Read recent messages from a channel the bot is in. (docs)
GET conversations.history
🟢 low
— no
What the agent can do
Capability
API call
Risk
Needs approval
Send a message to a Slack channel, DM, or thread as the bot. (docs)
POST chat.postMessage
🟡 medium
✅ yes
Connecting it
You provide: Bot User OAuth Token (xoxb-)
Where to get it: api.slack.com/apps → Create New App → OAuth & Permissions → add Bot Token Scopes (chat:write, channels:history) → Install to Workspace → copy the Bot User OAuth Token. Invite the bot to target channels (or add chat:write.public). For inbound: Event Subscriptions → add this app's events URL → subscribe to message.channels / message.im.
Permissions/scopes:chat:write, channels:history
Account setup
Account needed: A Slack workspace with permission to install apps (admin approval may be required).
App registration: api.slack.com/apps → Create New App → OAuth & Permissions → add bot scopes (chat:write, channels:history, +chat:write.public if needed) → Install to Workspace → copy xoxb- token → invite the bot to channels → Event Subscriptions for inbound.
Verification required: Slack App Directory (Marketplace) listing requires Slack's review; not required for internal single-workspace apps.
Testing: Use your own free Slack developer workspace for development before distribution.
Limits
chat.postMessage is specially limited to ~1 message/sec per channel (with short bursts); Web API methods otherwise fall into Tier 1-4 per-minute limits.