post_slack_messageLABSCO SUMMARY
One tool, two ways in — webhook for a single channel, bot token when you need scopes.
Webhook mode is the shorter path: paste the hooks.slack.com URL on the launch command and posting works without installing an app with permissions. Bot mode costs an app install and the chat:write scopes, and in exchange the same tool takes channel IDs, a username and an emoji, so the message arrives looking the way you want it to.
What it is
A Slack posting server built around one tool: it sends a message to a channel, either through an incoming webhook URL or with a bot user token, whichever you configure on the launch command.
What you get
- A message posted to a Slack channel in a single call, through post_slack_message
- Webhook posting from a hooks.slack.com URL, with no scopes to approve
- Bot posting with an xoxb- token and the chat:write and chat:write.public scopes
- A per-message channel override, so one server reaches more than its default channel
- Slack's own mention syntax passed through intact: <!channel>, <!here> and <@USERID>
- A bot username and icon emoji set once on the launch command
Requirements
A Slack app with either an incoming webhook URL or a bot user OAuth token starting with xoxb-. Bot mode wants the channel ID rather than the name, and the chat:write plus chat:write.public scopes. Runs with bun from a local checkout.
Setup effort
Build from source — git clone https://github.com/SilasReinagel/slack-notify-mcp
USE CASES
01
Telling the team a long job finished
Send the result to the default channel as the last step of the task, instead of switching to Slack to type it.
02
Getting an incident in front of whoever is online
Include <!here> in the message text — Slack's mention syntax goes through unchanged, so it pings rather than printing literally.
03
Sending one message somewhere other than the usual channel
Override the channel on the call, so a single configured server can post to any channel it has access to.
04
Making automated posts recognisable at a glance
Set a bot username and icon emoji on the launch command so every message arrives under the same identity.
1 tool
Listed in project docs. Your client may show a different list.
BEFORE YOU INSTALL
What to know first
Tools you get
1 tool named in the project's documentation.
Requires
bun on PATH
Where it runs
The documented client runs the server on your machine.
INSTALLATION
Connect your client
You clone this one yourself.
Server setup
TERMINAL
git clone https://github.com/SilasReinagel/slack-notify-mcp
cd slack-notify-mcp
bun installMCP Clients
Any MCP client
ANY MCP CLIENT · JSON
{
"mcpServers": {
"slack-webhook": {
"command": "bun",
"args": [
"run",
"src/index.ts",
"--webhook-url",
"https://hooks.slack.com/services/YOUR/SLACK/WEBHOOK",
"--channel",
"#general"
],
"cwd": "<YOUR_PATH_TO_SLACK_NOTIFY_MCP>"
}
}
}
