MCP Servers Don't Work with NVM #64

combdn · 2024-11-26T18:23:23Z

Problem

When using NVM (Node Version Manager), the standard installation and usage instructions for MCP servers don't work. The app tries to use an incorrect Node and fails.

Workaround

Avoid npx, install packages globally.
Use absolute paths to both the Node executable and server script.

Example:

{  
  "mcpServers": {
    "puppeteer": {
      "command": "/Users/username/.nvm/versions/node/v22.11.0/bin/node",
      "args": [
        "/Users/username/.nvm/versions/node/v22.11.0/lib/node_modules/@modelcontextprotocol/server-puppeteer/dist/index.js"
      ]
    }
  }
}

OS: macOS 15.1.1 (24B91)

The text was updated successfully, but these errors were encountered:

mckaywrigley · 2024-11-26T23:36:58Z

I also ran into issues with the recommended npx setup, and I was able to successfully reproduce this workaround - fixes it completely.

MCPs now install and attach correctly within Claude Desktop.

lborgav · 2024-11-27T02:46:11Z

This workaround works fine

adam91holt · 2024-11-27T07:52:43Z

I can confirm this is working for me too.

You may have a different node.js version installed so just do the following for puppeteer as an example

npm i -g @modelcontextprotocol/server-puppeteer
cd /Users/YOUR_USERNAME/.nvm/versions/node
ls
>>> v14.17.6        v16.19.0        v18.14.0        v18.20.4

Then I ended up with this and it works sweet!

{
  "mcpServers": {
    "puppeteer": {
      "command": "/Users/YOUR_USERNAME/.nvm/versions/node/v18.20.4/bin/node",
      "args": [
        "/Users/YOUR_USERNAME/.nvm/versions/node/v18.20.4/lib/node_modules/@modelcontextprotocol/server-puppeteer/dist/index.js"
      ]
    }
  }
}

jspahrsummers · 2024-11-27T14:06:18Z

The challenge with NVM is that it seems to mostly work by installing a very complicated shell function into your shell profile. It'd be great if we could figure out your preferred Node version via NVM, but I haven't found a good way to do that—open to ideas!

jspahrsummers · 2024-11-27T14:07:52Z

Cross-linking: see #40 for Windows workaround steps as well

lolochka · 2024-12-04T10:19:05Z

Unfortunately, the issue is still reproducible on Mac with nvm installed.

OS: macOS 15.1.1
Claude: 0.7.5
Locally I have checked that all packages are available with inputted paths.

The SQlite server is working correctly, but tools for server-filesystem doesn't appear

My settings

{
  "mcpServers": {
    "sqlite": {
      "command": "uvx",
      "args": ["mcp-server-sqlite", "--db-path", "/Users/user/test.db"]
    },
    "filesystem": {
      "command": "/Users/user/.nvm/versions/node/v22.11.0/bin/node",
      "args": [
        "-y",
        "/Users/user/.nvm/versions/node/v22.11.0/lib/node_modules/@modelcontextprotocol/server-filesystem/dist/index.js",
        "/Users/user/claude"
      ]
    }
  }
}

mlaugharn · 2024-12-07T01:17:59Z

suggestion: the same way that there is the mcpServers field, can there also be an eg mcpShell field? Or maybe a shell or source key per individual server, eg "shell": "source /Users/user/mcp.sh" ? Might introduce 'too much' flexibility but it could make mcp more usable/transparent to tinker with.

daaain · 2024-12-08T22:55:19Z

I was struggling to get MCP working yesterday, the error messages in the logs were unhelpful, and the most confusing of all is that it just started working today. This might not be the repo for this request, but it would be really useful if it was explicily documented which shell Claude Desktop is using to start the MCP services.

To your question @jspahrsummers, wouldn't nvm alias default work?

jspahrsummers · 2024-12-09T13:27:49Z

Unfortunately no, the environment for GUI apps is completely different from what you see on the command line.

daaain · 2024-12-09T14:19:39Z

Unfortunately no, the environment for GUI apps is completely different from what you see on the command line.

