# Debugging MCP Server Connection Issues: A Complete Troubleshooting Guide for Wordle MCP (Python)

> Troubleshoot MCP server connection issues for Wordle MCP Python. Learn to verify runtime status, check logs, validate API connectivity, and fix dependency errors for a seamless experience.

- Repository: [CSK/mcp-wordle-python](https://github.com/cr2007/mcp-wordle-python)
- Tags: how-to-guide
- Published: 2026-02-28

---

**Debugging MCP server connection issues for the Wordle MCP (Python) involves verifying container runtime status, checking FastMCP initialization logs, validating network connectivity to the New York Times Wordle API, and ensuring the `requests` dependency is correctly installed in the environment.**

The `cr2007/mcp-wordle-python` repository implements a lightweight FastMCP-based server that exposes the `get_wordle_solution` tool for fetching Wordle answers. When debugging MCP server connection issues, you must trace failures across the container runtime, dependency resolution, and external API boundaries.

## Understanding the Wordle MCP Server Architecture

### Core Components and Entry Points

The server architecture centers on the **FastMCP runtime**, which handles tool registration, client communication, and lifecycle management. The entry point is defined in [[`fastmcp.json`](https://github.com/cr2007/mcp-wordle-python/blob/main/fastmcp.json)](https://github.com/cr2007/mcp-wordle-python/blob/master/fastmcp.json):

```json
{
    "entrypoint": "src/mcp_wordle/main.py",
    "environment": {
        "dependencies": ["requests"]
    }
}

```

Key implementation details in [[`src/mcp_wordle/main.py`](https://github.com/cr2007/mcp-wordle-python/blob/main/src/mcp_wordle/main.py)](https://github.com/cr2007/mcp-wordle-python/blob/master/src/mcp_wordle/main.py):

- **Line 1**: Imports `FastMCP` from the `fastmcp` package
- **Line 13**: Instantiates `mcp = FastMCP("WordleMCP")`
- **Lines 30-68**: Defines `get_wordle_solution` wrapped with `@mcp.tool()` decorator

### Deployment Options

The server supports two primary runtime environments:

- **Docker**: Pre-built image `ghcr.io/cr2007/mcp-wordle-python:latest` provides isolated runtime with dependencies pre-installed
- **uvx**: One-line command `uvx --from git+https://github.com/cr2007/mcp-wordle-python mcp-wordle` runs via the `uv` package manager

## Common MCP Server Connection Failure Points

### Container Startup and Runtime Failures

Connection issues often originate before the MCP protocol even initializes. **Docker daemon failures** prevent the container from starting, while **image pull errors** occur when GitHub Container Registry is unreachable. If the container exits immediately upon startup, it typically indicates a missing dependency or entry point misconfiguration.

### Network and API Connectivity Issues

The `get_wordle_solution` tool makes HTTP requests to `https://www.nytimes.com/svc/wordle/v2/<date>.json` with a **300-second timeout** (`requests.get(..., timeout=300)`). The API imposes strict date validation:

- **Minimum date**: 2021-05-19 (Wordle launch)
- **Maximum date**: 23 days in the future from current date

Out-of-range dates return a structured error JSON rather than the solution data.

### Dependency and Import Errors

The [`fastmcp.json`](https://github.com/cr2007/mcp-wordle-python/blob/main/fastmcp.json) declares `requests` as a required dependency. If the runtime environment lacks this package, the server raises an `ImportError` during initialization before registering any tools. This manifests as a connection failure in the MCP client because the server process terminates prematurely.

## Step-by-Step Debugging MCP Server Connection Issues

Follow this systematic approach to isolate and resolve connection failures:

1. **Verify the server process is active**
   - Docker: Run `docker ps` and confirm the container `ghcr.io/cr2007/mcp-wordle-python` appears in the list
   - uvx: Confirm the terminal displays FastMCP startup logs without immediate exit

2. **Inspect initialization logs**
   - Docker: Execute `docker logs <container-id>` to check for `ImportError` or FastMCP registration messages
   - Look for the line indicating `get_wordle_solution` tool registration

3. **Validate network connectivity**
   - Test outbound connectivity from the container: `docker exec -it <container-id> ping www.nytimes.com`
   - Verify the host can reach the Wordle API endpoint

4. **Test tool invocation with valid parameters**
   - Use a date within the allowed window (e.g., `2024-02-01`)
   - Check for timeout errors indicating network latency exceeding 300 seconds

