# invalid_json

> The request body is not valid JSON.

**Invalid JSON** · HTTP 400

## What it means

The request body is not valid JSON.

## What to do

Send a JSON object with `Content-Type: application/json`.

## Example

```json
{
  "type": "https://api.bymundi.com/problems/invalid_json",
  "title": "Invalid JSON",
  "status": 400,
  "detail": "The request body is not valid JSON.",
  "code": "invalid_json",
  "requestId": "req_…"
}
```

How to read any error: [Errors guide](https://api.bymundi.com/docs/guides/errors.md).