name",
  "is_private": false
}

Join Channel

POST /slack/api/conversations.join
Content-Type: application/json

{
  "channel": "C0123456789"
}

Leave Channel

POST /slack/api/conversations.leave
Content-Type: application/json

{
  "channel": "C0123456789"
}

Archive Channel

POST /slack/api/conversations.archive
Content-Type: application/json

{
  "channel": "C0123456789"
}

Unarchive Channel

POST /slack/api/conversations.unarchive
Content-Type: application/json

{
  "channel": "C0123456789"
}

Rename Channel

POST /slack/api/conversations.rename
Content-Type: application/json

{
  "channel": "C0123456789",
  "name": "new-name"
}

Set Channel Topic

POST /slack/api/conversations.setTopic
Content-Type: application/json

{
  "channel": "C0123456789",
  "topic": "Channel topic here"
}

Set Channel Purpose

POST /slack/api/conversations.setPurpose
Content-Type: application/json

{
  "channel": "C0123456789",
  "purpose": "Channel purpose here"
}

Invite to Channel

POST /slack/api/conversations.invite
Content-Type: application/json

{
  "channel": "C0123456789",
  "users": "U0123456789,U9876543210"
}

Kick from Channel

POST /slack/api/conversations.kick
Content-Type: application/json

{
  "channel": "C0123456789",
  "user": "U0123456789"
}

Mark Channel Read

POST /slack/api/conversations.mark
Content-Type: application/json

{
  "channel": "C0123456789",
  "ts": "1234567890.123456"
}

Direct Messages

Open DM Conversation

POST /slack/api/conversations.open
Content-Type: application/json

{
  "users": "U0123456789"
}

For group DM:

POST /slack/api/conversations.open
Content-Type: application/json

{
  "users": "U0123456789,U9876543210"
}

List DM Channels

GET /slack/api/conversations.list?types=im

List Group DM Channels

GET /slack/api/conversations.list?types=mpim

My Conversations

GET /slack/api/users.conversations?limit=100

Users

List Users

GET /slack/api/users.list?limit=100

Get User Info

GET /slack/api/users.info?user=U0123456789

Get User Presence

GET /slack/api/users.getPresence?user=U0123456789

Set User Presence

POST /slack/api/users.setPresence
Content-Type: application/json

{
  "presence": "away"
}

Lookup User by Email

GET /slack/api/users.lookupByEmail?email=user@example.com

Reactions

Add Reaction

POST /slack/api/reactions.add
Content-Type: application/json

{
  "channel": "C0123456789",
  "name": "thumbsup",
  "timestamp": "1234567890.123456"
}

Remove Reaction

POST /slack/api/reactions.remove
Content-Type: application/json

{
  "channel": "C0123456789",
  "name": "thumbsup",
  "timestamp": "1234567890.123456"
}

Get Reactions on Message

GET /slack/api/reactions.get?channel=C0123456789&timestamp=1234567890.123456

List My Reactions

GET /slack/api/reactions.list?limit=100

Stars

List Stars

GET /slack/api/stars.list?limit=100

Add Star

POST /slack/api/stars.add
Content-Type: application/json

{
  "channel": "C0123456789",
  "timestamp": "1234567890.123456"
}

Remove Star

POST /slack/api/stars.remove
Content-Type: application/json

{
  "channel": "C0123456789",
  "timestamp": "1234567890.123456"
}

Bots

Get Bot Info

GET /slack/api/bots.info?bot=B0123456789

Files

Upload File

POST /slack/api/files.upload
Content-Type: multipart/form-data

channels=C0123456789
content=file content here
filename=example.txt
title=Example File

Upload File v2 (Get Upload URL)

GET /slack/api/files.getUploadURLExternal?filename=example.txt&length=1024

Complete File Upload

POST /slack/api/files.completeUploadExternal
Content-Type: application/json

{
  "files": [{"id": "F0123456789", "title": "My File"}],
  "channel_id": "C0123456789"
}

Delete File

POST /slack/api/files.delete
Content-Type: application/json

{
  "file": "F0123456789"
}

Get File Info

GET /slack/api/files.info?file=F0123456789

Search

Search Messages

GET /slack/api/search.messages?query=keyword

Code Examples

JavaScript

const response = await fetch('https://api.maton.ai/slack/api/chat.postMessage', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'Authorization': `Bearer ${process.env.MATON_API_KEY}`
  },
  body: JSON.stringify({ channel: 'C0123456', text: 'Hello!' })
});
const result = await response.json();
console.log(result);

Python

import os
import requests

response = requests.post(
    'https://api.maton.ai/slack/api/chat.postMessage',
    headers={'Authorization': f'Bearer {os.environ["MATON_API_KEY"]}'},
    json={'channel': 'C0123456', 'text': 'Hello!'}
)
print(response.json())

Notes

• Channel IDs: C (public), G (private/group), D (DM)
• User IDs start with U, Bot IDs start with B, Team IDs start with T
• Message timestamps (ts) are unique identifiers
• Use mrkdwn type for Slack-flavored markdown formatting
• Thread replies use thread_ts to reference the parent message
• Cursor-based pagination: use cursor from response_metadata.next_cursor

Shell Notes

• IMPORTANT: When using curl commands, use curl -g when URLs contain brackets (fields[], sort[], records[]) to disable glob parsing
• IMPORTANT: When piping curl output to jq or other commands, environment variables like $MATON_API_KEY may not expand correctly in some shell environments. You may get "Invalid API key" errors when piping.

Error Handling

Missing Scope Errors: If you encounter missing_scope errors, contact Maton Support to request additional scopes for your connection.

Troubleshooting: API Key Issues

1. Check that the MATON_API_KEY environment variable is set:

echo $MATON_API_KEY

2. Verify the API key is valid by listing connections:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Troubleshooting: Invalid App Name

1. Ensure your URL path starts with slack. For example:

• Correct: https://api.maton.ai/slack/api/chat.postMessage
• Incorrect: https://api.maton.ai/api/chat.postMessage

Resources

• Slack API Methods
• Web API Reference
• Block Kit Reference
• Message Formatting
• Rate Limits
• Maton Community
• Maton Support