Slack · Messaging

Slack Web API / Post a message

Sends a message to a channel, private group, or IM (docs.slack.dev/reference/methods/chat.postMessage). Requires the chat:write bot scope installed on the workspace.

Private Gateway connection

Data below comes from the configured private Gateway. Provider activation remains governed by its evidence and policy gates.

unverifiedRequest shape unavailableUnverified

Published API evidence

Public metadata only. Response bodies, credentials, and internal review notes are never displayed.

No verification date is claimed. No response capture is claimed.

Request parameters

blocks body · optional
A JSON-based array of structured blocks, presented as a URL-encoded string.
channel body · required
An encoded ID or channel name that represents a channel, private group, or IM channel to send the message to.
reply_broadcast body · optional
Indicates whether the reply should be made visible to everyone in the channel or conversation.
text body · required
The message text.
thread_ts body · optional
Provide another message's ts value to make this message a reply.

Provider docs How to run it