# [Errno 98] error while attempting to bind on address ('0.0.0.0', 8000): address already in use

- **ID:** `python/uvicorn-port-already-in-use`
- **Domain:** python
- **Category:** system_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Previous uvicorn/gunicorn worker still holding the port, or another service bound to 8000 (common after Ctrl+C on reload).

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 0.100+ | active | — | — |
| 0.110+ | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   lsof -i :8000  # then kill -9 <pid>
   ```
2. **** (90% success)
   ```
   uvicorn app:app --port 8001  # use a free port
   ```

## Dead Ends

- **** — Reload spawns more workers; port stays held. (70% fail)
- **** — Same port conflict. (80% fail)