MCP Server - error

Technical Help
1

Are you using our SaaS platform (Baserow.io) or self-hosting Baserow?

SaaS

What are the exact steps to reproduce this issue?

Hi everyone, have any of you tried the new functionality of the Baserow MCP server?
I tried it with the Claude desktop client and got the following error:
Could not attach to MCP server Baserow MCP

Here is my error log:
2025-05-01T17:11:27.342Z [Baserow MCP] [info] Initializing server…
2025-05-01T17:11:27.364Z [Baserow MCP] [info] Server started and connected successfully
2025-05-01T17:11:27.365Z [Baserow MCP] [info] Message from client: {“method”:“initialize”,“params”:{“protocolVersion”:“2024-11-05”,“capabilities”:{},“clientInfo”:{“name”:“claude-ai”,“version”:“0.1.0”}},“jsonrpc”:“2.0”,“id”:0}
[83599] Using automatically selected callback port: 3334
[83599] [83599] Connecting to remote server: https://api.baserow.io/mcp/WhdZqIUSiqlRfYxL4h2p5RTZVXZ7XzDF/sse
[83599] Using transport strategy: http-first
[83599] Connection error: Error: Error POSTing to endpoint (HTTP 405): Method Not Allowed
at StreamableHTTPClientTransport.send (file:///Users/rkrochmal/.npm/npx/705d23756ff7dacc/node

1 Like
2

The same is happening here. From Claude Desktop for macOS to Baserow. With/without -y, the same result :cry:

[10023] Using transport strategy: http-first
[10023] Connection error: Error: Error POSTing to endpoint (HTTP 405): Method Not Allowed
3

I’m receiving the same issue for MCP server on self host but it does work with the hosted version.

4

I also had the same issue.

I was able to solve it by uninstalling nodejs and installing it again. I also removed the node versions that I installed through nvm.

5

Thanks @frederikdc for response, I really appreciate it. I have also my local Baserow instance in docker desktop container and it works with Claude desktop client. Only Cloud Baserow instance is not working for me. Any suggstions?

6

Fixed: It worked after 2 days without changing any middleware settings on my laptop. But I don’t know what the probrem was.

Screenshot 2025-05-04 at 4.36.56 PM
Screenshot 2025-05-04 at 4.36.56 PM1540×860 62.5 KB

7

@frodoslav, so for you the MCP server is not working on SaaS, and for you @umbral it’s the opposite—the MCP server works on the hosted version and doesn’t work on self-hosted?

We are currently collecting feedback on this feature to analyze reported issues and make improvements. @frodoslav @umbral @skillhacker, please share as much detail about the problems you’re experiencing, and we will investigate them. :raised_hands:

8

Hi @olgatrykush, it’s already working. I don’t know why, but it doesn’t matter. I use it with cloud and also seflhosted version. Thanks.

Frodo

1 Like
9

In case you need to investigate this, let me add what happened (but it works now).

Claude Desktop for macOS and Baserow Cloud

  1. Add a setting to claude_desktop_config.json
  2. Launch Claude Desktop
  3. Error occurs
  4. Log says “Method Not Allowed”

After several attempts, I removed the setting from the config file. And 2 days later, I added the same setting to the config and it worked.

The error log (mcp-server-baserow.log):

2025-05-01T11:59:59.332Z [baserow] [info] Initializing server...
2025-05-01T11:59:59.393Z [baserow] [info] Server started and connected successfully
2025-05-01T11:59:59.981Z [baserow] [info] Message from client: {"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"claude-ai","version":"0.1.0"}},"jsonrpc":"2.0","id":0}
[30680] Using automatically selected callback port: 3334
[30680] [30680] Connecting to remote server: https://api.baserow.io/mcp/{MY_TOKEN}/sse
[30680] Using transport strategy: http-first
[30680] Connection error: Error: Error POSTing to endpoint (HTTP 405): Method Not Allowed
    at StreamableHTTPClientTransport.send (file:///Users/{MY_ACCOUNT}/.npm/_npx/705d23756ff7dacc/node_modules/mcp-remote/dist/chunk-H6WV3ZQP.js:6511:15)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
[30680] Fatal error: Error: Error POSTing to endpoint (HTTP 405): Method Not Allowed
    at StreamableHTTPClientTransport.send (file:///Users/{MY_ACCOUNT}/.npm/_npx/705d23756ff7dacc/node_modules/mcp-remote/dist/chunk-H6WV3ZQP.js:6511:15)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
2025-05-01T12:00:05.559Z [baserow] [info] Server transport closed
2025-05-01T12:00:05.560Z [baserow] [info] Client transport closed
2025-05-01T12:00:05.560Z [baserow] [info] Server transport closed unexpectedly, this is likely due to the process exiting early. If you are developing this MCP server you can add output to stderr (i.e. `console.error('...')` in JavaScript, `print('...', file=sys.stderr)` in python) and it will appear in this log.
2025-05-01T12:00:05.561Z [baserow] [error] Server disconnected. For troubleshooting guidance, please visit our [debugging documentation](https://modelcontextprotocol.io/docs/tools/debugging) {"context":"connection"}
2025-05-01T12:00:05.561Z [baserow] [info] Client transport closed

The config file (claude_desktop_config.json):

{
  "globalShortcut": "Alt+Cmd+Space",
  "mcpServers": {
    "fs": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
	"/Users/{MY_ACCOUNT}/Downloads"
      ]
    },
    "baserow": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://api.baserow.io/mcp/{MY_TOKEN}/sse"
      ]
    }
  }
}

Hope this helps :smiling_face:

1 Like
10

@skillhacker : what version of nodeJS do you have installed and are you using nvm for node version management?

12

Current version is 23.11.0 and I don’t use nvm. I use Homebrew for package management.

% node --version
v23.11.0
13

I have a problem as well, which is likely due to the size of the database, which may be too big for Claude: I have more than 5000 lines in total. It works well with a smaller workspace (200 lines in my case).

14

Thanks for reporting this @janb :memo: