Model Context Protocol (MCP) in LastBrowser

The Model Context Protocol (MCP) is an open standard that lets AI assistants securely interact with external data sources, filesystems and developer tools. LastBrowser supports MCP natively in the Sidekick engine core.

Configuration file: mcp_servers.json

MCP servers are defined in %APPDATA%\Lastbrowser\mcp_servers.json. Any tool that communicates via stdio or SSE can be connected:

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres", "postgresql://localhost/mydb"]
    },
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "YOUR_TOKEN"
      }
    }
  }
}

How Sidekick interacts with MCP tools

1. Tool discovery: On startup, the Sidekick engine queries the available capabilities of the MCP server (tools/list).
2. Contextual selection: When you ask Sidekick a question (e.g. “Show me the last 5 commits in the repo”), Sidekick automatically selects the matching GitHub tool.
3. Human confirmation: Sensitive actions (disk writes or SQL updates) require your confirmation in the chat before execution.

Catalog of preconfigured MCP servers

Visit our MCP & Extension Hub to discover curated server definitions with 1-click import.