MCP servers fail to connect with `npx` on Windows #40

naif0s · 2024-11-25T21:00:09Z

I am on Windows with the latest desktop version, I have enabled developer mode and I am in Europe

sean-lynch · 2024-11-25T21:19:40Z

Can you share your %APPDATA%\Claude\claude_desktop_config.json? (In case this doesn't make sense, I'm referring to step 2 in the Windows quickstart guide here: https://modelcontextprotocol.io/quickstart#installation)

naif0s · 2024-11-25T21:23:52Z

jwross24 · 2024-11-25T21:30:06Z

The docs are a bit confusing, and I had a similar issue. You should add the individual MCP servers under the mcpServers key in the JSON like so.

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        ...
      ]
    },
    "memory": {
      "command": "npx",
      "args": [...]
    }
  }
}

They should then show up correctly in the Developer config.

naif0s · 2024-11-25T21:35:46Z

Thank you, it works! Now, how do I integrate Github?

jwross24 · 2024-11-25T21:37:55Z

You should use the github config that you had before, instead of the filesystem and memory configs that I have. You can add it as another key after filesystem and memory, though those configs won't work exactly as I have written since I omitted the args key for brevity.

You can try:

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y",  "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "<YOUR_TOKEN>"
      }
    }
  }
}

naif0s · 2024-11-25T21:48:14Z

OK Thanks, it's super cool for your help. But well... it's not working. I entered the key correctly but when I ask Claude, for example to create an issue, it won't do it

jspahrsummers · 2024-11-25T22:35:57Z

Are you able to get the GitHub server working with the MCP Inspector? That will help narrow down whether this is a desktop app issue, or a problem with the server setup.

geelen · 2024-11-26T00:46:06Z

I've got almost the exact same situation. I have two servers configured:

{
  "mcpServers": {
    "sqlite": {
      "command": "uvx",
      "args": ["mcp-server-sqlite", "--db-path", "/Users/glen/src/experiments/claude-local-sqlite"]
    },
    "brave_search": {
      "command": "npx",
      "args": ["@modelcontextprotocol/server-brave-search"],
      "env": {
        "BRAVE_API_KEY": "<redacted>"
      }
    }
  }
}

My debug log looks fine:

Settings looks fine:

But no 🔌 icon in the chat window:

And a flat refusal to do anything with the connections:

geelen · 2024-11-26T00:53:41Z

Update: just tried on my windows machine, and got the exact same result. Is it possible this is geoblocked in Australia?

ProRedCat · 2024-11-26T01:02:45Z

Same issue here, there is no 🔌, I do have the filesystem server running but I get a message in Claude Desktop of it failing to attach to the MCP server.

To add more context based on what geelen said, I am from New Zealand and running on Windows so could be georestrictions, or it could be some device setup.

Having issues running MCPInspector as well so debugging is a bit difficult

ProRedCat · 2024-11-26T02:25:01Z

Update on my end, I switched over to a MacBook as there seemed to be some issues with running this on Windows see: modelcontextprotocol/inspector#76

For the filesystem server it is now working as well as the Github server. The region locked theory is wrong, it's just device configuration/OS support.

For the SQLite and Brave Search the issues #37 #42 may be helpful for the others in this thread as there seems to be some issues with pathing sometimes - though I am still facing issues on Windows.

geelen · 2024-11-26T02:57:42Z

You're quite right. I had a typo in the path to my DB! That was crashing things, even stopping me from adding other tools.

Sunwood-ai-labs · 2024-11-26T10:26:53Z

I'm also experiencing issues with the filesystem server on Windows. Here's my configuration:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "C:\\Users\\Username\\Desktop"
      ]
    }
  }
}

timurkhakhalev · 2024-11-26T11:22:58Z

Same behavior on Windows 11 and Mac OS. Claude desktop 0.71.1 version on both devices.

Da1sypetals · 2024-11-26T11:58:42Z

I'm also experiencing issues with the filesystem server on Windows. Here's my configuration:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "C:\\Users\\Username\\Desktop"
      ]
    }
  }
}

The same problem with me. My configuration :

{
    "mcpServers": {
        "filesystem": {
            "command": "npx",
            "args": [
                "-y",
                "@modelcontextprotocol/server-filesystem",
                "A:\\Desktop\\"
            ]
        }
    }
}

mckaywrigley · 2024-11-26T12:00:30Z

Experiencing similar issues on Mac OS using Claude Desktop 0.71.1.

mcgraf · 2024-11-26T12:02:42Z

I am having the same issue on Windows 10 with latest Claude Desktop

RELMYMathieu · 2024-11-26T13:59:32Z

Same issue, log file attached:

mike-luabase · 2024-11-26T14:01:07Z

@mckaywrigley what does your config file look like?

code ~/Library/Application\ Support/Claude/claude_desktop_config.json

thenameless7741 · 2024-11-26T14:12:30Z

Here's what works for me (mac):

TL;DR Try using an absolute path and specify the latest Python version in claude_desktop_config.json when configuring uvx.

