MCP Server Internal Server Error Report

Issue Summary

The MCP server is not running properly when tested locally. Additionally, when attempting to mount it on a client site using Uvicorn, it results in an Internal Server Error (500). However, when tested with MCP Inspector and Claude Desktop, the server appears to be running correctly.

Steps to Reproduce

1. Run the MCP server locally.
2. Verify its functionality using MCP Inspector and Claude Desktop (works fine).
3. Attempt to mount the server on a client site using Uvicorn.
4. Observe the Internal Server Error (500) response.

Expected Behavior

• The MCP server should run properly when mounted on a client site using Uvicorn.
• API requests should not result in Internal Server Errors.

Actual Behavior

• The server runs successfully in MCP Inspector and Claude Desktop.
• When mounted using Uvicorn, the client site returns an Internal Server Error (500).

Environment Details

• Python Version: 3.13.2
• Package Manager: uv
• MCP Framework: FastMCP
• Deployment Setup:
  • Local Testing (Working: MCP Inspector, Claude Desktop)
  • Client-Side Mounting via Uvicorn (Error: Internal Server Error 500)

Logs & Error Messages

(Include any relevant logs, traceback, or console output here.)

Possible Causes Considered

• The server itself is running fine in other environments.
• The issue may be related to Uvicorn configuration or an incompatibility with MCP.
• Database connection issues or missing environment variables.

Additional Context

• If there are any configuration files, Uvicorn command-line options, or deployment settings that may be relevant, include them here.

Suggested Debugging Steps

• Verify Uvicorn logs for additional details.
• Check database connections and environment variables.
• Run Uvicorn in verbose/debug mode to identify specific error causes.
• Test with a different ASGI server (e.g., Daphne, Hypercorn) to check if the issue persists.

Action Required

Requesting assistance in debugging the issue and identifying why the MCP server fails under Uvicorn but works in other environments.