A Python mock Slack MCP server for testing and development. This server provides offline Slack-like tools backed by JSON state and Pydantic validation.

Tools

The server exposes tools for:

channels and direct messages
messages and thread replies
search
reactions and pins
users, profiles, presence, and status
file upload/listing
state import/export for fixture setup and grading

Usage

Development

uv run --package slack-mock python -m slack_mock

Tests

uv run --package slack-mock pytest packages/slack/tests

MCP Configuration

packages/slack/mcp.json runs the server through uv run --package slack-mock python -m slack_mock.

Notes

This is a fully offline mock server. No actual Slack API calls are made.