Claude Code says MCP failed to start

[Extarys]

Installed with uv on Fedora 42.

I've added the following to .mcp.json in my root project:

{
    "basic-memory": {
      "command": "uvx",
      "args": ["basic-memory", "mcp"],
      "env": {}
    }
  }
}

• I made sure I was on the main project
• I tested basic-memory tool to write a simple md and it worked.
• I deleted the 2 folders related to the package in ~ and relaunched in case it was corruption somehow

Terminal:

$ basic-memory tool write-note --title "First!" --folder "test" --content "Write your first note"
/home/user/.local/share/uv/tools/basic-memory/lib/python3.13/site-packages/aiosqlite/core.py:105: DeprecationWarning: The default datetime adapter is deprecated as of Python 3.12; see the sqlite3 documentation for suggested replacement recipes
  result = function()
# Created note
file_path: test/First!.md
permalink: test/first
checksum: a0c1d2a0

derek@pc:~$ basic-memory project default main
/home/user/.local/share/uv/tools/basic-memory/lib/python3.13/site-packages/sqlalchemy/sql/schema.py:3624: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
  return util.wrap_callable(lambda ctx: fn(), fn)  # type: ignore
Project 'main' set as default successfully
Project activated for current session

derek@pc:~$ uv tool update basic-memory
Nothing to upgrade

derek@pc:~$ uvx basic-memory mcp
[06/30/25 19:54:27] INFO     Starting MCP server 'Basic Memory' with transport 'stdio'                                                                                                                                             server.py:1307
/home/user/.local/share/uv/tools/basic-memory/lib/python3.13/site-packages/aiosqlite/core.py:105: DeprecationWarning: The default datetime adapter is deprecated as of Python 3.12; see the sqlite3 documentation for suggested replacement recipes
  result = function()

derek@pc:~$ basic-memory sync
Syncing project: main
Project path: /home/user/basic-memory
Project 'main': Everything up to date

Claude Code

╭───────────────────────────────────────────────────╮
│ Basic-memory MCP Server                           │
│                                                   │
│ Status: ✘ failed                                  │
│ Command: uvx                                      │
│ Args: basic-memory mcp                            │
│                                                   │
│ ❯ 1. Back                                         │
╰───────────────────────────────────────────────────╯

Any suggestions on what I can try next ?

[phernandez]

@Extarys I use basic-memory in claude code daily (on OS X), so I know it works. Can you give me a little more info?

• how did you install into claude code? your output looks correct, so just checking
• can you share your log file in ~/.basic-memory/basic-memory-mcp.log?
• you might also try starting claude with the --debug. It will show all errors from the mcps.

[Extarys]

Ah, thanks! I didn't know about the --debug arg :)

To install I manually edited .mcp.json in my project's folder, then seeing it didn't work, I edited ~~/.claude.json directly. I just tried removing those and use claude mcp add basic-memory -s user -- uvx basic-memory mcp instead, but the output are the same.

EDIT: I also tried with installing and running without uvx, same output.

claude --debug:

[DEBUG] MCP server "basic-memory": Connection failed: McpError: MCP error -32000: Connection closed
[DEBUG] MCP server "basic-memory": Error message: MCP error -32000: Connection closed
[DEBUG] MCP server "basic-memory": Error stack: McpError: MCP error -32000: Connection closed
    at Xn1._onclose (file:///home/user/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1333:14912)
    at _transport.onclose (file:///home/user/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1333:14231)
    at ChildProcess.<anonymous> (file:///home/user/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1335:1444)
    at ChildProcess.emit (node:events:518:28)
    at ChildProcess.emit (node:domain:489:12)
    at maybeClose (node:internal/child_process:1101:16)
    at ChildProcess._handle.onexit (node:internal/child_process:304:5)

MCP logs:

-01 07:43:35.069 | INFO     | basic_memory.services.initialization:initialize_file_sync:174 - Sync completed successfully for project: master
2025-07-01 07:43:35.070 | INFO     | basic_memory.services.initialization:initialize_file_sync:180 - Project master is now watching for changes
2025-07-01 07:43:35.070 | INFO     | basic_memory.services.initialization:initialize_file_sync:200 - Starting watch service for all projects
2025-07-01 07:43:35.071 | INFO     | basic_memory.sync.watch_service:run:94 - Watch service started

