# werkzeug.exceptions.BadRequest: 400 Bad Request: Failed to decode JSON object: Expecting value: line 1 column 1 (char 0)

- **ID:** `python/flask-json-decode-error`
- **Domain:** python
- **Category:** data_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

request.get_json() was called on a request whose body is empty or not JSON (e.g., form-encoded or missing Content-Type).

## Version Compatibility

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

## Workarounds

1. **** (90% success)
   ```
   data = request.get_json(silent=True) or {}
   ```
2. **** (92% success)
   ```
   Check request.is_json before parsing: if request.is_json: data = request.get_json()
   ```

## Dead Ends

- **** — Still fails if body is empty or malformed. (60% fail)
- **** — Downstream code then receives None and crashes. (70% fail)