MCP Tools

MCP (Model Context Protocol) servers provide external tools that extend pi's capabilities. Tools from MCP servers are named {serverName}__{toolName} — e.g., github__search_code.

Adding Servers

Use /unipi:mcp-add to browse the catalog of 7,800+ MCP servers and add them interactively. The split-pane overlay lets you:

• Browse: Search the cached server catalog by name, description, or category
• Select: Pick a server to get a pre-filled config template
• Custom: Press c for an empty editor to add unlisted servers manually
• Save: Press Enter or Ctrl+S to validate and save

Managing Servers

Use /unipi:mcp-settings to manage configured servers:

• Toggle: Press Space to enable/disable a server
• Delete: Press d then y to remove a server
• Scope: Press g for global config, p for project config
• Sync: Press s to refresh the catalog from GitHub

Quick Status

Use /unipi:mcp-status for a text summary of all servers and their status.

Config Hierarchy

MCP config supports global defaults with project overrides:

~/.unipi/config/mcp/              ← Global defaults (shared across all projects)
{project}/.unipi/config/mcp/      ← Project overrides (when present)

Merge rules:

1. Server only in global → used normally
2. Server only in project → used normally
3. Server in both → project wins entirely
4. enabled: false in project metadata → disabled even if defined globally

Config Files

Each level has three files:

• mcp-config.json — Server definitions (standard MCP format, portable)
• config.json — Metadata (enabled/disabled, sync prefs)
• auth.json — Sensitive env vars (optional, chmod 600)

Example mcp-config.json

{
  "mcpServers": {
    "github": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "GITHUB_PERSONAL_ACCESS_TOKEN", "ghcr.io/github/github-mcp-server"],
      "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "ghp_xxxx" }
    },
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/home/pi/projects"]
    }
  }
}

Using MCP Tools

Once an MCP server is running, its tools are available as pi tools. They're named with the pattern {serverName}__{toolName}.

For example, if you add the GitHub MCP server, you'll have tools like:

• github__search_code
• github__create_issue
• github__list_pull_requests

You can call these tools directly in conversations.

Troubleshooting

Server won't start

• Check /unipi:mcp-status for error details
• Verify the command exists: which npx or which docker
• Check that required env vars are set in the config

Tools not appearing

• Ensure the server status shows "running"
• Check if the server supports the MCP tools protocol
• Try restarting pi after adding a new server

Config issues

• Validate JSON syntax in your config files
• Check file permissions (mcp-config.json should be readable)
• Use /unipi:mcp-settings to view current configuration

Catalog sync issues

• Run /unipi:mcp-sync to force a refresh
• Check network connectivity to GitHub
• The seed catalog (49 servers) is available offline as fallback