chat_post_message
Send a message to any Slack channel, direct message, or thread. Supports text, Block Kit blocks, attachments, and threaded replies.
Instructions
Send a message to a channel.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| channel | Yes | ID of the channel to post to (e.g. ``C0123``), or a DM ID (``D0123``) or user ID for a DM. | |
| text | No | Message text or fallback text when ``blocks`` are provided. Supports Slack mrkdwn. | |
| attachments | No | Legacy attachment array. Prefer ``blocks`` for new messages. | |
| blocks | No | Block Kit block array defining the message layout. | |
| as_user | No | Post as the authenticated user rather than as the bot (legacy; ignored for workspace apps). | |
| icon_emoji | No | Emoji to use as the bot icon, overrides the app default (e.g. ``:robot_face:``); needs ``username``. | |
| icon_url | No | URL of an image to use as the bot's icon. Requires ``username``. | |
| link_names | No | Find and link channel names and usernames in ``text`` (e.g. ``#general`` → hyperlink). | |
| metadata | No | Structured metadata object attached to the message (``event_type`` + ``event_payload``). | |
| mrkdwn | No | Render Slack mrkdwn formatting in ``text`` (default True). | |
| parse | No | How to handle message text: ``full`` (linkify everything) or ``none`` (pass text as-is). | |
| reply_broadcast | No | Also post the threaded reply to the channel when ``thread_ts`` is set. | |
| thread_ts | No | Timestamp of the parent message to reply to, forming a thread (e.g. ``1700000000.000100``). | |
| unfurl_links | No | Automatically unfurl URL links in the message. | |
| unfurl_media | No | Automatically unfurl media URLs (images, video) in the message. | |
| username | No | Override the bot's display name for this message. |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||