# AssertionError: A blueprint's name collision occurred between <Blueprint 'api'> and <Blueprint 'api'>. Either specify a unique name or register them under different prefixes.

- **ID:** `python/flask-blueprint-name-conflict`
- **Domain:** python
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Two Blueprint objects with the same name are registered on the same app, or a blueprint is registered twice.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 2.x | active | — | — |
| 3.x | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   Give unique names: `api_v1 = Blueprint('api_v1', __name__)` and `api_v2 = Blueprint('api_v2', __name__)`.
   ```
2. **** (90% success)
   ```
   Register with a prefix: `app.register_blueprint(api, url_prefix='/v1')` and ensure names differ.
   ```

## Dead Ends

- **** — Name still collides; url_prefix does not change the blueprint name. (90% fail)
- **** — Second blueprint's routes are silently dropped. (85% fail)