Claude desktop connection failed

Claude Desktop Connection to Blender Fails with Timeout

Users of the Claude desktop application are experiencing connection failures when attempting to link with Blender through the Model Context Protocol (MCP). The mcp-server-blender.log indicates that the connection times out shortly after the uvx process is initiated, preventing successful initialization.

The Problem

The core issue manifests as a timeout during the initial handshake between the Claude client and the Blender MCP server. The log snippet shows the server starting and connecting successfully, but the client's initialize request receives a "Request timed out" error after approximately 60 seconds. This prevents the client from establishing a working session with Blender.


2025-10-12T06:34:45.785Z [blender] [info] Initializing server... { metadata: undefined }
2025-10-12T06:34:45.793Z [blender] [info] Using MCP server command: /opt/homebrew/bin/uvx with args and path: {
  metadata: {
    args: [ 'blender-mcp', [length]: 1 ],
    paths: [ ... ]
  }
} %o
2025-10-12T06:34:45.794Z [blender] [info] Server started and connected successfully { metadata: undefined }
2025-10-12T06:34:45.831Z [blender] [info] Message from client: {"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"claude-ai","version":"0.1.0"}},"jsonrpc":"2.0","id":0} { metadata: undefined }
2025-10-12T06:35:45.830Z [blender] [info] Message from client: {"jsonrpc":"2.0","method":"notifications/cancelled","params":{"requestId":0,"reason":"McpError: MCP error -32001: Request timed out"}} { metadata: undefined }

Root Cause: Dependency Download Timeout

The underlying cause is often a timeout related to downloading Python dependencies required by the blender-mcp server. The uvx tool, used to manage the server, may be attempting to download packages like pygments and pydantic-core during startup. If the download process takes longer than the MCP initialization timeout (typically 60 seconds), the connection will be terminated prematurely.

Solutions and Workarounds

There are a couple of approaches to resolve this issue:

1. Pre-caching Dependencies

You can pre-cache the required Python packages by manually running the blender-mcp command with the --help flag. This forces uvx to download and cache the dependencies before the Claude client attempts to connect.


uvx blender-mcp --help

This command triggers the dependency download process. Once completed successfully, subsequent connections from the Claude client should no longer experience the timeout issue.

2. Permanent Installation

Alternatively, you can install blender-mcp permanently using the uv tool install command. This ensures that the dependencies are always available and avoids the need for runtime downloads.


uv tool install blender-mcp

This command installs blender-mcp as a system-wide tool, making its dependencies readily accessible. This approach offers improved reliability and eliminates the potential for download-related timeouts.

Additional Considerations

Network Connectivity: Ensure a stable and fast internet connection during the initial setup. Slow network speeds can exacerbate the dependency download timeout issue.
Firewall Restrictions: Check for any firewall rules or proxy settings that might be interfering with the download process.
uvx Configuration: If you're using a custom uvx configuration, verify that it's correctly set up to access the necessary package repositories.
MCP Server Logs: Always consult the mcp-server-blender.log for detailed error messages and troubleshooting information.

By pre-caching or permanently installing the blender-mcp dependencies, you can significantly reduce the likelihood of encountering connection timeouts and ensure a smoother integration between the Claude desktop application and Blender.