Ah right, I had a look and to answer my own question, assuming that Claude Desktop's Electron implementation uses the MCP TS SDK, it's node:child_process spawn with shell: false.

combdn · 2024-12-09T15:17:29Z

In the meantime, I have migrated from NVM to mise, and now, if I start the Claude app from my shell (open -a Claude), it can correctly use node and npm (it didn’t work with NVM). That might be a workaround for some people with the same problem.

PS Apple seems to have removed an option to set up the environment for the GUI apps through the launch agents. But I'm not sure. I didn’t dive too deep into it.

daaain · 2024-12-09T17:19:31Z

I was going to say check if path.join(process.env.HOME, '.nvm/nvm-exec') exists and if so, use it, but then also realised that path won't be the same for Windows and the config JSON doesn't specify if the MCP server is Node or Python and using npx -y is just a convention, so can't assume anything.

Feels like the current implementation is in a bit of an uncanny valley between being very open for people to run whatever they want while also very limited by the GUI spawned non-shell process 🤔 I'm wondering if offering the option to either use bundled runtimes for simplicity or running in a full shell for flexibility would be useful? That's what Mac Git GUIs I've used have been doing to solve similar issues. Or WASM 😅

Or actually, maybe having a separate daemon process to make this easier, especially if there are plans to integrate Claude deeper for computer use?

Edit: actually, ~/.nvm/alias/default is a simple text file with the NVM default node version, so if it exists then it can be used to construct a platform dependent path to the Node binary.

BTW MCPs stopped working with my Claude Desktop again, the errors in logs suggest it might be a command argument concat issue?

mcp-server-webresearch.log:

ERROR: You must supply a command.

Execute binaries from npm packages.

  npx [options] <command>[@version] [command-arg]...
...

mcp-server-filesystem.log

command not found: /Users/dain/Desktop

With the config:

{
  "globalShortcut": "",
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "/Users/dain/Desktop"
      ]
    },
    "webresearch": {
      "command": "npx",
      "args": ["-y", "@mzxrai/mcp-webresearch"]
    }
  }
}

lynnbright · 2024-12-10T04:33:29Z

This workaround works for me. Thanks a lot! 🙏
Here's how I successfully installed the MCP servers.

Environment

macOS 14.3
Claude 0.7.5

Installation Steps

Check your Node.js version:

node -v
# Example output: v18.17.0

Clone and set up the repository:

git clone <repository-url>
cd <repository-name>
npm install
npm run build
npm link

Configure `claude_desktop_config.json`

Locate Required Paths

Find your Node.js executable path:

cd ~/.nvm/versions/node
ls  # List available Node versions
cd v18.17.0/bin  # Replace with your version
pwd  # Copy this path + /node for the command field
# Example output: /Users/lynnbright/.nvm/versions/node/v18.17.0/bin/node

Find the built file path:

cd ~/.nvm/versions/node/v18.17.0/lib/node_modules/linear-mcp-server/build
pwd  # Copy this path + /index.js for the args field
# Example output: /Users/lynnbright/.nvm/versions/node/v18.17.0/lib/node_modules/linear-mcp-server/build/index.js

Example Configuration

{
  "mcpServers": {
    "sqlite": {
      "command": "uvx",
      "args": [
        "mcp-server-sqlite",
        "--db-path",
        "/Users/lynnbright/test.db"
      ]
    },
    "linear": {
      "command": "/Users/lynnbright/.nvm/versions/node/v18.17.0/bin/node",
      "args": [
        "/Users/lynnbright/.nvm/versions/node/v18.17.0/lib/node_modules/linear-mcp-server/build/index.js"
      ],
      "env": {
        "LINEAR_API_KEY": "lin_api_xxxx"
      }
    },
    "notion": {
      "command": "/Users/lynnbright/.nvm/versions/node/v18.17.0/bin/node",
      "args": [
        "/Users/lynnbright/.nvm/versions/node/v18.17.0/lib/node_modules/notion/build/index.js"
      ],
      "env": {
        "NOTION_API_TOKEN": "ntn_xxxxx"
      }
    }
  }
}

Final Step

Restart Claude Desktop.

keturiosakys · 2024-12-11T10:54:37Z

FNM (https://github.com/Schniz/fnm) doesn't work either but the workaround worked!

mearleycf · 2024-12-20T11:26:17Z

In the meantime, I have migrated from NVM to mise, and now, if I start the Claude app from my shell (open -a Claude), it can correctly use node and npm (it didn’t work with NVM). That might be a workaround for some people with the same problem.

