How We Built Three MCP Servers to Make OpenClaw Actually Useful in Slack

The Slack MCP server that ships with OpenClaw does about 60% of what you need. It can read messages, send replies, and handle threads. What it can't do is the interesting stuff: pulling context from your actual tools, enforcing permissions, or doing anything that requires understanding your specific workflow. We built three custom MCP servers to close that gap. Two months in, they're handling roughly 400 Slack interactions per day across our team. Here's what they do and how we built them. Quick MCP Primer (Skip If You Know This) MCP (Model Context Protocol) is how OpenClaw talks to external tools. Each MCP server exposes a set of "tools" that the agent can call. You register them in ~/.openclaw/mcp.json , and the agent figures out when to use them based on what someone asks. The Slack MCP server gives you basics: send_message , read_channel , reply_to_thread , upload_file . But these are generic. They don't know about your Linear tickets, your Notion docs, or your deployment pipeline.