ask_on_slackLABSCO SUMMARY
The timeout sets what you can ask.
Sixty seconds means this works for a question the person can answer from memory while looking at Slack, and not for one that needs them to go and check. Write the question with that in mind, and note that the answer has to land in the thread — a reply in the main channel is not seen.
What it is
An MCP server that turns a human into a tool the model can call. When the assistant hits something it cannot know — an internal endpoint, a decision only you can make — it posts the question into a Slack channel, mentions the person you configured, and blocks until they answer in the thread or the timeout passes.
What you get
ask_on_slack— one tool, taking a singlequestionstring, returning what the human wrote back- The question posted with an
@usernamemention so it actually gets noticed - Thread-based replies, which keeps the conversation attached to the question that started it
- A 60-second window for the answer, after which the call times out
- A live Socket Mode WebSocket connection, so a reply is picked up as soon as it is posted
Requirements
A Slack app in your workspace with Socket Mode enabled and the Events API on, subscribed to message.channels and message.groups. You need two tokens and two IDs, all passed as command-line arguments: --slack-bot-token starting xoxb-, --slack-app-token starting xapp- with the connections:write scope, --slack-channel-id and --slack-user-id. The bot token needs chat:write, channels:read and users:read, and the bot has to be invited to the channel. Run it with npx github:trtd56/AskOnSlackMCP and the four arguments. Package human-in-the-loop-slack-mcp at 0.1.0, MIT.
Setup effort
One command plus a key — npx github:trtd56/AskOnSlackMCP, then supply credentials
USE CASES
01
Getting a value the assistant cannot look up
Ask for the production endpoint or the account name and let a colleague answer instead of the model guessing.
02
Confirming before something irreversible
Have the agent check in with a named person before the step it cannot undo.
03
Resolving an ambiguous instruction
When a request could mean two things, ask which one rather than picking and being wrong for the rest of the run.
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
npx on PATH
Where it runs
The documented client runs the server on your machine.
INSTALLATION
Connect your client
Server setup
TERMINAL
npx github:trtd56/AskOnSlackMCPMCP Clients
Claude Desktop
CLAUDE DESKTOP · JSON
{
"mcpServers": {
"slack-human": {
"command": "npx",
"args": [
"github:trtd56/AskOnSlackMCP",
"--slack-bot-token",
"<YOUR_TOKEN>",
"--slack-app-token",
"<YOUR_TOKEN>",
"--slack-channel-id",
"C1234567890",
"--slack-user-id",
"U1234567890"
]
}
}
}