...
2025-07-01 07:20:07.166 | INFO     | basic_memory.utils:setup_logging:168 - ENV: 'dev' Log level: 'INFO' Logging to .basic-memory/basic-memory-mcp.log
2025-07-01 07:20:07.166 | INFO     | basic_memory.config:setup_basic_memory_logging:352 - Basic Memory 0.14.0 (Project: main)
2025-07-01 07:25:10.127 | INFO     | basic_memory.utils:setup_logging:168 - ENV: 'dev' Log level: 'INFO' Logging to .basic-memory/basic-memory-mcp.log
2025-07-01 07:25:10.127 | INFO     | basic_memory.config:setup_basic_memory_logging:352 - Basic Memory 0.14.0 (Project: main)
2025-07-01 07:27:03.287 | INFO     | basic_memory.utils:setup_logging:168 - ENV: 'dev' Log level: 'INFO' Logging to .basic-memory/basic-memory-mcp.log
2025-07-01 07:27:03.287 | INFO     | basic_memory.config:setup_basic_memory_logging:352 - Basic Memory 0.14.0 (Project: main)
2025-07-01 07:30:25.808 | INFO     | basic_memory.utils:setup_logging:168 - ENV: 'dev' Log level: 'INFO' Logging to .basic-memory/basic-memory-mcp.log
2025-07-01 07:30:25.808 | INFO     | basic_memory.config:setup_basic_memory_logging:352 - Basic Memory 0.14.0 (Project: main)

[phernandez]

Hmm, try this @Extarys and see if it works for you:

claude mcp add basic-memory uv tool run basic-memory mcp

example:

➜  test-claude claude mcp add basic-memory uv tool run basic-memory mcp
Added stdio MCP server basic-memory with command: uv tool run basic-memory mcp to local config
➜  test-claude claude
╭───────────────────────────────────────────────────╮
│ ✻ Welcome to Claude Code!                         │
│                                                   │
│   /help for help, /status for your current setup  │
│                                                   │
│   cwd: /Users/phernandez/test-claude              │
╰───────────────────────────────────────────────────╯

 Tips for getting started:

 1. Ask Claude to create a new app or clone a repository
 2. Use Claude to help with file analysis, editing, bash commands and git
 3. Be as specific as you would with another engineer for the best results
 4. ✔ Run /terminal-setup to set up terminal integration

 ※ Tip: Run /install-github-app to tag @claude right from your Github issues and PRs
╭───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Manage MCP servers                                                                                                                                                            │
│                                                                                                                                                                               │
│ ❯ 1. basic-memory  ✔ connected · Enter to view details                                                                                                                        │
╰───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
   Esc to exit

[Extarys]

Sadly didn't work (I removed it from all mcp files before testing):

[ERROR] MCP server "taskmaster-ai" Failed to fetch resources: [
  {
    "code": "invalid_type",
    "expected": "string",
    "received": "undefined",
    "path": [
      "resources",
      0,
      "name"
    ],
    "message": "Required"
  },
  {
    "code": "invalid_type",
    "expected": "string",
    "received": "undefined",
[DEBUG] MCP server "basic-memory": Connection failed: McpError: MCP error -32000: Connection closed
[DEBUG] MCP server "basic-memory": Error message: MCP error -32000: Connection closed
[DEBUG] MCP server "basic-memory": Error stack: McpError: MCP error -32000: Connection closed
    at Mn1._onclose (file:///home/user/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1336:14912)
    at _transport.onclose (file:///home/user/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1336:14231)
    at ChildProcess.<anonymous> (file:///home/user/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1338:1444)
    at ChildProcess.emit (node:events:518:28)
    at ChildProcess.emit (node:domain:489:12)
    at maybeClose (node:internal/child_process:1101:16)
    at ChildProcess._handle.onexit (node:internal/child_process:304:5)

@phernandez Do you think I should open an issue ?

[phernandez]

Yeah feel free to report an issue and send over any logs you have to help us debug. if you can include your system information too, python version, uv, whatver that would be helpful.

[phernandez]

Turns out theres a github button for that - #218. If you could add any logs you have that would be helpful