Detailed version:

I followed the sqlite instructions but ran into a "Could not connect to MCP server sqlite" error.
After enabling developer mode, i checked to the log file through Developer (menu bar) → Open MCP Log File (mcp.log) and found this error "Could not start MCP server sqlite: Error: spawn uvx ENOENT".

The fix was to use an absolute path in claude_desktop_config.json, e.g.

> which uvx
/usr/local/Homebrew/bin/uvx

After restarting Claude, the "Attach from MCP" button still wasn't appearing next to "Upload files" button.
Checking mcp-server-sqlite.log (in the same directory as mcp.log), I saw this error:

No solution found when resolving tool dependencies:
Because the current Python version (3.9.1) does not satisfy Python>=3.10
(omitted)

Since i have a newer Python installed (via miniconda), I resolved this by passing an extra --python arg to uvx, using the absolute path to python binary.

My full JSON config file:

{
  "mcpServers": {
    "sqlite": {
      "command": "/usr/local/Homebrew/bin/uvx",
      "args": [
        "--python",
        "/usr/local/Homebrew/Caskroom/miniconda/base/bin/python3",
        "mcp-server-sqlite",
        "--db-path",
        "/Users/<user>/test.db"
      ]
    }
  }
}

jspahrsummers · 2024-11-26T14:30:50Z

@thenameless7741 Just to check, are you on an Intel Mac? /usr/local/Homebrew isn't searched as part of the path right now, but that's something we could fix.

jspahrsummers · 2024-11-26T14:34:46Z

Sorry folks, and thanks for your patience! For npx calls in particular, we believe there's an issue with how Claude Desktop is launching subprocesses on Windows, which modelcontextprotocol/typescript-sdk#68 (once integrated) should hopefully fix. 🤞

As a workaround, you should be able to npm install -g the MCP servers you care about, and use node to invoke them directly (instead of npx).

thenameless7741 · 2024-11-26T14:58:12Z

@jspahrsummers I'm still using the old Homebrew setup on my M1 and haven't migrated over to the /opt directory yet. I suspect there are a few others out there in the same boat as me.

oscarcalvo · 2024-11-26T15:42:19Z

@jspahrsummers FYI, I'm using Windows. The memory server is installed globally, but it’s still not working. The closest I’ve gotten is with this config, which starts the server, but after 1 minute, Claude shows the same error: 'Couldn't attach...'

"mcpServers": {
"memory": {
"command": "mcp-server-memory",
"args": []
}
}

rkaradas · 2024-11-26T15:59:01Z

@oscarcalvo As @jspahrsummers mentioned, you have to use node directly, like this

{
	"mcpServers" : {
		"filesystem": {
			"command": "node",
			"args": [
			"C:\\Program Files\\nodejs\\node_modules\\@modelcontextprotocol\\server-filesystem\\dist\\index.js", 
			"C:\\"
			]
		}
	}
}

oscarcalvo · 2024-11-26T16:06:41Z

@rkaradas You are right, thanks

timur-khakhalev · 2024-11-26T16:45:57Z

Any ways to access mcp-server inside WSL?

I've tried this but no luck:

"command": "wsl",
            "args":
            [
                "bash",
                "-ic",
                "node /home/timur/dev/personal/mcp/mcp-server-jina/build/index.js"
            ],

"command": "node",
            "args":
            [
                "\\wsl.localhost\\Ubuntu-22\\home\\timur\\dev\\personal\\mcp\\mcp-server-jina\\build\\index.js"
            ],

naif0s · 2024-11-26T17:41:49Z

@oscarcalvo As @jspahrsummers mentioned, you have to use node directly, like this

{
	"mcpServers" : {
		"filesystem": {
			"command": "node",
			"args": [
			"C:\\Program Files\\nodejs\\node_modules\\@modelcontextprotocol\\server-filesystem\\dist\\index.js", 
			"C:\\"
			]
		}
	}
}

THANKS YOU !!!!!!!

FerJSsilva · 2024-12-01T17:57:49Z

@ymdarum Your solution works as well when using nvm for windows. Good Catch Man! You nailed it!

markelaugust74 · 2024-12-01T19:52:19Z

@ymdarum it worked!

