MCP break at 1.6.45, but works in 1.6.26

[Eric-Guo]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Like Dash Dash for macOS - API Documentation Browser, Snippet Manager - Kapeli MCP failed to work,
How to start in local. by Eric-Guo · Pull Request #6 · Kapeli/dash-mcp-server · GitHub

  "mcpServers": {
    "Dash": {
      "command": "/opt/homebrew/bin/uv",
      "args": [
        "--directory",
        "/Users/guochunzhong/git/oss/dash-mcp-server",
        "run",
        "src/dash_mcp_server/server.py"
      ]
    },

Steps to Reproduce

Do the MCP config

Expected Behavior

it should works by calling tools via agent.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.6.45
VSCode Version: 1.99.3
Commit: 3ccce8f55d8cca49f6d28b491a844c699b8719a0
Date: 2025-09-22T18:22:38.013Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.6.0

[Eric-Guo]

Here is a ruby script testing your local MCP.

require ‘ruby_llm’

require ‘ruby_llm/mcp’

RubyLLM.configure do |config|

config.deepseek_api_key = ENV.fetch(“DEEPSEEK_API_KEY”, nil)

config.default_model = “deepseek-chat”

config.log_file = File.join(_dir_, “ruby_llm.log”)

config.log_level = :debug # debug level can also be set to debug by setting RUBYLLM_DEBUG envar to true

end

chat = RubyLLM.chat

# Connect to Dash MCP server

client = RubyLLM::MCP.client(

name: “dash-api”,

transport_type: :stdio,

config: {

command: "/opt/homebrew/bin/uv",

args: \[

  "--directory",

  "/Users/guochunzhong/git/oss/dash-mcp-server",

  "run",

  "src/dash_mcp_server/server.py"

\]

}

)

chat.with_tools(*client.tools)

response = chat.ask(“How to install Ruby based on Ruby on Rails 8 documentation?”)

puts response.content

[condor (Condor (Tee))]

hi @Eric-Guo and thank you for the report. Does the issue persist now also in Cursor 1.7? Please update to latest version.