# fastapi.exceptions.RequestValidationError: JSON decode error
  Expecting value: line 1 column 1 (char 0)

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

## Root Cause

The client sent an empty or non-JSON body while the endpoint expects application/json.

## Version Compatibility

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

## Workarounds

1. **** (92% success)
   ```
   async def create(item: Item | None = None): ...
   ```
2. **** (88% success)
   ```
   from fastapi import Body
async def create(item: Item = Body(default=None)): ...
   ```

## Dead Ends

- **** — Header alone does not provide parseable JSON; still fails. (85% fail)
- **** — Parsing occurs before the handler in FastAPI. (90% fail)