xbrowser Adds MCP Server in One Day, Built Without Official SDK

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Browser-automation CLI tool xbrowser shipped a stdio-based Model Context Protocol server in version 1.23.1, exposing 7 browser tools to AI agents such as Claude Desktop and Cursor. The team deliberately skipped the official MCP SDK, instead hand-writing a roughly 60-line JSON-RPC 2.0 protocol layer to avoid new dependencies and keep the code fully debuggable. All MCP tool calls route through the same internal functions used by the existing CLI, meaning the tool inherits xbrowser's full 4,000-test suite and any future engine improvements automatically. Two bugs were caught during initial smoke testing: the CLI mistakenly tried to execute protocol JSON as browser commands, and a shutdown race condition triggered early process exit while the browser was still launching. Both issues were fixed before release, and the team notes the experience highlights why thin, hand-written protocol layers are preferable for globally installed CLI tools.

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