Slack Integration

Send messages and interact with your team's Slack workspace

Prerequisites

•SLACK_BOT_TOKEN environment variable must be set (provided automatically when connected in Settings)
•Bot must be invited to channels you want to post to

Sending Messages

To a Public Channel

bash

curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "general",
    "text": "Hello from the agent!"
  }'

To a Channel by ID

bash

curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "C01234567",
    "text": "Hello!"
  }'

With Formatting (Blocks)

bash

curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "general",
    "blocks": [
      {
        "type": "section",
        "text": {
          "type": "mrkdwn",
          "text": "*Task Complete*\nDeployed version 1.2.3 to production"
        }
      }
    ]
  }'

Reading Messages

Get Channel History

bash

curl "https://slack.com/api/conversations.history?channel=C01234567&limit=20" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

Get Thread Replies

bash

curl "https://slack.com/api/conversations.replies?channel=C01234567&ts=1234567890.123456" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

Finding Channels

List Public Channels

bash

curl "https://slack.com/api/conversations.list?types=public_channel" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

List Private Channels (requires groups:read scope)

bash

curl "https://slack.com/api/conversations.list?types=private_channel" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

Threading

Reply in a Thread

bash

curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "C01234567",
    "thread_ts": "1234567890.123456",
    "text": "This is a reply in the thread"
  }'

Looking Up Users

bash

curl "https://slack.com/api/users.list" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

Environment Variables

Variable	Description
`SLACK_BOT_TOKEN`	Bot User OAuth Token (xoxb-...)
`SLACK_TEAM_ID`	Workspace ID
`SLACK_TEAM_NAME`	Workspace name

Best Practices

•Use threads to avoid channel noise when posting updates
•Keep messages concise and actionable
•Tag users sparingly - only when they need to take action
•Use blocks for structured content like reports or summaries
•Check channel membership before posting to private channels

Required Bot Token Scopes

Minimum scopes for basic functionality:

•chat:write - Send messages
•channels:read - List public channels
•channels:history - Read public channel messages

Optional scopes for extended functionality:

•groups:read - List private channels
•groups:history - Read private channel messages
•users:read - Look up users
•files:write - Upload files

Error Handling

Always check the response for errors:

json

{
  "ok": false,
  "error": "channel_not_found"
}

Common errors:

•channel_not_found - Channel doesn't exist or bot isn't a member
•not_in_channel - Bot needs to be invited to the channel
•invalid_auth - Token is invalid or expired