PS Apple seems to have removed an option to set up the environment for the GUI apps through the launch agents. But I'm not sure. I didn’t dive too deep into it.

This is the way. Mise is an infinitely better tool than NVM.

gannonh · 2024-12-20T18:21:29Z

Interesting. Btw, the NVM issue goes away if you're only managing 1 version of node. I discovered this inadvertently setting up a new machine. Will check out Mise. First I've heard of it.

mckaywrigley mentioned this issue Nov 26, 2024

MCP servers fail to connect with npx on Windows #40

Closed

This was referenced Nov 27, 2024

Connection failures with npm-based MCP servers while uvx-based servers work correctly (Solved, see the comment in this post) #76

Closed

How to configure windows filesystem? #75

Closed

jspahrsummers added the bug Something isn't working label Nov 27, 2024

jspahrsummers pinned this issue Nov 27, 2024

mmirza1 mentioned this issue Nov 29, 2024

Can't see the Model Context protocol icon on MAC desktop app after adding claude_desktop_config.json file #121

Closed

jspahrsummers unpinned this issue Dec 3, 2024

jspahrsummers pinned this issue Dec 3, 2024

2013xile mentioned this issue Dec 7, 2024

"Could not attach to MCP server" error on MacOS Claude Desktop modelcontextprotocol/typescript-sdk#86

Closed

jspahrsummers mentioned this issue Dec 13, 2024

latest version of Claude desktop still fails to connect with npx on Windows #333

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MCP Servers Don't Work with NVM #64

MCP Servers Don't Work with NVM #64

combdn commented Nov 26, 2024

mckaywrigley commented Nov 26, 2024 •

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lborgav commented Nov 27, 2024 •

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adam91holt commented Nov 27, 2024

jspahrsummers commented Nov 27, 2024

jspahrsummers commented Nov 27, 2024 •

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lolochka commented Dec 4, 2024 •

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mlaugharn commented Dec 7, 2024

daaain commented Dec 8, 2024

jspahrsummers commented Dec 9, 2024

daaain commented Dec 9, 2024

combdn commented Dec 9, 2024

daaain commented Dec 9, 2024 •

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lynnbright commented Dec 10, 2024 •

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keturiosakys commented Dec 11, 2024

mearleycf commented Dec 20, 2024

gannonh commented Dec 20, 2024

MCP Servers Don't Work with NVM #64

MCP Servers Don't Work with NVM #64

Comments

combdn commented Nov 26, 2024

Problem

Workaround

mckaywrigley commented Nov 26, 2024 • edited Loading

lborgav commented Nov 27, 2024 • edited Loading

adam91holt commented Nov 27, 2024

jspahrsummers commented Nov 27, 2024

jspahrsummers commented Nov 27, 2024 • edited Loading

lolochka commented Dec 4, 2024 • edited Loading

mlaugharn commented Dec 7, 2024

daaain commented Dec 8, 2024

jspahrsummers commented Dec 9, 2024

daaain commented Dec 9, 2024

combdn commented Dec 9, 2024

daaain commented Dec 9, 2024 • edited Loading

lynnbright commented Dec 10, 2024 • edited Loading

Environment

Installation Steps

Configure claude_desktop_config.json

Locate Required Paths

Example Configuration

Final Step

keturiosakys commented Dec 11, 2024

mearleycf commented Dec 20, 2024

gannonh commented Dec 20, 2024

mckaywrigley commented Nov 26, 2024 •

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lborgav commented Nov 27, 2024 •

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jspahrsummers commented Nov 27, 2024 •

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lolochka commented Dec 4, 2024 •

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daaain commented Dec 9, 2024 •

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lynnbright commented Dec 10, 2024 •

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Configure `claude_desktop_config.json`