DrAnchello · 2024-12-01T20:38:11Z

@ymdarum thanks man, this worked for me as well

fabiendostie · 2024-12-01T22:06:13Z

thank you soooooooomuch for this! it worked for me too

…

On Sun, Dec 1, 2024 at 3:38 PM Angelo Alexander ***@***.***> wrote: @ymdarum <https://github.com/ymdarum> thanks man, this worked for me as well — Reply to this email directly, view it on GitHub <#40 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AM22A2N3JGAILBLC27PQL7T2DNXUVAVCNFSM6AAAAABSO4TCKGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKMJQGI2DCOJUGA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

-- *. | Fabien Dostie* .///Direction Technique / Network Admin / Post-Production Specialist .//Coloriste Resolve / Compositing / Online Editing / AR - VR ./DIT / DMT / Technicien Scene Video (AQTIS 514 - IATSE 56) C: 438.357.3462 W: fabiendostie.com lefab.biz

hemangjoshi37a · 2024-12-02T01:46:06Z

Actually there is similar problem with python based MCP servers . When I try to run it with uvx it fails but when I run it with python command it works fine. I think the MCP servers should be ran in more ancient way using python or npm rather than uvx or npx.

hemangjoshi37a · 2024-12-02T01:48:59Z

Also why in the world is there no linux app of Claude . While more than 90% of development is done on Linux . This is really sad and mine boggling.

hemangjoshi37a · 2024-12-02T04:34:59Z

🎉this works for me :

{
  "mcpServers": {
    "git": {
      "command": "python3.11",
      "args": [
        "-m",
        "mcp_server_git",
        "--repository",
        "C:\\Users\\heman\\Desktop\\test_mcp_git"
      ]
    },
    "memory": {
      "command": "node",
      "args": [
        "C:\\Users\\heman\\AppData\\Roaming\\npm\\node_modules\\@modelcontextprotocol\\server-memory\\dist\\index.js"
      ]
    },
    "filesystem": {
      "command": "node",
      "args": [
        "C:\\Users\\heman\\AppData\\Roaming\\npm\\node_modules\\@modelcontextprotocol\\server-filesystem\\dist\\index.js",
        "C:\\Users\\heman\\Desktop",
        "C:\\Users\\heman\\Desktop\\test_mcp_git"
      ]
    },
    "github": {
      "command": "node",
      "args": [
        "C:\\Users\\heman\\AppData\\Roaming\\npm\\node_modules\\@modelcontextprotocol\\server-github\\dist\\index.js"
      ],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "my-token"
      }
    }
  }
}

przbadu · 2024-12-02T13:23:24Z

Faced the same issue in Mac because my node is setup using node version manager asdf in my case. All I did was Find the npx installation path with which npx. Copy the path to my configuration below e.g: /Users/<me>/.asdf/shims/npx. And it worked for me.

{
  "mcpServers": {
    "github": {
      "command": "/Users/<me>/.asdf/shims/npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-github"
      ],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": ""
      }
    }
  }
}

tagoraiinc · 2024-12-02T14:50:57Z

i am on a windows pc and my servers for filesystem, brave, etc work fine
but the one for gdrive isn't able to authorize
this is my config file:

"gdrive": {
  "command": "node",
  "args": [
    "C:\\Users\\user\\node_modules\\@modelcontextprotocol\\server-gdrive\\dist\\index.js"      ]
}

}

would appreciate any guidance on how to get the gdrive mcp to work, please. thx!

dave2nian · 2024-12-02T15:08:24Z

{ "mcpServers": { "filesystem": { "command": "cmd", "args": [ "/c", "set NODE_DEBUG=* && npx -y @modelcontextprotocol/server-filesystem", "c:\\users\\<youraccountname>\\claude-server" ] } } }

my OS is windwos 11 23h2. I found that even killed all claude tasks, you also need to kill the node.exe process(es, sometime, here were 2 node.exe tasks. )

the guide file "https://modelcontextprotocol.io/quickstart#file-system-access" or sample file "https://github.com/dave2nian/servers/tree/main/src/filesystem" in args part "-y" that mean is auto answer to keep communication with MCP filesystem server. but node.js is a event driven service, it don't need to keep the link. so I tried to change args from -y to /c.

know it is working.

dave2nian · 2024-12-02T15:33:27Z

enjoy it~

jspahrsummers · 2024-12-02T15:49:24Z

Hey folks, there's a new version of Claude Desktop that should resolve issues launching npx on Windows. Please update to v0.7.5 and give it another shot! (If you have any issues auto-updating, you can always download the latest from https://claude.ai/download.)

Thanks for your patience!

anaisbetts · 2024-12-02T16:06:21Z

Our updater is a bit quieter than we'd like, the short version to force the update is, "Help => Check for updates", wait some time, then "File => Exit" and restart the app

TimHuey · 2024-12-02T16:27:43Z

Fixing MCP Server Connection Issues in Claude Desktop

Installation Steps

1. Install Required Packages

npm install -g @modelcontextprotocol/server-filesystem
npm install -g @modelcontextprotocol/server-memory
npm install -g @modelcontextprotocol/server-brave-search
npm install -g @modelcontextprotocol/server-github

2. Update Configuration

Replace content in claude_desktop_config.json:

{
  "mcpServers": {
    "filesystem": {
      "command": "node",
      "args": [
        "C:/Users/YOUR_USERNAME/AppData/Roaming/npm/node_modules/@modelcontextprotocol/server-filesystem/dist/index.js",
        "c:/"
      ]
    },
    "memory": {
      "command": "node",
      "args": [
        "C:/Users/YOUR_USERNAME/AppData/Roaming/npm/node_modules/@modelcontextprotocol/server-memory/dist/index.js"
      ]
    },
    "git": {
      "command": "uvx",
      "args": [
        "mcp-server-git",
        "--repository",
        "C:/Users/YOUR_USERNAME/Projects/NodeJs/super_ai_agents"
      ]
    },
    "brave-search": {
      "command": "node",
      "args": [
        "C:/Users/YOUR_USERNAME/AppData/Roaming/npm/node_modules/@modelcontextprotocol/server-brave-search/dist/index.js"
      ],
      "env": {
        "BRAVE_API_KEY": "YOUR_BRAVE_API_KEY"
      }
    },
    "github": {
      "command": "node",
      "args": [
        "C:/Users/YOUR_USERNAME/AppData/Roaming/npm/node_modules/@modelcontextprotocol/server-github/dist/index.js"
      ],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "YOUR_GITHUB_TOKEN"
      }
    }
  }
}

Note: Replace YOUR_USERNAME, YOUR_BRAVE_API_KEY, and YOUR_GITHUB_TOKEN with your actual values.

This worked for me almost. I just had to replace my local /node_modules/@modelcontextprotocol location. It wasn't the same place as this because I have NVM installed and it was off the NVM directory.

BUT NOW IT WORKS!!!!!!!~ THANK YOU EVERYONE

TimHuey · 2024-12-02T16:29:00Z

OMG, just as I got it fixed and now there is a new version of Claude desktop. Lets go back to the original *config.json and see if it works without the explicit location notation.

TTiagha · 2024-12-02T20:26:05Z

yeah, at least for me, the new update has fixed my connection issue

p1Ktj1XWg1Bm · 2024-12-14T16:21:32Z

I'm also experiencing issues with the filesystem server on Windows. Here's my configuration:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "C:\\Users\\Username\\Desktop"
      ]
    }
  }
}

The same problem with me. My configuration :

{
    "mcpServers": {
        "filesystem": {
            "command": "npx",
            "args": [
                "-y",
                "@modelcontextprotocol/server-filesystem",
                "A:\\Desktop\\"
            ]
        }
    }
}

Same problem on my Win 11. Sad!

TimHuey · 2024-12-18T02:32:28Z

I'm also experiencing issues with the filesystem server on Windows. Here's my configuration:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "C:\\Users\\Username\\Desktop"
      ]
    }
  }
}

The same problem with me. My configuration :

{
    "mcpServers": {
        "filesystem": {
            "command": "npx",
            "args": [
                "-y",
                "@modelcontextprotocol/server-filesystem",
                "A:\\Desktop\\"
            ]
        }
    }
}

Same problem on my Win 11. Sad!

Did you get ANY of the other MCP servers to connect to ClaudeDesktop? Meaning, do you see the tool icon element in the lower right corner of the prompt box area. Are you able to execute any MCP specific actions?

This was referenced Nov 26, 2024

[Claude App] "Could not attach to MCP server github" #42

Closed

[Windows] MCP Server (Brave Search) fails to connect - environment variable issues #52

Closed

hemangjoshi37a mentioned this issue Dec 2, 2024

all npx based servers are failing to start. #152

Closed

This was referenced Dec 2, 2024

brave search connection fail at claude desktop #161

Open

Github connection is not working #155

Closed

Could Not Attach to MCP Server Postgres #102

Open

jspahrsummers closed this as completed Dec 2, 2024

jspahrsummers unpinned this issue Dec 2, 2024

This was referenced Dec 3, 2024

Error connecting to Docker Postgres #71

Closed

MCP Servers Don't Work with NVM #64

Open

GDrive MCP server won't find credentials when used via npx #203

Open

2013xile mentioned this issue Dec 6, 2024

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

Closed

jalenzz mentioned this issue Dec 13, 2024

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

Open

WANGyujian123 mentioned this issue Dec 24, 2024

Stability issue #405

Open

MCP servers fail to connect with npx on Windows #40

MCP servers fail to connect with npx on Windows #40

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naif0s commented Nov 25, 2024

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TimHuey commented Dec 2, 2024

Fixing MCP Server Connection Issues in Claude Desktop

Installation Steps

1. Install Required Packages

2. Update Configuration

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TTiagha commented Dec 2, 2024

p1Ktj1XWg1Bm commented Dec 14, 2024

TimHuey commented Dec 18, 2024

MCP servers fail to connect with `npx` on Windows #40

MCP servers fail to connect with `npx` on Windows #40

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