# Troubleshooting

Find solutions to common problems and learn how to debug issues with Nexus.

## Quick Debugging

### Enable Debug Logging
```bash
nexus --log debug
```

### Check Server Status
```bash
curl http://localhost:8000/health
```

### Test LLM Connection
```bash
curl http://localhost:8000/llm/openai/v1/models
```

### Common Error Codes

| Code | Meaning | Common Causes |
|------|---------|--------------|
| 401 | Unauthorized | Invalid or missing authentication token |
| 403 | Forbidden | Insufficient permissions or CSRF failure |
| 404 | Not Found | Model not configured or endpoint doesn't exist |
| 429 | Too Many Requests | Rate limit exceeded |
| 500 | Internal Server Error | Server configuration error or provider issue |
| 502 | Bad Gateway | Downstream server unreachable |
| 503 | Service Unavailable | Server overloaded or starting up |

## Getting Help

1. **Check the logs** with `--log debug` flag
2. **Review configuration** for typos or missing values
3. **Test components individually** before full integration
4. **Search existing issues** on GitHub
5. **Report new issues** with reproduction steps

## Next Steps

- Check [best practices](/docs/best-practices) to avoid common issues

Debug common issues and resolve problems with Nexus

Code	Meaning	Common Causes
401	Unauthorized	Invalid or missing authentication token
403	Forbidden	Insufficient permissions or CSRF failure
404	Not Found	Model not configured or endpoint doesn't exist
429	Too Many Requests	Rate limit exceeded
500	Internal Server Error	Server configuration error or provider issue
502	Bad Gateway	Downstream server unreachable
503	Service Unavailable	Server overloaded or starting up