5. **Verify dependency installation**
   - Confirm `requests` is importable: `docker exec <container-id> python -c "import requests"`
   - Check [`fastmcp.json`](https://github.com/cr2007/mcp-wordle-python/blob/main/fastmcp.json) dependency declarations match installed packages

## Practical Debugging Examples

### Verifying Docker Deployment

When the MCP client reports connection failures immediately after configuration, verify the container runtime:

```bash

# Pull the latest image

docker pull ghcr.io/cr2007/mcp-wordle-python:latest

# Run with interactive flags to observe startup

docker run --rm -i --init -e DOCKER_CONTAINER=true ghcr.io/cr2007/mcp-wordle-python:latest

# In a separate terminal, check container status

docker ps --filter "ancestor=ghcr.io/cr2007/mcp-wordle-python"

# If the container exited, inspect logs

docker logs $(docker ps -lq)

```

If logs show `ModuleNotFoundError: No module named 'requests'`, the dependency installation failed despite the [`fastmcp.json`](https://github.com/cr2007/mcp-wordle-python/blob/main/fastmcp.json) declaration.

### Debugging uvx Execution

For environments using `uvx` without Docker:

```bash

# Verify uv installation first

uv --version

# Execute with verbose output to catch repository cloning errors

uvx --from git+https://github.com/cr2007/mcp-wordle-python mcp-wordle

```

Successful initialization displays the FastMCP server identifier `WordleMCP` and confirms tool registration. If the process exits silently, check `~/.cache/uv/` for corrupted package metadata.

### Testing Tool Logic Directly

Bypass the MCP transport layer to isolate API versus protocol issues:

```python

# Direct import from source

from src.mcp_wordle.main import get_wordle_data

# Test valid date within API window

valid_response = get_wordle_data("2024-02-01")
print(f"Solution: {valid_response.get('solution')}")

# Test boundary condition (should error)

error_response = get_wordle_data("1999-01-01")
print(f"Error status: {error_response.get('status')}")

```

This approach confirms whether the `requests` timeout (300 seconds) or the NYT API date validation is causing the connection failure.

## Summary

- **Debugging MCP server connection issues** requires checking three layers: container/runtime status, dependency resolution, and external API connectivity.
- The Wordle MCP server entry point is [`src/mcp_wordle/main.py`](https://github.com/cr2007/mcp-wordle-python/blob/main/src/mcp_wordle/main.py), which registers `get_wordle_solution` via the FastMCP instance defined in [`fastmcp.json`](https://github.com/cr2007/mcp-wordle-python/blob/main/fastmcp.json).
- Common failures include Docker daemon errors, missing `requests` dependencies, and Wordle API date validation errors (valid range: 2021-05-19 to 23 days future).
- Use `docker logs` to inspect FastMCP initialization and `docker exec` to verify network connectivity to `www.nytimes.com` before the 300-second timeout threshold.

## Frequently Asked Questions

### How do I verify the Wordle MCP server is running correctly?

Check active processes using `docker ps` to confirm the container `ghcr.io/cr2007/mcp-wordle-python` appears in the list, or observe the terminal output for FastMCP initialization logs when using `uvx`. Successful startup shows the server identifier `WordleMCP` and confirms tool registration without `ImportError` messages.

### What causes "connection failed" errors when connecting to the Wordle MCP server?

Connection failures typically indicate the Docker daemon is not running, the container exited immediately due to missing `requests` dependencies declared in [`fastmcp.json`](https://github.com/cr2007/mcp-wordle-python/blob/main/fastmcp.json), or the `uvx` environment cannot resolve the Git repository. Inspect `docker logs` for startup errors or verify `uv` installation with `uv --version` to isolate the runtime layer.

### How do I debug date validation errors in the get_wordle_solution tool?

The Wordle API accepts dates from 2021-05-19 up to 23 days in the future. When debugging, test with a valid date like `2024-02-01` first. If you receive a JSON response containing `status: "error"` and an `errors` array, verify the input date falls within the allowed window and check the 300-second timeout hasn't expired due to network latency.

### Can I run the Wordle MCP server without Docker?

Yes, you can run the server using `uvx` without installing Docker. Execute `uvx --from git+https://github.com/cr2007/mcp-wordle-python mcp-wordle` after installing the `uv` package manager. This method still requires network connectivity to fetch dependencies and communicate with the New York Times Wordle API endpoint at `https://www.nytimes.com/svc/wordle/v2/`.